machines which I have made, am making, or intend to make, and some other stuff. If you find this site interesting, please leave a comment. I read every comment and respond to most. n.b. There is a list of my first 800 posts in my post of 17 June 2021, titled "800 Posts"
My farm neighbour handed me this tool which had come into his hands, saying “you’re a smart young fella, what is this for?” (He is 86 or thereabouts).
So I inspected it, confident that I could work it out.
Works off mains power, with a large aluminium heating plate. But what are those bolt on cylinders for?
Could it be a bending apparatus for plastic?
I did not know, so I took it to our next “Model and Experimental Engineers” meeting, handed it around, and asked for assessments, hoping that someone would have the answer. Most of the 15-20 members present had no idea. But a couple of guesses came close.
Then one said…. “I know. I will ask Google Lens.”
“What is that”? I said.
He used his smart phone, took a photo of the tool with Google Lens (of which I was totally unaware), and showed me and the rest of the amazed meeting the answer…..
Almost identical to our tool.
It is a machine for joining plastic pipes using heat to melt and weld the surfaces, and costs $AUD 24 – $71, depending on brand and options.
Well!
That was astounding. Asking your smart phone to identify an unknown tool, instantly and accurately, and showing where to buy it, and at what cost!!!! And not just tools…. anything!!
It is obvious that I am not up to date. And VERY impressed. With the tool, its price, and possible applications. But mainly with Google Lens.
At home I tried it on the TV, and an 1866 model cannon which I had made. It showed the TV screen amongst several options. It showed a photo of the model cannon, which I had posted on this site some years ago, and listed this site as the source, with no price, which is accurate because it is not for sale.
Amazing!
SO TRY GOOGLE LENS! It is free. Works on smart phones and computers. You take a photo using Google Lens, or use an existing photo, and the program does its best to match the photo with the closest images it can find. With remarkable accuracy on my PC and iphone.
BTW. After a year of relative inactivity in the workshop I have picked two items that I am interested in modelling. Not sure which to choose first, or even whether to work on both. More details later.
In 2015 or thereabouts I was persuaded by Stuart Tankard to get into CNC machining. So I bought a second hand Seig lathe which had been converted to CNC. The Seig was really a waste of money. Too small, too inaccurate, too flimsy. And the conversion, I gradually realised, had been done with the cheapest possible components. But it did awaken a world of possibilities. I made some simple shapes…. spheres, tapers,etc, and I started searching for a better machine.
I had offered to buy Stuart’s Boxford TCL127. Not suprisingly he declined. But he did know where there was an identical one which might be for sale. Long story short, it was available and I bought it.
Now, what to make first?
Hmm…. what about a cannon? I had no interest in cannons, but the shape seemed suitable, so I did turn a long gun barrel, and that was fine, but the Boxford has one major limitation. The maximum size object it will handle is 127mm long, and 127mm diameter. So my cannon barrel was a bit pathetically small.
I showed the barrel to my model engineering club, and Bob, a senior member, offered me the use of his CNC lathe. So in 2016, I made a 24 pounder 1779 naval long gun, scale model about 300mm long. It turned out quite nicely, and I became very interested in the history of cannons as well as the machining aspects. Then I made a 32 pounder carronade circa 1805, at the same scale. And then an1866 rifled muzzle loader 80 pounder, and a 110 pounder rifled breech loader, and a1465 Ottoman bombard, and possibly more to come. None of these, I must mention, are capable of being fired.
But back to the long gun and the carronade. They were finished, as far as I was concerned, except for the cyphers on the barrels. Royal Navy guns which were made for HM ships always had (as far as I know), a moulded or carved cypher of the reigning monarch. The British monarch in 1779 and 1805 was George the third.
Summer has finally arrived in Southern Australia. 33 centigrade yesterday, and 40+ today. Too hot for the workshop, but not for Stuart T’s 30 watt fiber laser.
The 24pr 1779 naval long gun, with King George 3 cypher, expertly lasered by Stuart T.The 1805 Carronade with its George 3 cypher.The cypher is 22mm x 10mm. The lasering took about 2 minutes, after fiddling with the positioning and focusing and settings, and a test run on some scrap. Can’t remember where I found the image. The close up photo shows my substandard finish turning, as well as the superb result from Stuart’s lasering. After lasering, the lasered cypher is blown with compressed air to clear dust from the grooves, then a rub with 1200 grit emery paper, then some Brasso.
“GR” George Rex.
“HONI SOIT QUI MAL Y PENSE”
Description
Honi soit qui mal y pense is a maxim in the Anglo-Norman language, a dialect of Old Norman French spoken by the medieval ruling class in England, meaning “shamed be whoever thinks ill of it”, usually translated as “shame on anyone who thinks evil of it”. Wikipedia
It is about 3 weeks since I had my gall bladder removed and I am not yet 100% recovered. Pain free, so I presume that the pancreatitis has settled, but not feeling very energetic. Improving a bit every day. And helped by the readers and friends who sent me their best wishes. Thank you guys.
My car is a 12 year old BMW which I bought new. 200,000 km, twin turbo diesel X5. Very comfortable, versatile, economical, safe (5 star rating in Oz). I drive it carefully, regularly serviced, and it has been very reliable. I have considered changing it for a hybrid, smaller vehicle, but so far nothing has tempted me enough, so I am just hanging on to it.
But one irritating problem is that the driver’s seat leather upholstery had worn through where the squab is rubbed when entering and leaving the vehicle, and the stuffing was starting to protrude and come out.
Now, let me state that when I bought the car, I did not have the level of vegetarian, anti animal cruelty opinions, that I now have. For the past decade I would not be responsible for killing and suffering of cattle for meat, or leather for upholstery. However, I do regret not having made that change much earlier in my life. But neither am I going to waste the resources which went into the shoes and vehicles purchased prior to having my eyes opened.
Back to the BMW seat. I spotted this advertisement recently for a self adhesive leather repair material. The material itself is not leather, but the video attached to the ad looked fairly promising so I bought a sheet 1.36m x 600mm and some other items which were all delivered in good condition about 3 weeks later. So far, my experiences with Temu.com have been very good, including this order.
The material cuts easily with scissors and is slightly stretchy. The backing peels off easily. A practice run with a small piece demonstrated that the glue grips immediately, and is quite tenacious. There is a small window of time to position the piece accurately, as long as the area of contact is still small.
I quickly realised that the seat squab repair was going to be difficult, because the seat has curves in multiple directions, and I wanted the repair edges hidden within the existing leather joins. I initially tried to use a single piece for the entire repair, but that proved to be beyond my capabilities. Probably an expert repairer would have managed, but I decided to use 3 smaller pieces, and hope that the joins would not be too obvious.
Part way through the job I starting taking some photos. Unfortunately I don’t have any shots of the “before” situation.
The first piece of patch. Looking at the seat from above. One edge of the patch is tucked into the outside join in the worn leather, and the patch is progressively smoothed down while slowly removing the backing paper. Thorough initial cleaning of the leather with a damp cloth. This patch covers the worst split in the leather. The second edge is cut carefully, allowing about 2-3mm extra material to be pushed into the leather join. I bent a piece of copper wire (just seen) to do the pushing, to avoid cutting the seat leather or existing leather stitching.I used a Sharpie to mark the cutting lines, but extra trimming was needed as the repair piece was fixed into position. This is the final patch. It was the most difficult.Copper wire pushing tool. The repair pattern is not identical to the original, but it passes cursory inspection.The final result, with the tools used. The tool with the white plastic handle came from my wife’s sewing kit. The ruby ball was also a good pushing tool. The scissors top were from my microsurgery kit, but they were a bit too delicate for the job.
I will remove the Sharpie lines. Time will tell how well the repair lasts. At least it has stopped the seat stuffing coming out.
I was using my big Chinese lathe to make some mounting plates for the wheels of a catamaran beach roller about 2 weeks ago.
It was a very warm, very humid day, but the job was going well.
Suddenly, I felt a nasty pain in my upper abdomen or low central chest. It was severe, constant, and associated with profuse sweating. I felt faint. I did manage to stop the lathe spindle, but the pain was so severe that I moved away from the lathe and out of the shed, to the home building about 20 meters away. I was aware that I was staggering and close to losing consciousness.
I had a cold drink of water, sat down, then lay down flat on the floor. The pain was unremitting.
Heart attack? Seemed a bit low, but very likely. No heart history, but I am 73, and have high blood pressure. Rang my wife, but she was too far away to come. I mentioned the ambulance. She said “just do it”. Yep. Rang 000, was transferred to the ambulance service, and within maybe10-15 minutes the ambos arrived. Meanwhile I rang my neighbour, who came immediately. I asked him to turn off the workshop machinery and lock up the buildings and vehicles.
The pain was still intense and constant, but movements made it worse, so I lay very still, and closed my eyes in order to concentrate on coping. Apparently, I was as white as a ghost when the ambos arrived, and filthy of course, and drenched in sweat, laying still. They told me later that when they first saw me, they feared the worst.
Some oxygen, intravenous fluids and a pain killer improved the situation a bit. Then with sirens blaring they took me to the local public hospital, about 20 minutes away. Immediate admission to the Emergency Department. Some concern because my pulse was dipping as low as 20, and my BP up to 200/110. ”Am I going to die?” I wondered. But it was all out of my control, so I left it to the expertise of my professional ex-colleagues.
A cardiac event, or dissecting aneurysm, or upper abdominal event were the different diagnoses explored, and I underwent continuous heart monitoring, vital signs, and blood tests. Powerful pain killers were effective and I felt vaguely removed from the action. Then a CAT scan, an Ultrasound, and the next day an MRI scan and the diagnosis settled on pancreatitis caused by gall stones with a severe vagal effect causing the very low heart rate, and pain pushing up my BP. I seemed to have blood tests every hour or two.
A day in Emergency, 2 days in the surgical ward, then a recommendation for removal of my gall bladder and stones when the pancreatitis had settled somewhat.
My gall bladder was removed with key hole surgery (laparoscopy), one week after the initial event, and I was discharged home 2 days later, where I am now typing this record. I was so dosed up on painkillers that some details might be out of order. One day I remember seeing people and actions that I knew were not real. I was hallucinating. But it was very interesting, entertaining even. It was like watching a strange TV show inside my own brain. I kept that detail to myself.
Now, I am still on painkillers, but mainly for the pancreatitis, which might persist for another week or two, according to the surgeon. And the 4 small cuts on my belly give a twinge if pushed. But I feel SO much better. And so grateful that I live in a country where adequate and expert medical and nursing care, and ambulance services exist. And that we are not being bombed out of existence by a neighbour who is clinging to his dictatorial power, or at war with a neighbour who has a different name for God.
But when I finally caught up with the news, I was disgusted and angry to learn that a statue of one of my hero’s, James Cook, had been vandalised with an angle grinder. I do hope that they arrest the culprits very soon, and jail them. Whether they are agents provocateurs, or radical activists, they have NO right to vandalise the statue of arguably the greatest navigator in human history.
Normally on Australia Day, 26 January, I hang out an Australian flag, AND an Aboriginal flag. This year I am not in the mood. For the record, IMO, Australia Day should continue, but if 26 January is offensive to a majority of the descendants of our original Australians, then I would support a change of the date.
Enough of my rambling rant. Back in action after a few days rest. I hope.
Depending on the reactions to this post, I have several more Geelong bridges in mind, including one which was designed and built by an engineer who became Australia’s most renowned general, another named after the Geelong person who build the world’s first commercial refrigerator, and another which was designed by, arguably, the most famous British engineer of the nineteenth century.
My interest in bridges is long standing, and received a recent boost when I purchased a drone with an excellent camera. It is 5 years old, but in pristine condition. It was so unmarked that I suspected that it had never been flown.
It is a Mavic 2 Pro. I got it for less than 1/3 of its new price. It is now considered older technology, having less flight time than the newer ones, less obstacle avoidance, and possibly slightly noisier. What it does have, unlike the newer ones, is a camera which was designed by Hasselblad. I am still learning how to fly it, how to use the camera settings which are almost as extensive as my Nikon SLR, and how to shoot and edit videos.
The video about the aqueduct is the second one I have shot with the Mavic 2P. It is far from perfect, but is significantly better than the first one. I will reshoot the first one and post it later.
The video lasts 7-8 minutes. There is no narration, because I have not yet worked out how that is done. So read the captions.
The subject is not for everyone. But let me know whether it and the proposed successors would be of any interest.
You can click on the arrow in the pic, or go to YouTube to see it as full screen.
Almost 25 years ago I contracted an electrician to lay 220 meters of electrical cable to where we intended to build a house on our rural property. The cable route was across planned irrigation lines, so needed to be positioned and buried first.
The house was never built, and we sold most of the property about 10 years ago.
I used a tractor to pull out the 660-700 meters of cable (220 x 3 cables, plus some extra), in several pieces and unfortunately there were too many breaches in the insulation to be reused as electrical cable. It was coiled on a wooden drum, and was in my way on many occasions until I finally got around to dealing with it recently.
The cable had cost around $AUD3000 in 1998. In 2023 I calculated that as scrap copper it would be worth almost as much, ignoring inflation. But still $2-3k.
So, I lashed out, and on Ebay purchased a wire stripper for $60. It has a handle to pull/push the cable over a sharp wheel, and that wheel cuts a slit in the insulation, which then peels off pretty easily. The handle can be replaced with a drill, and with ~700 meters to strip, that’s what happened.
Watch the video to see the stripper in action.
I cut the cables into 1.5-2.5 meter lengths so I could easily handle the heavy cables.
The wire stripper was pretty solid, and well constructed and designed. I did bolt it to a steel base, which was then securely clamped to the trailer. The infeed arrangement was more suitable to undamaged cable than my traumatised cable, but it worked well enough. I wonder if a cone shaped infeed hole would have worked better than the simple hole in a thin plate as supplied, but hey, it was $60, not $600 or $6000.
My original plan was to sell the stripped cable as scrap copper for about $7 per kilogram. But looking at Ebay I note that 1kg copper ingots are advertised for $AUD110-130.
So, I am considering making some ingots. It should not be too difficult to make or purchase some 50mm x 50mm x100mm moulds, and I have a furnace. Hmmm. Maybe a test run?
The AI Assistant supplied by WordPress suggested that I add extra details about working with electrical cable in a wire stripper, so I add the following suggestions for your consideration…..
…..make sure that the electrical cable is disconnected from the electricity supply BEFORE pulling it free with a tractor, and definitely before stripping off the insulation.
I am back. Looking at my photos over the past month or more, not much of interest to my regular readers. In fact, very little time spent in the workshop. I have been chauffeur for SWMBO, to and from hospital and medical appointments. Buying groceries. Cooking. Infrequent visits to GSMEE.
But, there was one day in Melbourne where I had a couple of spare hours, so I visited a cannon which has been on my bucket list for several years. Two cannons actually, but virtually identical.
High St, Northcote, Melbourne, (Victoria, Australia for my OS readers).
And on the other side of High St is another gun of the same type. It is 5.88m/ 19′ long….
…and has an 8″ /203mm rifled bore. The bore serves as a rubbish bin for the local morons.
My artillery references categorise these guns as Armstrong pattern, breech loaders, of approximately 1885 vintage.
The Northcote guns have carriages which are naval types, and were possibly originally mounted on the gunboats HMVS Albert and HMVS Victoria. The barrels are the same as others which were originally mounted as garrison guns at South Channel Fort, Port Phillip Bay, Victoria. The Northcote barrel trunnions are covered, but said to be numbers 4312 and 4266. There is no barrel weight visible but these guns typically weighed just under 12 tons each. The slides are missing, but would have been pivoted at the front end.
The large breech mechanism is missing smaller removable components but is still impressive. The diameter of the breech is 918mm.
Said to have a range of 7500m. Projectile weight 95kg / 210lb
So. Will I model these guns? Without plans or good photographs of intact carriage and slide, probably not. But if I can locate such details……??
BTW. I have decided to sell my 3″ Fowler traction engine, tender, and coal, on a fitted 6’x4′ trailer with winch, toolbox and ramps. Full construction plans. It is running nicely with its new crankshaft, and has had boiler certification recently renewed until 2027. It has various improvements since this photo was taken, including working steam winch, steam injector, steam driven water pickup, new mechanical oiler, relocated hand pump, and more. Best offer around $AUD20k. Please, no tyre kickers. See previous posts for more pictures and videos. Inspection at Geelong, Victoria.
Swen Pettig (secretary of GSMEE) and I flew to Hobart 2 weeks ago to inspect, measure, and photograph the Jessop and Appleby crane at Constitution Dock, Hobart. We had become interested in the crane when plans for a 1:12.7 scale model appeared on Model Engineering Website. The plans were expertly drawn up by Julius deWaal, using information, photographs and some original drawings which were supplied to him by Tony Sprent AM, who lives in Hobart. More about Tony later. We contacted Tony, and he arranged with the authorities that we could clamber all over to get the information that we needed. We could have just used the deWaal plans to make the model, but there were some aspects, particularly regarding the boiler, that we wanted to check.
Firstly some photos of the crane….I took almost 200 shots, here are a few.
The crane used to run along dock edge rails. Now it rests on wooden blocks. It weighs 75 tons and was rated to lift up to 25 tons. The curved structure at the rear is a counterweight. Counterweights bolted under the swiveling carriage have since disappeared. The engine is a twin cylinder double acting steam engine. The boiler was rated for 75psi and usually fired with wood.
The water tube boiler is almost 3 meters high. It is currently unfit to operate. Unlike many old boilers, many of the brass fittings have survived.
The lifting cable drum, and some of the 20+ gears. It will be a challenging model to build.
Swen and Tony inspecting the sprockets and chains for the driving wheels.
Swen has started on his model. Tony Sprent is well into his. I am yet to start.
Tony, in his well organised, well lit, workshop. And his model which he estimates is about 2/3 built. The jib is on the bench at rear.
Tony’s counterweight container. We wondered what it would have contained. And some of the many gears.
The jib for Tony’s model.
Tony has had an interesting career. In brief, he studied physics and geology at university, then surveying and worked as a surveyor in Tasmania. Later he achieved a PhD, after researching and pioneering the use of lasers in surveying. This was back in the 1970’s (I think). He was awarded an AM for his volunteer work, amongst other things, inventing and designing mechanical appliances for disabled people, over many years. Now well into his 80’s Tony is still very active, constantly learning, designing, and making things. He is fairly computer capable, but he prefers a drawing board to CAD, and his lathe and mill are manual, although he is happy to utilise his machine DRO’s. It was an absolute pleasure to meet Tony, and we will continue to communicate with him. Who knows? We might even be able to entice him to the mainland to give our society a talk..
This morning at 6:45 it was 4 degrees C, clear blue sky, about 30″ after sunrise. About half of the moon was visible. So I grabbed my Nikon P1000 and tripod and took some shots and video.
At this time of day with the sun newly risen some atmospheric wavering is expected. Earthquakes due to passing trucks.
But I am quite pleased with these first efforts on the “moon” setting.
P.S. on closer inspection, the stills were shot at only at only 1mb, and 600mm lens setting. I will be able to get much sharper images at the full 16mb, and digitally enlarge them with post processing. Still plenty to learn about this camera.
I bought a travel camera in 2019 prior to my trip to UK. It was quite small in comparison to the Nikon SLR’s which I had used for several decades. And it took very good snapshots. Wide angle to telephoto (24-200mm). And video.
Since then, for this blog, I have used an iPhone X almost exclusively, because the shots are quite acceptable, and most importantly, it is always immediately available, in my pocket. The Lumix and iPhone both take reasonable videos.
However, when a friend showed me some shots of the moon taken with a Nikon Coolpix 900, I have wanted one of those big, heavy, mirrorless , behemoths. I watched Ebay from time to time, but they always looked a bit pricey. And the camera size is daunting. And not that I take telephoto shots often. I have a few Nikon telephoto lenses, but nothing spectacular. Catadioptric lenses looked interesting, but expensive, heavy to carry around for the odd shot.
Then recently I saw a used Nikon Coolpix P1000 which looked promising, and placed a bid. I felt disappointed when I was outbid by one dollar. Esnipe probably. So when another used one appeared as a “buy it now”, I did. Ebay had a 10% off deal. And the price was quite acceptable. $AUD 945. Said to be “near mint condition”. I am a bit chary of buying second hand after a few unfortunate experiences, but there was a 30 day return option. So I bought it.
It was not “near mint condition”.
It was brand new, unused. The cables were in their sealed plastic bags, obviously never been unwound. The camera was factory clean. The firmware was version 1.1. so I think that the camera was new old stock. Simple business to upgrade to version 1.6 of the software. And so far the camera works perfectly. For once I think that I scored a bargain.
The new Nikon Coolpix P1000, and Panasonic Lumix LX100-2. The Lumix is no slouch, quite good in fact. And easy to carry in a pocket.
The Nikon is BIG, and pretty heavy.
….and that lens is 24mm widish angle (35mm equivalent) to 3000mm telephoto, when extended. And there is x4 digital zoom on top of that 3000mm. So as a telescope equivalent it behaves a bit like a 12,000mm lens.
There are plenty of reviews of the P1000 on YouTube, so I am not intending to compete. Just a few of the first photos which I took, before reading the instructions. Blew me away!
A view of a tower on the hill about 1km distant. 24mm. Mild wide angle. 2.2mb. Tripod for all of these shots.47mm. About the same as naked eye. 2.3mb. (it can go up to 16mb.)97mm. mild telephoto. 2mb.400mm. 1.7mb. (Since then I have learned how to increase the pixel count, which would have improved this picture quality.)930mm. 1.8mb.2000mm. 1.8mb3000mm. 2mb. f8. 1/500s, On tripod of course. M8 U bolts?
And 3 more shots at the extremes. Still set at low resolution, according to the info screen.
Looking towards the front gate, late afternoon. Note the dead, high branches. A sign of poor rainfall causing die back. 50mm, f3.2, 1/1600s. Camera deciding the exposure settings on automatic.See the birds on the dead branches? 200mm. 1.8mb. 1/1000s3000mm, 2mb, f8, 1/500s. At this magnification, even on a tripod, there was some camera shake. Next I need to learn how to set the shutter delay.
I am going to have some fun with this camera. Can’t wait to take some moon and planet shots. And infrared filter coming. And I am now shooting at 16mega pixels, after skimming through the manual.
I visited this museum 11/8/23, with my wife, mainly to examine what is possibly the oldest exhibit, the 1863 Armstrong rifled breech loading cannon. See previous post. (p.s. there is a 6pr carronade, circa 1800 which is older.)
The museum is located on the Bandiana Army Base, so photo ID is required before entrance to the base. Entry was $AUD5 each. The exhibits are located in a very large, wooden framed shed, and 2 exterior yards.
Photography is unrestricted inside, but exterior shots must be directed towards the museum, or close ups. Photgraphy of the base itself is prohibited.
We were greeted by a friendly staff member outside the entrance, and shown inside.
The ticket office put me in mind of the Luna Park entrance.
Then we were accompanied by a staff member outside, where I examined the 1863 RBL. I had some questions for which another staff member retrieved files and read to me, regarding the Armstrong’s provenance.
That done, we wandered at our own paces around the museum interior. There were trucks, tanks, weapons large and small, documents, captured trophies, regimental lists and uniforms from all theatres of war involving the Australian Army. Many were impressive. Some were gruesome. All were interesting. Some were very moving. I took a few photographs. In no particular order…..
A video of the Japanese surrender at Tarakan, and one of many confiscated officer’s katanas.Lee Enfield rifles. There were many cases of rifles, machine guns, grenades, bayonets, uniforms. Australia’s own submachine gun…. the reliable Owen.M60 Machine gun. (I had to carry one of these when I was in the CMF over 50 years ago. A heavy mongrel. Fun to shoot. But terrifying to see the result at the target. A 44 gallon drum reduced to small bits.)A drip rifle. Designed to fire unattended, after a prolonged interval, having been set up by a departing soldier from Gallipoli, to mislead the Turks about the evacuation.I was once told by a military person that wounding is preferable to killing, because a wounded soldier removes others from the battle-field to carry the wounded and provide care. A reminder that war is a nasty business.Captured at TarakanCaptured in North Africa.Australia’s largest army museum, in a wood framed shed. The staff were a bit apologetic about the shed, but I thought that it was interesting. Reminded me of the Murtoa Stick Shed.WW1 truck. Solid tyres. Side valve engine.WW2 and later, Studebaker 10 wheel drive truck. Crash gear box. Top speed in lowest gear was 2 mph. But it was almost unstoppable in the roughest conditions. I was in a CMF transport company, and we drove these cold, noisy, impressive vehicles. Now of historic interest only, although this one is still registered.150mm artillery. 40km range.Heavy recovery vehicle.Arguably the most important military hardware of WW2. The Russian T34 tank. 84,000 were built.… and they were not bothered about fettling the castings!Arguably the least impressive WW2 tank. The British Matilda.
We were there 2 hours. That was SWMBO’s limit. A quick look around. The highlights for me were the Armstrong cannon, the Studebaker truck, and the T34. But there were so many items of interest. I would like to go again someday.
I must particularly commend the staff, who were all exceptionally friendly and helpful.
This is the model which I made of the 1861 Armstrong rifled breech loading cannon. It was made from drawings obtained from several 19th century books, internet photos, and a detailed Fusion 360 drawing purchased from ETSY. It is mounted on a “garrison” (land based) carriage and slide.
As you can see, it is very detailed, down to the square nuts and bolts, Smith’s elevating screw, and Queen Victoria’s cypher. But there was one detail which I had not been able to find anywhere. And that was whether or not there was any information stamped or engraved onto the muzzle of the barrel, like on the 80 pr RML which I modelled several years ago.
The model 80pr muzzle loader.Not a good photo, unfortunately. Very magnified. The text reads “Marshall’s Iron” and refers to the innermost cylinder which was made of a higher grade of iron than the outer layers, and could even be removed and replaced if worn out. This tiny detail was lasered onto the model 80pr bore by Stuart T, and if I could confirm that there was a similar inscription on the 110pr, would have asked him to do likewise again.
I had never actually seen an original of a 110pr RBL, so was quite excited when I read that one existed 400km away, at Wodonga, Victoria. So off we drove (SWMBO and I), after contacting the Australian Army Museum at Bandiana, Wodonga and obtaining permission to take some photographs.
The museum itself will be the subject of a separate post. Suffice it to say here that it was excellent!
The 1863 Rifled Breech Loader, black powder naval cannon was a different story.
Me, feeling a bit disappointed, but not too surprised. The carriage has the shape of a naval mounting, and there is a cap on the trunnion which would not have been fitted to a garrison (land based) gun. The carriage has signs of torch cutting and arc welding. The traversing platform could be an original naval version. All bronze fittings and many iron ones are missing.Breech block in situ. I am pretty sure that this is a modern reproduction. The handles are not hinged, and arc welding was not used in 1863. And there is no flash pan/vent. There is a statement that all weapons in the museum have been rendered incapable of being fired.This breech block is welded to the slide, probably to prevent a careless tourist from dropping 136lbs onto his foot. Pretty sure that the projectiles are reproductions too.I did not bother with a photo of the muzzle. The gun has so much thick paint that all markings are hidden, even the big ones on the trunnions. Oh well. The museum itself was great. And the 800km drive was lovely.
Most of the components of the vertical Southworth pump have now been machined, and following are some photos of the assembled bits. Not a final assembly, because the gaskets are yet to be fitted. My friend Stuart is currently, or possibly has already, cut out the gaskets on his CNC laser.
I did not make the external valves on the exterior. They were mostly sourced from sales of a deceased steam model maker. In using the parts on the Southworth pump, I hope in will be seen as a compliment to that maker, acknowledging his efforts. Thanks Harry.
The vertical Southworth steam powered boiler feed pump stands 150mm/6″ high. At top is the steam cylinder, piston, steam chest and steam chest lubricator (also made by Harry C.). At bottom is the actual pump. Yet to fit the gaskets and pump valves, and to block the holes shown, which were required during machining but become permanently closed now that machining the internal cavities is complete.Slightly different view, from above. The red handled pliers are Knipex parallel jaw pliers, which have been invaluable during this project. I have 3 sizes of these pliers, and will eventually have the full range. They are not cheap, but worth the cost.The steam chest, with cover removed, showing the 2 valves. On the right is the pilot valve which is activated by a lever from the piston rod. On the left is the shuttle valve which is activated by steam from the pilot valve through hidden passages, and which directs steam to the main piston. Now that I have made the parts and assembled them I am getting some comprehension of how this pump actually works! This photo shows that the taper on the steam entry valve needs some tidying. The copper washers under the 2 external valves are compression types, which are very useful in positioning those valves when the threads don’t exactly finish where the maker wants.
So, that is progress to date. A few more parts to make and install. Then to make various adjustments and get the Southworth pump functioning.
Coming up later this week. A visit to The Army Museum at Bandiana, Wodonga, Victoria, to see the Armstrong 110pr (110 pounder refers to the weight of the projectile the 1861 cannon could fire) breech loading cannon barrel, which I modelled last year from drawings and photographs and 19th century book descriptions. I am hoping that original inscriptions and engravings will still be visible on the barrel so I can add them to my model. As far as I am aware, this barrel is one of only two existing examples in Australia. And of course I will be touring the rest of the museum taking photographs to post here.
I will post progress in making this 6″ pump. I started making it 4-5 years ago, but put it aside when the horizontal version worked so well. See the previous post to see a video of the horizontal 2 cylinder pump filling the 6″ vertical boiler.
So, 2 workshop sessions later, and I have made the piston rod with steam and water pistons, and the studs which support the steam and water cylinders.
Doesn’t sound like much, for 2 whole sessions of 4-6 hours each, does it? But there it is.
First the studs.
They have to be identical lengths, with an M3 thread at each end. And a central narrower section with a curved end fillets. I decided to CNC the central section, with an Unbrako stud held in an ER collet (left) and a cap screw (right) in the tailstock.
The stud right with M3 threads at each end. At left, the narrowed section with curved fillets. The cap screw fitted nicely into tailstock and the Unbrako thread left into the headstock. The locknuts were required to prevent unscrewing during turning.The aluminium insert worked nicely on the brass studs. 2000rpm, F50mm/min. 1985 Boxford TCL 125 CNC lathe.
Then the single piston rod, 4mm diameter, with the large steam piston, and small water piston.
The pistons were drilled and tapped, and turned to exact size on the piston rods with a sharp HSS cutter and 0.25mm depth of cut.
The grooves for the O rings were made with a parting tool. Depth determined from a “Machinerys Handbook” table, and the width 50% larger, as specified. Unfortunately I damaged the O rings during insertion into the cylinders. But I had some Viton spares, and filled the sharp edges of the cylinder bores before trying them, with better success.
For my next project I have decided to finish a Southworth Pump which I started several years ago. I purchased castings and plans for both a horizontal pump (which I completed), and a vertical pump which I did not complete because the horizontal version suited the purpose perfectly.
Here is a video of the horizontal pump, which is being used to supply water to a 6″ vertical test boiler. You can watch it by clicking on the red arrow, or opening YouTube.
So that one is in use, and now I have found the box of parts and plans for the vertical version, which I now feel the need to finish.
7 pages of A4 plans, water pump left, steam cylinder and chest right. Unfinished pistons, and 2 plugs not yet identified.page 1 of the plans. The big components are mostly machined. Quite a few small ones to come. The cap screws are temporary.
Looking forward with some anticipation to getting back into this one.
I made these gates under the supervision of my blacksmith – welder friend Tony, about 45 years ago. They performed well until ~35 years ago, when a builder, who was doing an extension on our house, backed his ute into one of the brick pillars which supported one of the gates, and broke the pillar. He fixed it, sort of, but the gates were never quite straight after that.
Then about a year ago, I backed my ute into the damaged pillar, and really wrecked it. It was dangerous, so with the help of a strong friend, the gates were removed, and the pillar was demolished down to the intact base. This was also urgent, because there is a website titled “Shit Brick Fences of Melbourne”, which shows photos of, well, you know, a site that I did not want our front fence to appear on.
After these “adjustments”, the distance between the gates was slightly reduced, and in some weathers they would jam closed. Plus, they had not been repainted in 45 years, and were rusted through in places. So, I needed to cut out the rusted sections and weld in new steel, and take about 20mm off the width of each gate.
Two problems about doing those things. First, my welding skills have deteriorated over the years due to lack of practice and deteriorated eyesight. So there was a lot of use of the angle grinder to tidy up the welds. And repainting should help to disguise my poor welds. Secondly, these iron gates are VERY heavy. I can just manage to lift one end of each gate. And thirdly, we live on a road with a public footpath, so I had to be constantly on the lookout for pedestrians to avoid exposing them to welding flashes and showers of grinding sparks. I did much of the work well down the house driveway, and when I moved them from welding position to the posts, struggled with early attempts due to their size and weight.
Then I retrieved a moving trolley which had been made many years ago by my father. It has a simple low wooden frame, and the “wheels” are from an ancient washing machine with a mangle. The mangle rollers have a thick rubbery covering which allows them to cross small obstructions. It worked like a charm, and I was able to wheel the gates with only a small amount of huffing and puffing.
I redesigned and remade the bottom hinges. There is a 16mm ball between the hinge post and the top cover. The accumulated dirt etc conceals my poor welding. Some new paint, and a finial required. And who knows, maybe a remote controlled gate opener one day?
She Who Must be Obeyed, SWMBO, has some remarkable attributes. First, she has very good taste, as evidenced by the fact that she married me.
Second, she is smart, personable, and in my eyes beautiful.
However, after we were married (having “gone out” for 6 years), I learned that she had some unusual skills. One of which was a “Dr Doolittle” like affinity with animals. In fact, in our verbal prenuptial contract was a clause that I had to agree to living with cats. Siamese cats to be specific. We had a succession of these intelligent, bossy animals over several decades. Much like SWMBO. I quite liked them. They just tolerated me. We also had beagles. And later, cavalier spaniels. The cats dominated the dogs.
Then, about 10 years ago, the last beagle and cavalier died, and we decided that we were at an age where we would like to do some travelling without worrying about placement of the dogs and cats, and we would be pet free, apart from dog sitting and cat sitting the pets of our children from time to time.
A major factor in the decision to be pet free was that our house had become a visiting point for wild birds. In a hot summer, I had placed a water bowl high up out of reach of neighbours’ cats, and kept it full for the hot months. And SWMBO started placing seed rings for the visiting birds. I made the cats feel unwelcome by pelting them with rotten lemons. But they still managed to kill an occasional wild bird.
The water bowl was visited by scores of visiting birds every day, to drink and bathe. Sometimes I needed to refill it several times each day. And the seed rings were very popular. Magpies, sulfur crested cockatoos, ravens, rainbow lorikeets, galahs, currawongs, rosellas. SWMBO knew which seeds appealed to which bird varieties.
They were fascinating to watch. There were strict orders of precedence and pecking orders. We became aware that there were lookouts posted for when the seed rings were put out. A bird would squawk, then fly off, and return a few minutes later with his/her family. They even seemed to recognise my wife’s car arriving. They certainly recognised SWMBO herself.
Our favourites were the cockatoos. They would arrive singly, in recognisable family groups, and in flocks of 20-50. They would bring their chicks. And when the chicks had their own offspring, they would bring them. They tolerated me walking past, closer than a meter, as long as I did not look at them. SWMBO they totally trusted, taking food handed to them. The magpies were also much loved. They feel totally at home, sometimes walking into our kitchen if the door is open.
This one sits at our living room window, eyeing us until we react.
If the water bowl was empty the cockatoos would squawk, tip it over, or push it off the balcony.
I counted 25 cockatoos in this group. They take it in turns to access the seed ring.
Then yesterday, their pushy attitude reached a new level.
I was inside working on the computer, and ignoring a cockatoo’s cries for attention. A seed ring ring had been put out a few days earlier, and we are cognisant of the need to be occasional suppliers of food, rather than a regular source.
Suddenly I heard a clatter of a metal water bowl hitting the concrete paving. The cockatoo had pushed it off the balcony table . I continued to ignore it. Some time later I heard another thud as something else was pushed off. I continued to ignore it. The squarks seemed to settle.
A couple of hours later I went out and saw the source of the thud……
I had not responded to the water bowl being turfed, so the little bugger decided to up the ante!The guilty culprit. Not at all concerned.
Stuart T has made a new valve chest gasket for the Fowler R3 traction engine. I will see him in a couple of days to pick it up. Meanwhile, a few days free, so I have started another home renovation project.
I installed this bath in our house about 45 years ago. A neighbour was renovating his bathroom and knowing of our fondness for antiques, he asked if we would like his old bath. Otherwise it was headed for the rubbish tip. It was cast iron, on lions paw feet. The taps were very large, and truly superb. They were mounted on a porcelain or ceramic shelf, which had the logo “Fin du Siecle” (“End of the century”) so it was probably manufactured in the 1890’s which was the period of my neighbour’s house. Unfortunately the surface of the ceramic shelf was badly crazed. The bath had many coats of paint. But it was huge, had an elegant shape, and we loved it.
My wife, SWMBO, spent many hours stripping off the many coats of paint, and sanding the surface smooth. I had the cast iron feet brass plated, we coated the brass surface with a lacquer to prevent tarnishing. I made new gaskets for the taps, and cut new washers from leather. The washers were also huge. The ceramic shelf was professionally sprayed with a bath resurfacing paint, and the “Fin du Siecle” logo was sadly covered (after photographs were taken).
It was so big that it would not fit through the bathroom doorway. But our bathroom renovation involved replastering a wall, so the very heavy bath was carried in through the opened wall by a much younger me, and a group of my then much younger friends. SWMBO says that our daughters learned to swim in that bath, it was so big.
The interior surface of the bath was professionally sprayed with a bath surface renewal paint, and that surface lasted about 15-20 years. Then it started to fail around the plug hole, with rust appearing, and gradually spreading. Then maybe a decade later the taps stopped functioning. I disassembled them, but they did not appear to be repairable with my skills at that time (pre metalworking). So I bypassed the antique taps and installed valves further back in the line.
We stopped using that bath, except for washing the dogs, which accelerated the surface deterioration. It really started to look disgusting, and earlier this year we made the decision to “fix up” the bathroom. That involved buying a new bath, repairing marble tiles, rebuilding the shower recess, replacing the shower screen, and getting the floor heating fixed.
But the first task was to remove the old bath.
Remembering how heavy it was, I was in no hurry to start the job. But a few days go we were visited by my son in law, who is Samoan, and incredibly fit. He is built like a rugby player. He noticed the large box containing the new bath, and offered to help remove the old one. So we did. I was not expecting to do this job just then, but the offer was too good to refuse, so we did.
Regrettably, it was impossible to remove the old bath intact, unless a large hole was made in a wall. So, I used a 9″ angle grinder to cut it into 3 pieces. The cast iron was about 8-10mm thick. A very dirty job. We wore safety glasses, ear muffs, and face masks. Even so it was a VERY dirty job. I had previously disconnected the taps and drain, removed the tap handles, drain, ceramic shelf, large lead drain plug, and lions feet.
The ceramic shelf, with logo and artwork painted over. Separate taps and outlet, and soap holders. Would have been the height of fashion in 1890’s.The 120+ year old bath looks sad without its tap handles, water spout and ceramic shelf, and getting cut up.
The two of us carried out the 3 pieces, and with some effort, lifted them onto the Landcruiser tray. My eldest daughter wanted the old bath for her garden, but now that it is in pieces has decided to take only the lions feet and the round end of the bath. I will store the other cast iron pieces in case I want to use the metal for a model.
2 pieces removed, one to go. The marble surfaces were protected with wooden boards and rubber mats. Some marble wall tiles had become loose, so were removed pending reattachment.I expect that this end of the bath will become a planter box for my daughter’s garden.
The cast iron dust is incredibly dirty, pervasive, and spread into nearby rooms.
I am happy that this difficult, dirty, heavy job is done.
But, I am sad that the grand, old, antique bath had to be destroyed to be removed. I feel like a Vandal.
Installed the rotation preventer yesterday. It stops rotation movements when the mill-drill worktable is raised and lowered.
The brackets and linear stage rails were bolted together after positioning the brackets on parallels on a machined surface table (from the now closed Ford factory).Then attached the assembly to the column by bolting together the halves of the brackets. A bit of adjusting of tensions to get the slide working smoothly on the rods, then bolted the linear stage to the gear enclosure with 2 more cap screws. The Metabo drill provides plenty of power through the worm and gear to raise and lower the heavy worktable, and the drill electronic speed control provides excellent control.
When everything was tightened, No worktable rotation movement at all was detectable, even when pushing on it, and the raising and lowering movements were unaffected. It is a rigid setup.
So, how accurately is the position maintained during raising and lowering?
A laser pointer was set on a millimeter scale. Not super accurate, I agree, but should give some indication. The laser is only 40-50mm from the scale.
Then lowered the worktable about 300mm.
The laser dot is bigger at this distance but it is still centered on the same point.
This setup feels really rigid, and I feel pretty sure that it will work well.
Discounting the cost of the incorrect specifications of the first laser cut parts, the overall cost was about $AUD400.
The traction engine crankshaft is installed, and just needs valve timing for the job to be completed. But I am taking a break from that project to get back to the mill drill attachment to prevent work table position changes when adjusting the table height.
I had bought a used linear stage mechanism…..about the same cost as 2 pieces of ground 30mm shaft, but it included the precision bearings in the stage table.
… and had some 20mm mild steel plate laser cut to attach the linear stage rods and table to the mill drill….
…… but unfortunately got one of the dimensions wrong and had to scrap the laser cut cut brackets, remeasure them, redraw them, and order more laser cut parts. An expensive mistake.
Anyway, the new parts were collected yesterday, and today I started to machine them.
I used the opportunity to redesign the brackets to reduce their weight, as well fixing the mistake. The crucial dimensions are the diameters of the 3 circular holes, and the distance between the large hole (for the column) and the two small ones (for the linear stage rods). I specified the diameters to be 1 mm smaller than final dimensions to allow for final machining, to adjust for laser draught and laser cutting marks.
I was pleasantly surprised by the quality and accuracy of the laser cutting. There was no visible variation from 90 degrees cutting angle, and the dimensions were probably accurate enough to use with just a minimum of cleaning up. But I had to remove the 1mm machining allowance from the 3 holes.
The setup on my 28 year old CNC mill. Note the spray coolant. 7mm depth of cut, 0.5mm side cut. All straight forward.
Then I milled some deep pockets for the cap screw heads, and drilled some 5mm very deep holes ready for cutting the screw threads for the 6mm cap screws.
Then disaster! Just finishing drilling the final 90mm deep hole, and the drill bit broke. With no part of the drill protruding. I had used coolant, and frequent withdrawals to clear swarf, but it was a long series drill bit, and I must have pushed it just a bit too hard. I could see the broken end of the bit about 20mm down the blind hole. No hope of getting it out that way…. too deep to weld and I do not have access to an EDM machine.
The big hole was to be cut into halves, then bolted together around the mill drill column.
Hmm, I wondered if I could bandsaw almost to the embedded high speed steel drill bit from 4 directions, without actually cutting into it then snap the steel halves apart, and maybe grab a protruding part of the drill bit? Worth a try? (If that did not work I might be able to break up the drill bit with an old carbide milling cutter. That has worked for me previously.)
Nothing to lose, and I could think of no other solutions, so that is what I did. Here I am cutting the part where the broken drill bit is in the lower part of the workpiece. I cut almost to the drill bit from 4 directions. I could have used an ultra thin cutting disk in an angle grinder, but decided to start with the bandsaw. Didn’t end up using an angle grinder.
Then held the piece in a strong vice, and ever so gently bent the pieces back and forth until I felt them snap apart.
Inspected the drill bit ends. The end in the through hole just fell out. In the blind hole there was a protrusion about 3 or 4mm long which I was able to grab with pliers. And glory be, I felt it move, and gently pulled and rotated and it came out! Lucky!
Then tested the parts on the mill drill column….
PERFECT FIT! Both halves clicked into position. (second half not shown in this photo). The rectangular cutout fits over the table elevating rack.
Then spent some time tapping the holes for the M6 cap screws. All good.
I need to drill, counterbore and tap holes in a similar fashion for the 30mm rods, but they should be much less deep (only 50mm). Then to repeat the entire exercise for the other bracket. Next workshop session. Then to set up the apparatus and measure how effective it is. It had better work. Next installment in a few days time.
Yes. As usual, this project has taken at least twice as long as I had planned.
But, the making of the crankshaft has finished, and I have started to install it in the traction engine.
I installed the valve eccentrics, approximately in their correct positions. I had marked the eccentrics according to their position on the old crankshaft. The exact timing positions will be determined when everything is installed.
The crankshaft was placed in the main bearings. I had made the crankshaft with the bearing spacings according to the original plans. Then realized that the original maker had varied some of the dimensions, including the distance between main bearings. So I needed to gain approx 2mm between the main bearings. I achieved that by taking some width off one of the gears on the lathe.
Today, I started to fit the big end bearings. I had deliberately made the big end journals 0.1-0.2mm bigger than the old ones, knowing that I would have to increase the diameter of the big end bearings.
The 3 jaw chuck is holding a smaller independent 4 jaw (because I did not have a suitable backing plate for the small 4 jaw. And I needed a small 4 jaw so the bearing halves would seat on it.). The big end bearing is held in its engine housing, and the original bearing hole was clocked in the 4 jaw as accurately as possible, after tapping it against the jaws with a light hammer. Then the bearing was turned to the slightly larger diameter.
The crankshaft with the main bearings and big end bearings tightened. The eccentric rods are held out of the way with aluminium wire. The shaft turns but it is very tight, and will need further freeing. I have used some “Gumption” but it needs a bit more. Maybe running the engine on compressed air will free it up.
A quick test with the flywheel in position looked promising in terms of run out.
When turning the big end journals the supporting block for each crank had to be heated to release the Loctite and remove the block, then re-glued in place after the journal was finished.
Then the mainshaft itself was turned.
But first the centres for the big ends were cut off, after making sure that the journals were totally finished!
In this instance I used the horizontal drop bandsaw, because I have not yet replaced the damaged blade on the vertical bandsaw. There is a piece of steel clamped in the vice, and the weight of the workpiece is sufficient to keep it in place during the sawing.
As you can see I used a flood coolant-lubricant. Here getting the dimensions close to final using a tungsten insert tool, at 235 RPM. At that speed balance weights were not required. Depth of cut was 0.5mm, and frequent stops for measurements, so it was a time consuming process. And to disassemble and clean the cross slide DRO glass scale. I reversed the workpiece where required to cut towards the headstock. I still do not know exactly what the steel grade is, but whatever, I had several changes of inserts as they lost their edge.
The final machining step (I hope), was to mill the keyway grooves. That took another 6 hours.
The CNC rotary table was very useful for setting the angles, and locking the shaft in position, on the mill. Two 6mm carbide endmills were required to cut the 10 keyways. Here I used a spray coolant, powered with compressed air. A little less messy than the flood coolant.
The crankshaft is almost ready to be installed in the traction engine. The support blocks to be removed finally. The shaft ends to be chamfered. And the crank weights to be drilled, tapped and bolted in place.
I had marked the eccentrics positions before the original disassembly, and here I have installed them approximately in the same positions on the new crankshaft. Of course they will require small adjustments later. The gears slide smoothly on their splines.
Doubtless there will be installation issues. The old crankshaft deviated from the plans in quite a few respects, and sometimes I was unsure whether to copy the old crankshaft, or to follow the plans. “Copy the old crankshaft” was the general advice, but there were some obvious discrepancies which had to be addressed. I can only hope that I have made correct decisions.
During the turning of the big end journals yesterday, the digital display on the lathe stopped showing the cross slide position. So I completed the task relying on micrometer measurements. A more traditional method, but not totally in my comfort zone, being more used to the digital readout method.
Today I investigated to cause of the failure. First I switched the cross slide and longitudinal feed cables on the display unit to see whether the fault was in the sensor component/cable or the display itself. The fault was clearly in the sensor component/cable. These do fail occasionally, and are not horrendously expensive to replace, but waiting for a replacement was going to be annoying since I am in the middle of a very interesting job (making a crankshaft).
Hmm. I wonder if it is a fault which I can fix? I have never taken one of the units apart previously. And it is probably full of springs and bearings as well as a fragile graduated glass slide. But, nothing to lose. So here goes nothing…
Unbolting the scale from the lathe was straightforward, since I had originally installed it. But it was quite a few years ago.
Moved the sensor manually with it switched on. Still no movement on the display.
So I disassembled it.
Unscrewed the end block, and gingerly separated it from the aluminium case.
Then pulled out the rubber seals (the blue strips in the following photo).
The glass slide components, after wiping clean.
Then pulled out the unit with the electronics and the sensor. This was where I was expecting small bits to spring out and go flying across the workshop, lost forever. But no. It came out as a unit.
The board, glass scale, bearings etc were all covered with coolant and tiny chips!
How to clean them? I used compressed air.
Then wiped the glass graduated scale and protective blue seals with a clean microfibre cloth.
Reassembled the unit. Not difficult.
Switched it on.
Hallelujah! It worked!
Note to self. The sensor unit needs to be made coolant proof.
Finish turned the big end journals today. I decided to make them slightly bigger than the original shaft, because there was a measured deficiency of approximately 0.1mm – 0.15mm (? wear, ? manufacturing error) between the original shaft and the original split bearings.
I had rough milled one of the big end journals a couple of days ago, and Loctited a block into the crank slot of the other big end. I decided to finish turn that journal first, then to remove the loctited block and glue it into the finished crank slot, before rough milling then finish turning the second big end journal. If you follow me.
That all took another half day. And, I experienced my first significant (but not fatal) stuff up in the job.
Copious coolant, 135rpm. Of course the workpiece is centered on the big end journal. Here the tool is approaching the journal to be machined. The packing piece is glued into the other crank slot, and will remain there until the journal being machined is totally finished.
After finishing the first journal and changing the location of the packing piece the second journal was roughed out on the mill. I was much more confident about this method by now, and was more aggressive with the cuts. Used coolant throughout, and the cutter was in good shape at the end. I roughed the diameter to within 1 mm of the final dimension to reduce the time for finish turning. Note the use of my shop made clamp to reduce backlash and vibration. That worked much better than the previous soft wire method.
When I was happy that the journals were finished, I glued in a second packing block, centered the shaft, and turned the curved outside shape on the crank flanges.
As you can see, there is a lot more swarf to be made yet.
Oh yes. The stuffup. After one side of the first journal was turned the insert was blunted, so I rotated the insert. But unfortunately dropped it and chipped it, so it was replaced with a new one. My error was that I did not notice that the tip radius of the new insert was different… 0.8mm radius rather than the original which was larger and made a nice fillet at the join (see above photo). The new insert made a much sharper join, still with a radius, but much sharper. Not fatal, but not ideal.
In the next session I will recheck all of the big end journal measurements. If all are good I will cut off the side flanges at the ends of the shaft, removing those centers for ever.
I will see if my fixed lathe steady will fit into the middle gap between the cranks. If it fits, I will take a smooth light lathe cut of that section and install the steady. Then finish turn both outside sections of the mainshaft. Then move the fixed lathe steady to one of those outside ends, and finish turn the central section. The central section is where the eccentrics are located.
If the fixed steady does not fit in the middle section I will finish turn that section first, after installing the fixed steady on the longest outside section of the mainshaft.
Those possibilities are to keep the mainshaft as rigid as possible during all of those turning steps. (that list is more for my benefit than yours, dear reader).
p.s. So far, there has been no discernable distortion of the workpiece despite removal of over 20kg of swarf. That has been assessed on a granite surface plate, after filing all of the machined edges of all metal tags and lips.
Not finished yet, but the end is in sight. Maybe 2 or 3 more workshop sessions.
Today I roughed out one of the crank journals. I had hoped to do both of them, but had some problems to solve.
Normally big end journals are turned on the lathe. With this crankshaft, the lathe tool “stickout” is over 40mm. And the section is initially square, so the turning would be VERY interrupted. So I decided to try a new method (for me), of converting the square section steel to round section on the MILL. This is the setup…
On the left is a rotary table, powered by a stepper motor. On the right is the tailstock. The heights were adjusted using a height gauge. The Y position was determined with a clock gauge. The vertical mill has a 12mm carbide end mill running at 2000prm. Depth of cut initially 0.5mm. Rotary table is set to run for one complete turn. The stickout of the endmill is about 45mm, to just clear the flanges… the weakest link. I broke another endmill, so reduced the rotation speed, and added spray lubricant. Even so, it was not a secure setup. It improved after I replaced the ziptie with soft wire.
The end result, a “roughing in”, was not too bad. Since the end mill was centered over the journal, then moved to the lateral extents. each cut bulges slightly in the middle. In retrospect I could have flattened the cylinder by creating a final spiral. But since it will all be finished with a lathe cutter, that is irrelevant.
Note the Loctited spacer in the other crank space. I started the same process on that big end journal, spotted the difference, and aborted the process just in time.(!).
So I transferred the crankshaft to the lathe…. and discovered that the toolpost was too wide to permit turning due to collision with the shaft end block.
Here is the turning setup. If the toolpost looks a bit odd, I have removed about 10mm from the near side, to allow clearance. This was a damaged toolpost, so I had no hesitation in modifying it. Note the extreme tool stickout. That is why I wanted to NOT have interrupted turning. So I have not yet tried the setup, but I think that it will work. The journal is currently about 38mm diameter. It needs to be reduced to approx 26mm. Stuart Tankard made this tool, and its left hand companion. Thanks for the loan Stuart! I will proceed gently. And use flood coolant-lubricant.
So, again, not much to show for 5 hours in the workshop! But progress is happening. And this is a fascinating job!
Incidentally, the rotary table stepper motor became too hot to touch during the milling. But it did not falter. Very impressed. I think that it would be possible to do the entire journal shaping on the mill. Maybe next time.
Another workshop session. About 5 hours today. That is about my limit before I need to put my feet up.
Today I hacked into the solid heavy strong shaft, to form the crank web slots.
This is the setup. The workpiece was held in the mill vice. The end pieces were levelled using a height gauge, and supported with adjustable screw jacks.
The carbide cutter was 12.7mm diameter, and flood coolant was used. Each cut was 2.5mm deep.
The 2.5mm deep cuts were extended to 38.1mm. Then the slot was widened to 19.05mm using the same cutter, but taking 19mm depth per pass, and 1mm side cut per pass. The right hand slot is finished, and I used an old broken 3/4″ cutter shank to gauge the width. How did I break a 3/4″ solid tungsten cutter? I don’t remember and don’t intend to.Old and new line up pretty well. Actually mine are more accurate, according to the plans.Those deep slots will need to be packed when the big end journals are turned, and also when the mainshaft is finish turned. Otherwise tailstock pressure could distort the crankshaft.
So parted off x2 19mm buttons from some 36mm shaft. They slide into the gaps, and will be loctited in place when necessary.
Finally for today I measured the big end bearings, main bearings, eccentric holes, and mechanical water pump eccentric hole. The bearing holes were all approximately 0.2mm larger than the old shaft size, probably due to wear. They are all close to round, rather than oval. So Intend to machine the new shaft to match the largest diameter of the bearings. If necessary I will ream the old bearings to match the new shaft with a circular shape.
I am a bit apprehensive about turning the big end journals because the work piece will be severely unbalanced. Obviously I will install some balancing weights on the lathe face plate, but then there is the situation of the long stick out length of the turning tool, about 40mm. I am pondering the possibility of using the motorised CNC rotary table to very slowly rotate the workpiece, while converting the square sections to cylinders on the vertical mill. Then finishing the journals on the lathe. Hmm. Might just work.
This is the moment when I allow myself to envy the owners of 5 axis CNC mills, in which a crankshaft is made in the duration of a YouTube video, with perfect results, no mess, just a bit of expert CNC programming. But then… if it was that easy, everyone would be doing it.
You might be wondering why I am posting these updates after each workshop session. Partly it is so the day’s activities are recorded while still fresh in my mind. But it is also my method of keeping a diary, for possible future reference, in case I ever have to make another crankshaft (like for another triple expansion steam engine?).
I decided, after advice from several readers, to rough turn the mainshaft.
But first, just in case you were wondering, the kitchen entry stairs are finished, except for a bit of painting.
But just in case kitchen stairs are not your thing, back to the Fowler R3 traction engine crankshaft ….
Today I rough turned the mainshaft.
First I tested and adjusted the tailstock offset.
My method of adjusting tailstock set over is to turn disks at the ends of a 300mm bar between centers, with a very sharp tool, taking fine cuts, and measuring the diameters. Then adjusting the set over and taking further cuts until both diameters are equal.
Then mounted the crankshaft blank between pre-drilled centres…
And turning towards the headstock. This was interrupted turning +++. I took 1mm off the diameter, then as I became adjusted to the machine gun rat-a – tat-tat, gradually increased the depth of cut to 1mm, with a spindle RPM of 175/min. Later I added coolant. Note, I used a ball bearing tailstock centre for the rough turning. I will use a solid centre for the finish diameters.
Then turned the workpiece around and using the same DRO settings, did the other ends towards the headstock. Including the faces of the cranks.
I was not too fussed about actual dimensions. They were roughing cuts, and at 38mm diameter there is plenty of extra material. It should be much smoother machining to reduce the diameters of the cylinders, compared to rounding the square sections.
After getting quite a few opinions about stress relieving the workpiece, after all of this machining, I have decided to take the workpiece up to 600deg c, for 1.5 hours, then slowly cool. Probably unnecessary, since it is black steel, but it can’t hurt. Then I will do the final dimension turning.
p.s. about a week later. No detectable movement despite a lot more material removed. And some further expert advice that heat treatment might actually cause problems. So, given the controversy I have decided to do nothing. ie. No heat treatment.
Not a lot more to show after today’s 5 hour workshop session, but the debulking with the bandsaw and mill is complete. The 26.5kg bar now weighs just over 7kg.
I started to bandsaw the remaining 2 blocks, and was just finishing a long cut when the sawing sound abruptly changed and the cutting stopped. WTF? Examination showed that the blade teeth were still sharp, but the teeth set on one side was gone. I think that there must have been a hard inclusion in the steel which stripped the side set. Whatever, that blade is stuffed. To make matters worse, I did not have a replacement on hand.
So, I had to revert to milling to remove the waste blocks. Just to reiterate, the blocks are 38.1mm x 38.1mm x 180mm so it was a lot of swarf again. But I am now using flood coolant, so the swarf was not red hot, and the 12.7mm carbide cutter survived intact. I was reminded why I normally avoid coolant however. It is VERY messy.
And it took a couple of hours so I reckon that I earned this one.
The remainder of the session was occupied by measuring and marking for the crank cut-outs.
Almost every surface of that solid bar will disappear when the turning in the lathe is done. The only surfaces which remain will be the bar ends, and the square surfaces where the counterweights will be attached, and they will not be visible.
The next step.
Do I cut out the crank slots, or do I rough turn the mainshaft? If I cut out the crank slots then I would install some packing blocks, then turn the mainshaft. I cannot see a significant advantage in either next step. Any thoughts?
Yesterday I showed my model engineering group GSMEE, the bare old crankshaft, and the milled and marked lump of steel from which I am gradually removing all steel which is not crankshaft, and turning it into hot, sharp tiger snake repellant, I mean swarf.
“why don’t you just fix the old one?” (I tried. Unsuccessfully)
“why don’t you TIG weld the joins in the old one?” (possible, but Nah! It would distort, and would require finish turning, and I would probably be unable to use the existing gears, eccentrics, and big ends).
“You are going to get a lot more swarf”. (Yep!)
“What are the crosses for?” (So I know which bits to remove)
And some helpful suggestions….
“Cramp the steel vertically on the CNC mill, and drill the centers using CNC movements” (yep!)
“Machine the journals a bit oversize, and re-machine the bronze bearings because they will be worn, and a bit oval” (yep!)
“Turn between centres. Use a solid tailstock centre, not a bearing type” (Yep!)
“Turn the journals toward the headstock, and reverse the workpiece to complete the other side” (yep!)
And, considerable skepticism that the job would be completed successfully. (Understandable. It IS a challenge. But so far so good).
Today another half day workshop session. About 5 hours.
First task was to center drill the turning centers for the mainshaft and the big end journals. I marked the positions on a surface plate, using a height gauge, but the actual drilling using a center drill bit was determined by cramping the workpiece to a large angle plate, establishing a master face, and using CNC to locate the drilling positions. I was pleased to note that the CNC positions lined up pretty precisely with my measured positions. Then turned over the workpiece, cramping the same face to the angle plate, re-established zero X and Y positions , and drilled the other end. Those center drilled holes will determine the axes for the mainshaft and big ends, which are the essential reference points.Deeply drilled holes for some heavy, interrupted turning sessions.
But before the turning there is a substantial amount of steel to be removed by other means.
“Other means”.
First I tried milling, using sharp carbide end mills 12mm diameter. After I had broken 2 newish end mills, I thought about other means.
First, I used a bandsaw to make deep cuts. That steel is 38.1mm thick, and the cut is 38mm long. That is the thickest steel that I have ever cut with a bandsaw. I was REALLY surprised how quickly the cuts were made. Each one took 70-90 seconds.
Then I thought about using the bandsaw to make the long cuts, up to 200mm long, through 38.1mm steel. But the bandsaw blade was 25.4mm wide, so I chose to make a milling slot 25.4mm wide to allow access of the bandsaw blade. In the process I broke a HSS then a solid carbide 12.7mm cutter. Expensive.
A bandsaw cut 200mm long, in 38.1mm thick steel. It took 7.5 minutes. Surprisingly quick and effective! But cutting the slot was problematic… broke two cutters.So, for next one, I just used the bandsaw, making two angled cuts to remove 90% of the waste, then milling the hump out. That was easy. And quick! Way to go!.After the tidy up milling. That is half of the debulking process. Another half to be done tomorrow. Already the lump of steel is a lot lighter. Currently 10.5kg. The old crankshaft weighs 3.3kg, so still a lot of material to be removed. Just a reminder that the original weight was 26.5kg!
SO. I have formed an opinion about removing waste metal. BANDSAWING BEATS MILLING, HANDS DOWN! (but for finishing, milling wins.)
Well, actually it was a re-certification, for 3 boilers. The 1:4 traction engine has a 7″ diameter boiler, with a maximum pressure of 100 psi. and is coal-wood fired. The vertical test boiler is 6″ diameter, rated to 100 psi, and is gas fired. And the Trevithick dredger engine at 1:8 scale, is rated to 40 psi. Although it was designed to be fired with coal or wood, it is also gas fired. Mostly at exhibitions it uses steam produced by an external boiler, but the boiler in the model engine acts as a receiver for the external steam, so it also has to be certified to be run in public.
During the years of the Covid lockdowns none of these boilers were used much, and they were all out of certification. So with life returning slowly to normal, and exhibitions planned for 2023, I contacted our club’s boiler inspector, and arrangements were made. Since there were 3 boilers involved, and 2 other members of our club wished to speak to the inspector about their current builds, he offered to come to Geelong, which was incredibly helpful.
As preparation for the inspection I ran each boiler to make sure that all was in order.
I have previously described the problems found with the traction engine. Various water and steam leaks were fixed, and the crankshaft repaired, although a more permanent crankshaft replacement is underway. The boiler inspector was really only concerned with the boiler itself, the water pumps, the sight gauge, and the safety valves. Two actual tests were performed. The boiler was filled with water, then the hand pump was used to hold the pressure at 20% above working pressure i.e. approx 125 psi. The boiler was checked for leaks and distortions. Not surprisingly none were found. Then the water level was drained to normal, the fire was lit, and steam pressure increased to 100 psi. The fire was encouraged to burn as fiercely as possible, using the funnel blower, and later the steam blower. That was to make sure that the safety valves were functioning adequately, and at the correct pressure.
Then the vertical test boiler underwent the same procedures, but with a gas burner.
And the same for the Trevithick dredger engine, also with a gas burner.
All of the boilers passed the tests, and certificates were issued, for 4 years. Phew!
However, the big issue, the Elephant In The Room, is that the rules for small steam powered engines, trains, traction engines, which are fueled by gas have changed. In future all gas fittings have to be installed by licensed gas fitters. All gas fittings have to be purchased, approved and stamped, not made by the model maker. And currently, NO gas fitters in Victoria, and possibly any other Australian state, have been willing to be involved with engines, trains etc. which have been made by model engineers. Even installing gas burners which are sold for barbeques, camp stoves etc will not be permitted to be used in public exhibitions of steam engines, locomotives etc.
Which means that no gas fired model steam engines will be able to be run in public. It remains to be determined what the situation will be with gas fired internal combustion engines.
It should be stated that the new rules are under intense scrutiny and discussion. There is some hope that common sense and sanity will be applied. Or the current nanny state, Occupational Health and Safety nonsense will be applied to its fullest extent of stupidity. We can only hope that this will not be the end of a fascinating, stimulating, entertaining, and educational hobby.
Boys of various ages having fun on the R3 Fowler 1:4 traction engine. White shirt unwise when driving a steam engine. Photo taken 2019.6″ vertical test boiler with Southworth pump, is sometimes used to power the triple expansion model steam engine.
And the 1:8 scale model Trevithick dredger engine. The cylinder is inside the boiler!
P.S. In case you were wondering, the round column mill modification is still underway. Currently waiting for the column brackets to be cut by the laser cutter.
The first step was deciding which grade of steel to use, and the size and section of steel.
I have made several crankshafts, but only one was from solid steel. The others were all from pieces which were joined with pins and Loctite. And all of them were substantially smaller than the traction engine crankshaft. The solid steel crankshaft was for the model triple expansion steam engine. It had 3 cranks, so was a balanced design. I turned it from stainless steel.
The traction engine crankshaft has 2 cranks, at 90 degrees, so is not a balanced design. It turns relatively slowly, and the balance is provided somewhat by balance weights which are attached later.
I was advised to not use bright steel because of a tendency to change shape when machined, due to relieving internal stresses as material is removed. So I contacted several steel local suppliers about purchasing some black steel solid rod or square section.
The three small circles and black rounded rectangles are an end view of the crankshaft
The red circle with a diameter of 114.3mm is the minimum size of round bar stock if the crankshaft was turned with the mainshaft centralised.
The red circle with a diameter of 107.8mm is the minimum size of round bar stock if all 3 centres just fit within the bar.
If square section stock is used the minimum size is 76.2mm x 76.2mm.
In all cases the length of stock is 416mm.
Since steel bar is sold mainly by weight and grade, I looked for a supplier of square section black bar.
But square section black bar has radiused corners, as in the shape on the left. So, to end up with 76.2 x 76.2mm square section I needed to use 90x90mm with the radiused corners. Long story shortened (mercifully, if you are reading this), I found an engineering works locally who was prepared to cut off a 420mm length, shown in a photo in the previous post. It is heavy!
Next steps will be to mill the ends to 416mm, and 2 long faces to a sharp corner. Then to mark and centre drill the centres for the mainshaft and the big ends (the three small black circles in the diagram above). That will be today’s task.
Later that day…..
Squaring the ends of the 90x90mm lump of steel. Hmmm.. those radiused edges could be an issue…Taking off 1mm per pass with a tungsten tipped milling cutter.When the corners were squared, my 90x90mm bar just ended up 76.2 x 76.2mm. I always mark the waste with a cross. Don’t ask me why.The end result of an afternoon’s machining. That bar is too hot to handle. I will measure it accurately tomorrow.Oh. And a bucket of swarf after a quick clean up. A lot more to come.
In a previous post I explained how I replaced a broken roll pin in a fabricated traction engine crankshaft. The repaired crankshaft worked well enough for the renewal of the boiler certification, but I suspect that one of more of the other roll pins is also damaged.
But!….
… there is still a flywheel wobble of about 1mm at the rim. 1mm does not sound much, but it looks horrible. So I have decided to make a new crankshaft. Using a single piece of steel.
The crank-shaft is at the right of the photo, beneath the big ends, eccentrics and main bearings.
For the third time in a couple of weeks I removed the crankshaft from the engine. The first time took me more than 4 hours. Second time was quicker. Today it took me only 93 minutes, including the time wasted looking for small open enders.
And meanwhile I bought a chunk of steel big enough to carve into a replacement crankshaft….
That lump of black steel is 90 x 90 x 420mm. It weighs 26kg! The faulty crankshaft to be replaced in front. The gear and the eccentrics will be removed in the next workshop session. And the original plans of the crankshaft at rear.
The crank-shaft has two cranks, at 90 degrees from each other. The shaft itself is about 26mm diameter.
My plan is to use the milling machine to remove most of the waste, then to finish the accurate diameters on the lathe, turning between eccentric centres.
It is apparent, looking at the size of the bar, that most of it will end up as swarf. Oh well. On the floor it will keep the tigers out of the workshop.
I purchased this mill-drill quite a few years ago, and generally it has performed well. 6 spindle speeds, morse 4 taper, 3 auto feed speeds. I installed an X-Y table, a 6″ Vertex vice and the digital quill movement scale. All good.
But, the crank handle height adjustment for the head, and the table were both very heavy to use. And they are getting heavier as they get older.
As you can see, I tidied up the area especially for the photo.
So I installed a motorised raise and lowering mechanism for the work table. That was detailed in the post “Motorising a Mill Drill Table” Feb 2021. For a variable speed, reversing motor, I used an old Metabo drill, which has heaps of power for the job. I removed the crank handle, and installed a worm and gear in a 100x100x150mm box. It has worked very well, although I probably geared down too much, because even with the drill at full speed, it is slowish to raise and lower the heavy table.
BUT. The round column is very frustrating. When changing the height of the work table the XY position is not maintained, and that is a real pain when doing multiple tasks in a fixed XY position.
I tried attaching a laser light projected onto a vertical line on a nearby wall, and that worked in a fashion, but not reliably.
Then I used the gear rack to keep the table in a fixed vertical position, but that was also unsatisfactory, because the rack would flex and the position was not accurate enough.
So, I should have NOT purchased a round column mill drill to start with. And I would NEVER do so again. But I have put up with the limitation and have continued to think about possible fixes.
Then I saw this on Ebay. And thought. “I have a use for this!”
It is a linear stage. The 30mm polished steel rods are 800mm long, and the threaded block runs on precisely machined bushes, presumably bronze. The winding handle, 16mm x 2mm threaded rod, and revolution counter are of excellent quality, but will not be used. The item appears to have had little use. There were some extra bits attached which I will not use.
And here it is cramped into the position where it will be used…..
The Metabo drill is removeable, but basically lives in that position. The worm is visible in the photo. Normally the worm and gear casing has a metal cover.
I will make brackets to attach the bars to the round column in this position. I decided to attach the round bars rather than the end blocks to the brackets. The central block will be bolted to the worm and gear housing. I am confident that this setup will stop the work table from changing XY position when the height position is changed. It should not get in the way of drilling operations.
Drawing of the brackets. I intend to make them from some 20mm thick mild steel which I found in my workshop. I was hoping to get the brackets laser cut from aluminium, but was informed that there is a limit of 10mm with that metal. They could cut 20mm of steel, but I would need to add a machining and perpendicularity allowance of say 1mm. Still thinking about that possibility. Might be simpler to just mill the brackets myself. It is 352mm X 177mm X 20mm.
I will post some photos when it is finished. And some measurements of the rigidity of the setup.
The lovely 1:4 scale Fowler traction engine which I bought in 2017 has had little use in the past 3 years, so I have decided to sell it. The lack of use was mainly due to Covid shut down of steam meets and exhibitions. While Covid restrictions have ceased, my interests have changed, and I now prefer to concentrate on smaller, stationary steam engines.
But first I needed to renew the boiler certification. The boiler is constructed from 4mm thick copper, silver soldered, and was made by an experienced engineer, so I do not expect any significant problems with the re-certification. Just to be sure, I ran the engine on compressed air. Immediately I noticed that the flywheel was rotating more slowly than the crankshaft. The cause was a sheared pin which joins two segments of the crankshaft.
The flywheel has always had a slight wobble, but now it was more pronounced. Obviously the crankshaft needed to be repaired or replaced. Initially I hoped that all that would be required was a new pin. It was a 1/8″ roll pin, and I hoped that I could tap it out and simply replace it.
I have the original construction plans for the engine, and those plans recommend a solid crankshaft in the interests of longevity. However, the original maker had chosen to make a built up crankshaft, securing the 8 joins with roll pins, and probably Loctite.
I contacted the original maker of the engine, an elderly gentleman living interstate, and we had a long and pleasant conversation. He was surprised that the crankshaft had failed, but did not recall the details of the construction. He strongly recommended removing the crankshaft from the engine and working on it in the workshop, a decision which I had already made.
Long story shortened. It took me 4 hours to remove the crankshaft, and on the workbench about 10 minutes to punch out the broken pin, and separate the crankshaft parts.
Crankshaft, big ends, eccentric rods, main bearings and flywheel removed.The crankshaft with undisturbed eccentrics, set up on 2 V blocks on a granite surface plate. With the 2 parts pushed together. But something was wrong. With the broken end clamped in the V block, the other end was held about a millimeter above the V block. WTF!
By this time the join had been cleaned with acetone, primed with Loctite 7471, and glued with Loctite Wicking 290. And reamed the hole to accept a number 1 taper pin.
So I checked the diameters of the mainshaft at both ends. 23.47mm at the broken end. 22.86 at the high end!!! Bugger. I should have checked before gluing. But why would the mainshaft have different end diameters???
Oh well! I decided, foolishly with hindsight, to reassemble the whole engine and see if the discrepancy was noticeable.
Next day, another 4 hours, and the reassembly was complete.
Rotated the flywheel. And it was horrible!! The flywheel runout was not “noticeable”. It was horrible!!
It had to be redone. Or do I just bite the bullet and make a new crankshaft?
I decided to redo the repair job, lining up the parts in the lathe.
Long story short again… teardown was much quicker this time. Experience counts.
This time I took a very light skim off the shaft and face using a very sharp cutter, to ensure that the ends and roughness were removed. Then held the broken shaft in a collet chuck which I know is very accurate. But found another problem. The shaft at the other end of the crankshaft had not only a smaller diameter, but was also at a slight angle axially, so I could not use the machined centre in the end of the shaft. So I set up the fixed lathe steady pictured, mounting it at the main bearing location. Trouble was that I had no accurate method of centering the steady. I described this setup to my engineering group, and was informed that I should have used a set up rod machined to the diameter of the end of the crankshaft, to set the position of the steady. Makes sense. My bad.
Oh well. I will reassemble the engine again. If it is again horrible, I will either do the whole job again, properly this time, OR MAKE A NEW CRANKSHAFT.
I have a feeling that I will be making a new crankshaft.
p.s. I allowed a day for the Loctite to cure, then deeply reamed the existing hole, and reinserted the taper pin in the enlarged tapered hole. This time the head was buried, but there should be enough purchase to remain intact.
Reassembled the engine, and turned it over to check the flywheel wobble.
I will not claim that it is perfect, but it is very close. I will not start making a new crankshaft just yet, but that is the next step if this repair is eventually unsatisfactory.
I decided to purchase a new lathe chuck, a 6 jaw, 160mm diameter, Chinese “Sanou”. I had watched Stefan Gotteswinter’s review of these, and based on his expert assessment, made an Ebay purchase. I found 2 Australian suppliers, and chose the cheapest one. All straight forward so far. Money paid using Paypal. A few days later, a call from the vendor, “very sorry, no stock remaining”. “But you have stock listed on your site”. “Very sorry, all gone, do you want me to order more from China.” Oh well. No real rush. “OK, yes I will wait”. But then the first hint that maybe all was not as it appeared…. “Ignore the tracking number. I will contact you when it has arrived”. Hmm. That is strange. But I waited. And waited. Eventually, 6 weeks after the initial order, I requested a refund.
I had another call from the vendor. “Very sorry, there was a problem with the Chinese supplier. The prices of shipping have increased, and the Chinese supplier used the container space for another customer who had paid the higher cost, so your chuck in my shipment was not sent”. “And the cost of the chucks is higher”. Yes, we know that prices of everything are rising. But why did it require my request for a refund to elicit this rather convoluted and slightly unbelievable explanation. And why was I originally requested to not check the tracking number? And why did it take 6 weeks to be notified of all of this?
Anyway, I did receive my refund. But what if I had not followed up on the non delivery?
Case 2.
Another Ebay purchase. This time for a battery powered screw gun for sheet plaster, because SWMBO has asked me to hang the plaster in one of her project house renovations “and will save a lot of money if we do it ourselves.” Now, hanging plaster is not a favourite activity of mine. In fact it is on my list of activities for which I would always employ a tradesman. But “happy wife = happy life”. So I agreed, but used the occasion to purchase another tool. Yes, I do have a disease.
So, another Ebay purchase, Australian supplier of a good German brand which I always use for battery tools. Not cheap, but reliable, and my one and only complaint to the manufacturer (Metabo), many years ago, resulted in immediate and generous restitution. Order placed, Paypal payment. Within a few hours I received a receipt, and a tracking number for postage from interstate. Now that was quick postage! Very impressed. Or was that too quick?
3 weeks later, it still had not arrived. Postage services in Australia have been very variable lately. Sometimes items arrive in a day or two. Some turn up months later. Some never turn up. I checked the tracking number, and it appeared that the package had been received at the interstate postal depot. But no record since then.
So I contacted the vendor. Return message. “it appears that your package has gone missing.” “very sorry etc etc.” Immediate refund. So immediate, that I had to wonder. I was expecting the vendor to ask me to wait patiently a bit longer, to which request I would have agreed. Why the immediate refund?
Meanwhile I have gone cold on the idea of hanging plaster. I have not told SWMBO of this change of heart, and she does not read these posts. Or does she? I will get an answer to that question very soon I suspect.
There are so many scams about these days. Like most people, I seem to get at least one scam email per day, which I just delete immediately. I NEVER click on email attachments, unless I am certain of the sender’s identity and purpose, but even then I check first. And I NEVER buy anything advertised on Facebook, having been scammed twice there, with NO COMPENSATION from Facebook for running fake advertisements.
Both of the above cases happened in the past month. Case 1, where there was a tracking number supplied, but obviously no article actually posted, has made me very suspicious about tracking numbers providing proof of postage. Case 2 could be a genuine postage loss, but if my suspicion about tracking numbers is correct, then maybe it was a scam too.
Julius deWaal has drawn and published plans for model engines, most recently the Bolton/Bertinat plans for the triple expansion marine steam engine. The triple plans are available to download free of charge at ….https://modelengineeringwebsite.com/Bolton_Bertinat_1.html
I made a model triple using the Bolton plans and castings, several years ago.
Here is a recent photo of my model triple expansion engine operating on steam at the Royal Geelong Show. In the background is a full size version, which is a permanent, operating, attraction at the show. My model is 250mm long, 250mm high, and weighs about 10kg. It has a Stephenson reversing mechanism, and an exhaust steam condenser, both of which work.
It was a difficult build, taking me about 3 years, with a couple of sanity restoring long breaks during which I built other models. The build was detailed on this blog. To check the progress photos and descriptions do a search on “triple”.
I was very happy to finish the build, and ecstatic to see it working on compressed air, and then steam. When exhibited it always attracts a lot of attention, with its myriad of small moving components.
But, I was a bit unhappy, because it does include some errors. These were partly due to the suboptimal plans, and more so to my inexperience. The errors are not apparent to a casual observer, but I know that they are there. They do not interfere with the operation on steam. I had considered making another, bigger, triple, but always backed away, due to the time, complexity, and cost.
But a friend recently sent me a link to the new deWaal plans. The link is below the first picture, above. The new plans are metric, very detailed, and TWICE the size of the originals…. i.e. a model built to the deWaal specs would be 500mm long, 500mm high, and probably weigh around 40kg!
I must be a glutton for punishment, or a bit nuts, because I am seriously considering making another triple, using the deWaal plans and not buying castings but using bar stock. And maybe using some home made castings.
Click on the picture to see a short video of the Fowler R3 steaming away.
Dear Reader, if you follow my posts you will know that I had stopped posting on WordPress because I had exceeded the 13gB memory limit.
I have been copying old posts to medium.com, and posting new ones there. Today I was copying some more, and I happened to notice that my wordpress memory limit had increased. There had been no notification of an increase. Maybe it was a mistake. So I posted the above video as a test, and to my surprise it was accepted. So I contacted support to see if there had been a change of policy. No, no policy change. Apparently it was a bug. Could it have been someone being kind? I asked. Possibly, was the reply. Do you want it changed back? NO!! I screamed.
So I have a 10gB reprieve. Enough for several years at my rate of usage. May be temporary. Time will tell. Meanwhile I will recommence posting here on WordPress, as well as medium.com/@johnsmachines
Very few of my johnsmachines.wordpress readers have switched to medium.com, so I was seriously considering pulling the plug on all future posting. So this is a reprieve. You will have the choice of seeing my posts here on WordPress, or at Medium.
P.S. The traction engine, tender, kids cart, custom fitted trailer with winch, and ~200kg of steaming coal is for sale. Located near Geelong, Victoria, Australia. Best offer over $AUD20k. Certification will be renewed prior to sale. Kids not included.
If you are a regular reader of my posts, you should know that nothing new has appeared on this site for months, or will appear on this site. in the future. No more storage space and wordpress is not interested.
Too few of my readers have so far moved to the new site.
The posts on this site are being progressively moved to the new site, but this site will CLOSE TOTALLY in a month or two.
SO, if you have any interest in my future posts you should check out the new site. Otherwise, I will take the hint, and disappear without ceremony, altogether.
P.S. 2023. WordPress quietly increased my storage capacity not long after this post was posted, so johnsmachines.com is still going.
Note, Reading posts is free, but to leave comments/feedback, you need to register with medium.com. Registration is free. Do try the “listen” option. It is remarkably good! The only drawback to “listen” is that photograph captions are not read aloud.
At the next level, for $US50 per year you have unlimited access to the millions of posts on the site. I am exploring some of these.
It is not a particularly interesting post, but if the new provider is OK, that is where future posts will appear.
And… the result of an experiment which was successful.
Today was very warm in southern Australia, but I successfully made a brass part for a friend. It took a couple of hours to design, and then about 3-4 hours of machining to make. See later photo. It is a bracket to hold a water gauge on a full size boiler.
I came home, cooked dinner for my wife and myself. And we agreed that it was delicious.
The evening was still very warm, and very still. Stars just appearing.
I had some xmas present cigars, and I decided to light one up, outside on our verandah. It was the first one for 3 weeks.
Bliss.
So still, that the smoke rings travelled for 2-3 meters before dissolving.
What could be better? Ah… some Laphroaig single malt. Lovely peaty flavour.
And yes it was a magnificent duo.
And then I had a brainwave. Something I have never tried before.
I dipped the mouth end of the cigar into the Laphroaig for a a moment or two. It wet the end but just enough to transfer some flavour. And continued to draw.
Bloody superb!
The cigar lasted about 50 minutes. I continued the dipping every 10 minutes or so. What a discovery!
Probably reinvented the wheel, again, but I record the blissful result in case it is original.
If you like cigars, and whisky, try it. Otherwise, stay healthy and avoid both.
I will remove the wrappers tomorrow, and finish the butt in my Meerschaum pipe. Life is good.
8 years, ~900 posts. 13gB storage full. WordPress offers the solutions of buying a business package at 3 times the price, or deleting old posts to free up some space. I have removed almost all of my videos, with considerable reluctance, to make space to finish the posts about the Armstrong 110pr model cannon construction. However I still get comments from posts posted when I was a newbie, so I am not prepared to delete any more of them.
Just a thankyou to you, my reader. Questions, comments and communications from you are the grist for the mill of blog posters, and I am no exception. I have really enjoyed the journey. Feeling a bit sad, but I will resume my private diary entries, instead of venting my thoughts on johnsmachines.com
I had said that I would move johnsmachines.com to another platform, but now I am not so sure. Some repairs to my house are my next priority, and that will be too boring to blog. At this time I am not moved to start another model, but down the track, who knows?
I had saved the last little bit of storage space for the final photos of the Armstrong 110pr model cannon. Photos of the finished model follow.
The wooden carriage and traversing platform were stained with Japan black, then several coats of spray lacquer. It will be rubbed with steel wool and wood oil to give it a silky smooth finish.Focussing on the rear tangent sights. I might add some locking screws to the sight posts later, but then again, I might not.About 10º of elevation, provided by removing the quoin, and resting the barrel on the Smith’s elevating screw via the bed. Note the iron binders on the ends of the wooden slides.Top view. Queen Victoria’s cypher, the barrel weight (just over 4 tons), and the proving arrow. No touch hole on the model. This view also shows the asymmetric position of the sights, caused by canting the rear sights ~2º, and moving them 2mm to the left so they are equidistant from the bore at the nearest point.Almost horizontal with the Smith’s screw and quoin elevating the barrel. I will add some ropes and pulleys later. The right gunners’ platform needs to be pushed down a bit to sit in its correct position.From the front. The wheels only contact the slides when the rear is slightly levered up, to encourage moving the carriage from the recoil position back to the firing position. (not that this model can be fired. It has no touch hole). Also note the absence of trunnion caps, which was common in garrison guns.The model foresights were deliberately blunted to avoid observer injury; and left trunnion markings. EOC for Elswick Ordnance Company, barrel number 212, and 1862 the year the barrel was manufactured. Copied from an original Armstrong 110pr.
And that, dear reader, is that. Goodbye, best wishes, and thank you.
The 1861 Armstrong rifled breech loader cannon had foresights on the trunnion ring, and rear sights on the breech. The foresights had fixed lengths. The rear sights were adjustable and graduated for range. The foresights were vertical. The rear sights were canted at a 2º16″ angle to compensate for slight lateral deflection of the projectile caused by the rifling. The rear sights also had a lateral adjustment screw to compensate for movement of the target.
At 1:10 scale, the components of the sights were tiny, and I decided to not make the lateral compensating adjuster. But I did decide to incorporate the 2º angulation. That required the left and right rear sights to NOT be equidistant from the centre line of the barrel. The drilling of the barrel holes for the sight holders was consequently not straightforward, and I spent a couple of hours on the CAD drawing to work out the drilling positions, depths, angles etc. And then considerable time was spent setting up the barrel in the milling machine vise, so that the bore was horizontal, parallel with the mill table, and level when the foresights were drilled, and tilted 2º when the rear sights were drilled.
That took two full machining sessions over two days. I was not looking forward to it, knowing that a broken drill or other mishap would be catastrophic. In the event, it all worked out OK. Some pics…
1. The 2º canting of the rear sights was established with 8mm and 10mm thick parallels sitting on 1-2-3 blocks under the trunnions. There is an 18mm rod in the bore, sitting on the jack to hold the barrel horizontal. A 4mm end mill is creating a flat surface from which to start the drilling.
2. That is a 2mm drill bit, silver soldered to some pipe to give it some extra length. “Tension drilling” again.
3. Checking the lengths of the foresights.
4. The almost finished sights. Left rear holder needs to be shortened. And yes, the magnified photo does reveal a previously undetected superficial crack in the left weighted arm. Luckily I have a spare part if it breaks. I must have used too much force when I pressed in the driving pins.
This series of posts is almost complete. Making the 1:10 scale model Armstrong Breech Loading, Rifled cannon, 110pr* took almost a year, and these posts were originally published by johnsmachines.com in wordpress.com. Since I am intending to cancel my subscription to WordPress I have decided to transfer some of the 900 posts to this new, for me, site.
Further old posts will gradually be transferred. And some new ones will be appearing.
This is the lathe which was used to turn the 18.1″ guns of the IJN Yamato. (keep reading. Bismark comes later). The Yamato lathe was purchased by Japan in 1937 from Germany. Japan did not have the capability to make such a huge lathe. The only countries which did have that capability were Britain, USA, and Germany, and Japan did not want the British or Americans to know how big a battleship was being built. The weight of the Yamato (>70,000 tons) was not known to the allies until after WW2! It was the heaviest battleship ever constructed, and carried the biggest guns ever installed on a battleship.
1. Wagner lathe used to manufacture the Yamato and Musashi guns.
I assembled a plastic model of the Yamato earlier this year.
2. 1:350 scale Tamiya model.
….and showed my model engineering club.
Somehow the conversation involved the guns, the Yamato Museum, and the huge lathe which is being moved from its original factory, where it was in use until very recently, to the Yamato Museum.
A senior member of our group, who lives near Yallourn, Victoria, stated that the lathe which made the guns for the Bismarck was currently located in Yallourn, Victoria, Australia!!!
There was a collective dropping of members jaws. WHAT???? HOW??? It cannot be true!!
To cut the story short, further investigation by the member, confirmed that a very large Wagner lathe had been shipped to Australia, as a reparation after WW2. The lathe had been installed in the State Electricity Commission workshop to turn large generating armatures. The SEC workshop was now a private manufacturing factory, and the lathe was still there!!!
The managing director of the company was contacted, and a few weeks later 24 of our club members visited the factory with the tour being conducted by the owner-manager. The factory was fascinating, and the tour lasted over 2 hours, but I shall concentrate on the lathe.
3. This is our group, in front of the headstock, clearly displaying the Wagner Dortmund name plate. I am in there. The machines to the right are applying tungsten to the large roller seen, using a robotic arm and laser welding machine. The lady in the orange jacket is the member who told us about the lathe’s presence. 4. The 4 jaw chuck is 8’4″ diameter.
5. The lathe has 2 carriages. The toolpost is over 6′ high. The beds are covered while the tungsten coating is being applied.
6. The tailstock end of the bed, with 6 steadies. Unfortunately I could not find a serial number, but it was probably hidden behind other equipment.
The distance between centres for the lathe is 70’/20m, certainly big enough to have turned the Bismarck guns. The lathe OAL is 90′. The original tailstock and a section of bed was lost at sea in a storm during transportation to Oz. Replacements were found and installed.
Currently the lathe has a 50hp electric motor. It turns between 1 and 20rpm.
7. The factory covers 20,000m3. I could not get a decent camera view of the whole lathe. The headstock is to the left of this shot. This view is one end of one of the six factory bays.
So. That was a great day.
The factory owner manager is searching for documentation about the lathe, which is essential if the Bismarck association (and Tirpitz, and more than a few shore defense guns around France, Denmark, Norway) provenance is to be firmly established. The locals certainly believe that it IS the lathe which made the Bismarck guns. It is possibly true. The Yallourn lathe looks very similar to the Yamato lathe.
8. Bismarck
9. Tirpitz was the sister ship of Bismarck. Showing a ~18m long 15″ barrel without the breech.
Just one photo. me and my model triple expansion steam engine, running on steam, and the Armstrong 80 pr Muzzle loader, both entries eliciting a lot of spectator interest.
Maybe one more….
This is my model triple expansion steam engine, running on steam, against a background of a full size marine triple expansion engine, also running on steam! Cool eh?!
In the above photograph, taken I think of a 110pr Armstrong breech loader in Canada, of a Garrison mounted gun, there are several very interesting features. The Smith’s elevating screw for instance, and the remnants of the left hand breech tangent sight. But I am particularly looking at the flat surfaced item which is attached to the top of the breech. It took me some time to work out the function of the rather complex shaped item.
The breech block, which weighed 130lbs, had to be lifted out of the breech by two strong gunners to permit swabbing of the bore from the breech aperture (also visible in the photo), then loading of the next projectile and gunpowder bag, after which the breech block was lifted back into position and screwed tightly closed prior to the next firing.
Ah….. the flat topped attachment is where the breech block was placed while the swabbing and loading took place!
So I set about making the breech block rest (as I called it) for my model.
The rest looked complex and difficult to model. The inner surface had to fit the external surface of the breech, including two convex fillets. The external surface has to fit the breech block, without denting or otherwise damaging it despite its considerable weight and frequent manhandling. And there are holes for 6 attaching screws.
First I turned a disk in LG2 bronze. The interior surface fitted closely over the breech, including the convex fillets. I used a bullnose milling cutter to turn the fillets. Then the top surface using the scarey shell cutter. I handle this cutter with great care because it is razor sharp.Then CNC milled the shapes which hold the breech block securely…And finally drilled the screw holes and parted the fitting from the bronze disk. The under side.and the top side.Here the breech block rest is Loctited in position, ready for the screw holes to be drilled into the breech and the screws fitted.The breech block resting in place, ready for reloading.
Now, dear readers, I must inform you that I have only enough WordPress memory for another one or two posts and a few photographs.
The Armstrong 110pr breech loader cannon model project is almost finished.
The remaining parts, including the Smith’s elevating screw, carriage wheels, rope eye bolts and capstain were all described in the build of the Armstrong 80pr rifled muzzle loading model cannon, so I will not repeat those details for the 110 pr.
I will leave the remaining small memory for the assembled model of the 110 breech loader, in a few weeks time.
And since I will not delete any more old posts, that will be my final post. (unless WordPress changes their policy of not increasing memory limits. And I do not expect that to happen.)
In the final post I will notify you, my readers, of the site where I will post photos of future projects. Not quite yet decided, but it will NOT be WordPress.
My workshop uses a 6kw Phase Changer machine to convert the 2 phase supply to 3 phases, which is required by my CNC mill, DRO mill and big lathe.
When I turned it on 2 days ago, I was startled by a very loud “bang” and a puff of black smoke from the phase changer. And no power output, unsurprisingly. On opening up the machine I was pleased to note that the (very expensive) transformer looked intact. But one of the large capacitors looked a bit ragged.
1. I restarted the unit with my iPhone recording so I could show the manufacturer. The culprit is the second capacitor from the top. The replacement capacitor came yesterday.
So I have been limited to single phase equipment for the past 2 days. It did force me to finish some outstanding tasks….
2. ….Like making the traversing platform axle washers…
3. ….and making the tow bar….and finish installing the wheels.
and yesterday my colleague and friend Stuart T used his 30w fibre laser to engrave the manufacturer name, number, barrel weight, date, and Queen Victoria’s cypher.
4. Stuart and his laser. He reckons that it has been used more for my model cannons than his own work! The orange machine is a tiny CNC mill which Stuart made a few years ago.
5. The laser in action
6. The engraving as it first appears. Some polishing is required to remove the rectangle around the cypher and to sharpen the image outlines. The trunnion ring is still waiting for a cleanup after being heat shrink fitted.
30mm diameter, 11mm thick, a rail groove on the edge, circular divots on the faces. Simple!
But…
I decided to make them from stainless steel. And tonight I have multiple small cuts on my fingers to prove it.
Stainless steel is a bugger to machine. It requires slow feeds, deepish cuts, COOLANT, and sharp tools. Carbide is OK for roughing, but for accurate final surfaces, sharp high speed steel is required. And it produces razor wire. Copious amounts of it.
1. End result. Not perfect, but as good as I can manage. It took me 2 days to make 8 of these wheels. More work is required on the axles.
First I machined some 40mm stainless rod down to 31mm. Too late I realised that was too big.
Then I used a HSS form tool bit to cut the edge groove. But got too much chatter. So spent some time getting the coolant pump and nozzle working. Some improvement, but still some chatter. So I switched to a HSS parting tool 3mm wide, and that seemed to work well. The DRO was handy to achieve the final groove depth of 2.5mm, and 6mm wide. And then to take 0.5mm off each face to produce a boss 12.7mm wide and 0.5mm deep.
Then completed the parting off. Oh. Forgot to mention the 5mm shaft hole which was drilled.
But when I tried to install the wheels in the wheel brackets I realised that I need to remove about 0.1mm from each boss. This is the setup which I used.
2. A diamond cup wheel in the chuck, and the wheel wheel siting on parallels and held in the drill press vice. This worked pretty well, except that the quill adjustments on the drill press were a bit coarse. It would have been better in the mill with a DRO.
3. Oh. And I forgot. I used a HSS ball nose milling bit in the CNC mill, with a spray lubricant coolant, to make the face grooves. By this stage I was absolutely convinced of the need for the lubricant coolant. It made a huge difference to the surface finish. The vice did leave little dents in the surfaces of the wheels, but I had left a final machining allowance of 0.5mm to be tidied up in the lathe.
So, the first pic is the current situation, . Next steps are to make the washers for the axles, trim the axles to length, and drill/install retaining pins. These steps always seem to require at least double the predicted workshop time.
….The problem was that the 4 wheel brackets needed the wheel recess deepened by 2.5mm, and the brass shape had few clampable surfaces.
So, I tried option 1.
I machined a wooden jig to hold the bracket in the milling machine vice. The wood is Australian desert ironwood, which is unbelievably hard, but would not mark the brass. The pocket was machined to the diameter of the circular base of the bracket, and then sawn in half.
2. The bracket was clamped in the jig and squeezed tightly in the vice. Then machined with the slot cutter, the required 2.5mm deeper. The workpiece showed NO tendency to move.
1. Original brackets on the Elsternwick 80pr Armstrong RML’s. They appear to be castings.
2. Another wheel bracket style. This one on the Armstrong 80pr at Port Fairy. Cast from a different mold.
Previously I have made model wheel brackets using 2 different methods…. 1. casting 2.turning/milling
3. This bracket was cast from aluminium. It looks different from the Elsternwick example above, but is close to the original Port Fairy original.
4. This one was turned from brass, and was installed on the model copied from the Elsternwick originals. Not too dissimilar from the original, but still not quite right.
So, these are the wheel brackets which I have made for the current model Armstrong 110pr…
5. These are hot off the milling machine, and not yet finished. Those sharp edges will all be rounded and milling marks polished out.
I think that when these are finished they will look closer to the original than either of the previous examples, and they certainly look more robust and fit for purpose IMO. So, what do you think?
The above wheel brackets were milled from 38mm brass rod….
7. The slot was cut with a 5mm width slotter. 3 passes to get 11mm width. First pass shown here.
8. 75mm diameter, 5mm thick slotter. Shop made spindle fits into ER40 chuck. First ever use of this slotter which I bought years ago.
On reviewing this post I noticed that the slot for the wheel looked a bit shallow, and when I measured it I found that it is 2.5mm too shallow. A simple mistake, but must be fixed.
The problem is how to hold the workpiece while cutting the slot the extra 2.5mm deeper.
Possibilities. 1. make a circular jig to clamp the bracket in the milling vice. 2. just hold the bracket in the milling vice and hope for the best. 3.solder a 38mm cylinder to the top of the bracket, and hold the extension in the vice. 4. make new brackets.
At this moment I am thinking that I will try 1. and if unsuccessful move to 4.
The Armstrong 110pr model cannon trunnions sit in semicircular cutouts in the carriage cheeks. In the model the cutouts are 20mm diameter, and they are slightly deeper than semicircular. Making the “slightly bigger than semicircular” cutouts is complicated by the fact that the cheeks toe in towards the front, by 2.65º.
When I originally cut out the cheeks I made the cutouts 18mm diameter, allowing 2mm to be removed at the assembly time, and to then remove some extra material to cope with the toe-in angle. I did not know in advance how that would be done, but I figured that I would use a drill or reamer at the correct angle to remove the extra material.
Today was the day.
But when I was actually confronted with the task, I realised how difficult the job was actually going to be. I also realised that a drill or reamer was NOT going to do the job accurately or neatly enough.
1. These are the assembled carriages with the undersize trunnion cutouts, which do not take into account the toe-in angles. ( Since this photo was taken, the bolts have all been finished to length. See later photo.)
Then I had a brainwave. And I am really proud of this one. I made a round file, exactly 20mm diameter, and long enough do file the cut-outs together, exactly in line.
How to make a file?
And how to make the teeth small enough so they leave a smooth finish with no edge tear-outs?
2. A 20mm diameter piece of silver steel, long enough to allow filing movements plus handles. Here I am applying a fine knurl with the shop made tool which I made a decade or more ago. It is a clamp type, and can apply a lot of pressure. Run at 200rpm, well oiled.
3. I chose the finest pattern knurling wheels.
Ah! But I forgot something. When I measured the diameter of the “file” the 20mm shaft now measured 20.25mm. I had forgotten that knurling INCREASES the effective diameter. So I turned off the knurls and machined the shaft down to 19.75mm, and repeated the knurling. The diameter was now 20.05mm which I considered acceptable.
Since I was only intending to file wood, I did not bother hardening the silver steel.
4. The “file” after a few minutes enlarging the cut-outs.
5. After one minute of gently rotating the file, I could see that it was working!
6. One finished – in 3 minutes, and one to go (the top one)
7. And the trunnions fit the cut-outs perfectly!
Garrison based cannons did not use trunnion caps, unlike the naval versions, relying on the weight of the barrel to keep it in place. The centre of the trunnion is just below the top surface of the carriage cheek.
The file worked well in hardwood. I would have hardened the steel if it was to be used on brass or other metal.
The carriage cheeks for the Armstrong 110pr cannon have 10 roughly vertical bolts which attach the wooden slides, and also bolt together the thick planks which make up the cheeks.
1. Some woodworking on the vertical mill, using a very sharp and scarey shell cutter. I used to do a lot of woodworking, but these days I use the metalworking tools at their highest speeds to do accurate cuts in wooden parts. Here milling the rebates which fit the carriage into the traversing platform of the Armstrong 110pr.
The nuts for the bolts are all at the bottom end, and are buried in the slides. In previous model cannons I have milled pockets for the nuts, and tightened the nuts with a socket spanner, but I was not happy with the large diameter of the pocket which was needed to accomodate the socket spanner.
So, this time I decided to tighten the nuts using a screw driver, having cut a slot in the surface of the nuts.
2. This is an M4 nut, with a slot cut into the surface, which will be tightened with a special screwdriver. How to cut such a tiny slot? (excuse my dirty finger. This photo was taken after several hours in the workshop.)
3. The screwdriver tip which has been modified with a Dremel, to drive the slotted nuts.
4. This is the setup for cutting the slot. the nut is screwed onto some sacrificial threaded 4mm rod. The slot is cut with a thin cutting disk, 1mm thick, mounted onto a shop made mandrel which fits into an ER40 collet on the vertical mill. A bit of fiddling with the height settings, but once it was set, making the slotted nuts was very quick and easy. The slot was 2mm deep in the 4mm deep nuts. Plenty of thread remaining to tighten the nuts.
5. Slotted nuts on the right. Ordinary unslotted nuts on the left, which cannot be tightened except by making bigger holes, or slotting the nuts, which is what I did.
With the barrel almost finished (except for sights and engraving), I have returned to woodworking. The carriage was made of wood in the 1860’s.
I had previously cut out the carriage sides and the slide blocks, but now the parts need to be bolted together. Today I marked out the bolt holes, and drilled some. The holes were 4mm diameter, and up to 90mm long. Definitely “deep drilling”, despite being in wood. Due to the figuring in the wood it can sometimes be difficult to keep long series drill bits from wandering off to the sides.
1. The sides were pinned together and drilled in pairs after marking. The bolts are used to hold the slides onto the sides, and all are at different angles. Due to the tendency of the long series drill bits to wander, I started at the top where the bolts are visible, and finished at the bottom, where eventually they will not be visible.
2. The marks were lined up under a centre bit, and using a square to get the hole as true as possible.
3. 2 holes needed to have pockets cut with an end mill first. Yes, I know. Should not have used a 3 jaw drill chuck to hold the end mill, but it worked on this steeply sloped part.
4. After the drilling was finished, I could not wait to set up the barrel on the carriage to see how it would appear.
Next job is to continue the bolt holes through the slide blocks. And to make the transom. And then to enlarge the trunnion cutout to the correct size and angle.
5. The trunnion holes in the cheeks require some enlargement. The clearance of the trunnion shoulders to the carriage sides is a very neat fit. Note that handles have been made and fitted to the breech screw weights.
I am glad that I had no visitors to my workshop in the past 2 days.
The language in the workshop has been a touch foul.
Because I have been making handles for the previously made bronze breech blocks.
The handles are very small, very exacting, and difficult. In a word, I struggled.
End result photo….
1. Those little handles were used to lift out the 130lb breech block by 2 gunners. The handles swivel, and push down on the barrel, to lever the block out of the gas tight seal the block makes with the end of the bore of the barrel. As you can see from the scale of of my finger tips, they ARE very small.
I was not enthusiastic about this job. I had a feeling that it would be a bugger. And so it was.
2. First task to cut out the top of the handle bracket. Piece of cake with CNC.
3. Next, drill a hole into the bronze block and silver solder it into permanent position. Also, straightforward. The top was Loctited into position with Loctite 620, so the silver solder was not disturbed. So far so good.
4. Next job, make the actual handles. I milled a round rod with appropriately sized flats, then annealed some brass rod, and wound it around the shaped steel. Total failure. Did not take the shape accurately, and sprung outwards. So I tried it in copper. That worked better…
5. The copper wire was out of the scrap bin. 2.4mm diameter.
6. Then milled some brass rectangular section (6x4mm) and silver soldered the copper pieces to it.
7. Then cut the brass approximately to length.
8. Slit the brass to 2mm width on the mill.
9. Drilled the fastener holes and attached to the breech block with BA10 bolts and nuts.
10. And ended up with a breech block which can be levered out, and replaced into position reasonably accurately and consistently.
All straightforward.
So why all of the bad language?
Well, I needed 2 of these, so 4 handles. I made 2 spare.
I dropped one. Could not find it, despite hours of searching, including using a fibre optic 5mm diameter device to look under the milling machine and sweeping the floor. (no snakes in this cold weather. I hope). But no luck, so I made another.
Another handle jammed in the Dremel drill. I hear it hit the tin wall 7 meters away. I did look for a minute or 2, then succumbed to common sense and made another. The language really was foul.
Anyway. You have seen the final result. not too bad. Another bit of brass bling.
Yesterday I went with the children and grandchildren to the stage show musical “Cinderella”, by Rogers and Hammerstein, so I had to cut my workshop session short.
But in the few hours available I attached the weights to the weighted handle, and the lugs which contact the screw handle.
1. The weights were silver soldered to the handle, and the lugs were Loctited into position. I chose Loctite 620 rather than silver solder for the lugs, because I used different setups for the weights and lugs, and did not want to risk disrupting the silver solder from the weights joins when I attached the lugs. Some finishing required to remove the heat scale and lug protrusions. Even at model scale, the weighted handle works really well.
Oh. And by the way….Cinderella was marvellous! Enjoyed by everyone from age 6 to 72.
2. Appreciative audience after the show, exiting The Regent Theatre, Melbourne.
The billet of 1020 steel which I used to make the Armstrong 110pr breech loader cannon barrels weighed a bit over 10kg for each barrel.
1. 305mm long, 76mm diameter, 10+kg
2. 10+kg machined to 3.885kg
That leaves over 6kg of swarf for each barrel! How did I do it? I just removed all of the steel which was not cannon barrel (apologies to Michaelangelo).
The original trunnion rings of the Armstrong 110pr breech load cannons were made with a smaller internal diameter than the barrel. Then the ring was heated, installed, and it shrunk firmly into its permanent position. Heat shrinking multiple coil cylinders to build up the cannon was shown to be a very strong method, albeit expensive.
I decided to try the same method with my 1:10 model, and discussed the method at the recent GSMEE meeting. I listened carefully to the advice from members, read Machinery’s Handbook on the subject, and was ready to proceed.
The ring internal diameter was turned to 0.05-0.06 mm smaller than the diameter of the barrel where it would be positioned.
This is the pottery oven which I used to heat up the ring to 550ºc/1022ºf. All necessary tools, gloves, etc ready.
I was also told that once the ring contacts the barrel, the working time before the ring contracts is very short. So I was advised to make a jig so the ring drops exactly into the correct position. I made the jig from hardwood, and had a fire extinguisher handy.(but the extinguisher was not actually required.)CNC routing to make the jig. The trunnions fitted with 0.25mm clearance.
I let the ring soak up the heat for an hour or more.
Lifted it out with pliers, carefully lowered it down the barrel (having earlier has a couple of practice runs), and felt it slide easily into position.
Another ring followed later and it also dropped easily into position. I had to rotate it, and noted that it locked up after only 10-15 seconds, so the working time is indeed very brief!
The first ring in position. The second one was installed a few moments later, after the jig was removed. The barrel soaked up the heat, and was too hot to handle for over an hour. Note the scorch marks on the wood jig. And the line up scratches.I had mucked up the internal ring diameter of the second barrel, so used Loctite 620 after cleaning the surfaces with acetone and then the Loctite 7071 prep spray. Unexpectedly, probably because I did not use the jig with the Loctite join, I had more trouble lining up the marks with this one. I am sure that both will be strong enough for these models. After that I turned the 1º taper on the distal end of the barrels (the “chase”). The flat section is for the bracket which the breech block is placed on for loading the projectile and charge. The flat was also the reference plane for the trunnions.
I will clean up the blackened heat affected trunnion ring later. This was a very satisfying day in the workshop.
1. The centres were measured, marked and drilled. The squared end was held in a 4 jaw chuck and the end to be turned was held in the tailstock. Turned to 20mm dia with a “Diamond” tool holder and HSS 1/4″ cutter from Eccentric Engineering.
2. Then the turned end was held in an ER40 collet chuck to avoid marring the surface, and the tailstock end was turned.
3. One finished, one end to go.
4. Then I used the undersized laser cut parts to turn another “coil” (solid steel in the model, not a wound coil as in the full size cannon), also to be heat shrunk to the barrel.
Next step will be to turn the barrel diameter down to about 0.06-0.07mm bigger than the internal diameters of these parts. I will try to take some photos of the heat shrinking process for the next post.
Unfortunately the laser cut trunnion ring blanks were unusable because they were undersize. Rather than wait for another run of laser cut parts, with 3-5% increase in size to cope with the problem, I decided to mill the shapes from some old 27.5mm thick mild steel. In my last post I showed the preparation of the stock.
I made 2 of the ring blanks today. They have a 45mm hole, and to speed up the milling process I chose to use my magnet drill and a 35mm annular cutter to get the hole started…
1. It took about a minute to make a 35mm diameter hole in 27mm steel. Easy as. I had previously centre drilled the hole positions on the mill. I bought this magnet drill 18 years ago when I was building a large farm shed.
2. Before drilling the holes I had zeroed in the steel plate on the milling machine, and used the red locating device to replace the steel in the same position.
3. The left hole milled to 45mm diameter, 4mm depth per cut with a newish 8mm carbide bit. Just starting the second one. Much easier enlarging an existing hole than milling a deep slot.
4. Milling the outline, ramping down…..2500rpm, 150mm/min
5. …and I quickly added a spray-mister to provide lubrication, cooling and chip clearing from the deepening slot.
6. I did run into a problem with the tabs. I made them 1mm thick, but forgot that Vectric calculates the tab thickness from the bottom of the cut, not the bottom of the material. And the tabs broke before the milling had finished. Fortunately the workpieces survived.
7. The parts had 5mm taken off the wings which will later become the trunnions, then used a rounding over milling cutter as a form tool in the lathe to make a rounded fillet.
8. 2 of these made today. Tomorrow I will turn the trunnions from the squarish ends.
As explained in the previous post, it was crucial that the breech screw was tightened securely.
Watch the following YouTube video of a demonstration firing of a 110pr at Fort Nelson, video’d by Nick Cafferata, and used here with his permission. Note how the weighted handle was swung by 2 gunners and repeatedly knocked to ensure secure closure. Also note the volume of smoke from the firing, and this was a charge of only 2lb, compared with the 10-11 lb used in 1861.
2. The laser cut parts for the screw handle (left) were excellent. Unfortunately the blank for the trunnion ring was slightly too small so I will use another method to cut another using my CNC mill.
3. Milling the screw octagon on the breech screw. CNC rotary table. Beautifully accurate.
4. Octagonal piece heat shrunk to breech screw. I probably could have cold pressed it on, but I wanted to try heat shrinking because that method will be required later when fitting the trunnion ring. It is strongly held together, not budging when I turned the rear surface to 4mm thickness.
5. 1.6mm drill for the pins. This worked well after I loctited the handle to the screw before drilling. 25mm depth of drilling definitely qualifies as deep drilling. Then I heated the assembly to break the Loctite bond. Then turned a 1.6mm wide, 0.8mm deep groove in the shaft using the drilling marks as a positioning guide.
6. Facing the handle and screw. This was also completed before breaking the Loctite bond. Not a precision task, so quite happy to use the 3 jaw chuck, which is actually surprisingly accurate.
The central 18mm diameter shaft was also heated to break its Loctite bond and the shaft came free.
Next job is to make and attach the blocks to the handle which knock the octagon/breech screw, and the heavy weights to the ends of the handle which enhance the momentum of the action.
7. I had this piece of mild steel 28mmx168mmx600mm left over from a farm machinery job years ago (a deep ripper for a bull dozer, for preparing the ground prior to planting olive trees.)
8. It was rusted from sitting in a pile of steel for 10-15 years, so I took off 0.5mm from each face to flatten it and clean it up.
Watch this space to see it being CNC’d into a trunnion ring…….
If the screw which held the breech block in place was not tightened, when the gun was fired, explosive corrosive gases would escape backwards rather than propelling the projectile. An inefficient and destructive result.
If the screw was not not tightened at all, the breech block, which weighed 130lb, could be ejected with great force, and devastating, potentially fatal results to the gun crew.
So it was important that a gas tight seal was achieved when the block was inserted and tightened. That required a seat like a valve seat in an internal combustion engine, and a corresponding 45º angle on the breech block.
First I made the breech block. The plug was turned from LG2 bronze. This will seat against the steel barrel bore. In the original the block was made of steel or iron, and it seated against a copper insert seat. I decided that it would be too fiddly and difficult to reproduce the original steel/copper system, so I substituted the bronze block which fitted against the steel end of bore in a 45º seat.
2. cnc turning the bronze breech plug. The cylindrical section fits into the 18mm bore. A similar cylindrical section on the other end fits into the breech screw. The 45º section is seen.
3. A further final contour, then parting the plug from the bronze bar. I finished the parting by using a hacksaw.
4. The plug is 31mm diameter, 16mm thick.
I used 2 tools to make the seat. A commercial carbide seat cutter, and a shaped stone to finish.
5. The brass shaft and pilot were each 18mm diameter, and fitted neatly in the bore and breech screw.
6. The stone was given a 45º bevel using a diamond. The ways were covered and thoroughly cleaned afterwards.
The seat was cut with the carbide cutter, by hand and using cutting fluid. When it was 1-2mm wide, some chatter marks were just visible, so they were polished out using the stone, also by hand.
7. The chatter is visible, along with the chips which were produced by the carbide cutter. I don’t have a good photo of the end result, but it looked much better than this.
8. The hole underneath was to drain water after swabbing/post firing. The breech block is just visible.
And today I picked up some laser cut parts from the cutter. (JR Laser, Geelong)
9. Minimal cleanup was required on the 6 and 8mm thick parts. Some extra machining is required. But the 25mm thick part has some problems. It is a little undersize. Apparently caused by heat expansion of the steel during cutting. I have not yet decided what to do about this problem. I might have to get it re-made 2-3% bigger. Or I might remake it myself on the CNC mill.
So, the model engineering of the Armstrong 110pr breech loading cannon continues….
Still a fair bit of machining to finish the Armstrong 110pr breech loader.
And I was wondering whether I should spend my time fixing a very run down house rather than making model machines.
I know what I would prefer to spend my time on. And I do NOT like climbing up ladders any more. Age 72!
But SWMBO is not well. 25% of the way through chemotherapy. She is coping well. I am OK. Just.
And, I had decided that the Armstrong 110pr would be my last model build (well, not counting plastic models which I can assemble in front of the TV.)
….But, when I saw these drawings of an 1899 steam driven wharf crane, drawn into plans by Julius deWaal, I am sorely tempted.
A 1:12.7 model would be about a meter high. Contains a boiler (which would require certification), a twin cylinder double acting steam engine, THOUSANDS of rivets, many gears including bevel gears.
But, is it not beautiful, magnificent. And there are excellent plans (thanks again Julius deWaal!), and best of all, the original is less than an hour away from me by air, in Hobart Tasmania!
While I am waiting for some laser cut parts for the cannon, and tools from India, I MIGHT just start accumulating materials for this one.
The exterior shape of the barrel is one of the final steps. The basic cylindrical shape is retained as long as possible to facilitate work holding in the milling vice. Here the axes are marked. The rifling can be seen. The exterior final shape of the breech has been finish turned prior to milling the breech block cavity.The rectangular cavity is up to 20mm deep. 24mm x 16mm. I started by drilling corner holes, then used a new 8mm end mill taking 4mm deep cuts.After the 8mm endmill, the walls were tidied with a 6mm endmill. Have I mentioned before that I love CNC.This is the first time that I have tilted the milling head. It was easy, and quite predictable and steady. 20º.Not a perfect finish, but it will do. Maybe a bit more filing. The breech piece fits down there, and the breech screw locks the breech piece against the end of the bore.
A few photos of painting the model Yamato. I used Tamiya paints. Spray cans for the large areas- and hand brushes for the small ones.
1. The entire hull was primed, then the water line masked.
2. Masking tape to define the waterline, then a quick, careful spray with dull red. Lovely colour. Not dull at all.
Then removed the masking tape and applied some more tape over the red. Painted the top half of the hull, and the other modules, “battleship grey”. Then glued the modules together.
3. The wooden decking is laser cut and the individual planks are laser marked. Incredibly thin… not measured but maybe 0.25mm. And have a paper backing which when removed exposes the adhesive. The pieces are extremely accurate for the model, fitting into their spaces and around winches, guns etc. NO trimming was required. My only issue was that some areas required extra adhesive. I used Tamiya Ultra Thin Glue, and it worked well. Great care was required in positioning the sheets.
4. And some hand painting of small details. The superstructure tower, funnel, 5″ guns, anti-aircraft cannons, and main aerial. The wooden decking was then applied. See how accurately it fitted around all of the deck machinery and guns…
5. A close up of the wooden decking detail. Very impressive! And not expensive. Cost about $AUD20 including postage.
6. The fore and aft flag posts are very fine, and inclined to catch in clothing and break. After repairing them at least 10 times, I reinforced them. Can you see the dressmaking pin? The cavity to the left of my finger is the lifting well for the aircraft, leading to the hangar.
The end result….
7. Superb shape! And this photo reveals that at least 95% of the ship volume is within the hull.
8. 9 18″ guns in 3 barbettes. The wings on the barbettes are range finders. The decks around the guns were kept as clear as possible because the blast from the 18″ guns was huge. 20kg/cm^2
9. Yamato could carry up to 8 spotter planes. Launched by catapult, and picked up by the crane at the stern.
The model is complete, except for the flags and aerial cables. Took me a week to make and paint. I really enjoyed the build. And I really like the model. It was not an easy build, but the real credit goes to the people who designed and made the kit. It is truly impressive how well everything fitted together.
Now. Where to put it? And how to keep it dust free?
The 1:350 Yamato model is made of plastic. Mostly Polystyrene, but also a small amount of ABS. Different glues required for each type of plastic. Both types will hold the parts in a minute or so, but several hours are required for rigid holding.
There are 17 different colours specified, which explains why the paints were so (unexpectedly) costly. Mostly IJN grey, and dull red, for the hull exterior, and wooden deck tan. I bought Tamiya spray cans for the dull red, IJN grey, and primer. The wooden deck tan was unavailable, so I bought some laser cut sheets of impossibly thin wood, already in the correct colour, and made for this particular model. Pictures later.
So I sprayed the primer coat.
The question was whether to make the entire model, then paint; or paint the individual parts on the sprue frames before assembly ; or something in between.
I thought that painting the entire model would be simplest, but some small parts and areas would be inaccessible, and the result would be messy.
Painting every component on the sprues would leave a bare cut area on every part which would need to be touched up later, so that did not appeal. Plus it would be very time consuming.
So I decided to make the ship in modules, and paint each module separately.
1. The painting modules….. the hull is just 2 colours, IJN grey, and dull red below the water line. Some masking will be required. The other modules will be painted individually. As seen, 99% of the gluing has been finished.
2. So today I applied the primer coat. The paint is touch dry in about 10-15″. I started with the underside of the hull, then turned it over, on the box as support, and painted the decks. The box was exactly the correct size to support the deck without damaging the tiny attachments.
3. Then the smaller modules. The alligator clip attached to a chopstick was a handy way of rotating the workpieces, and minimising painting my hand.
4. Still some small parts to be attached, but they will be different colours which is my reason for not attaching them before this. This is one of the 18″ gun barbettes.
Tomorrow I hope to start applying the final colours.
Painting is really NOT my thing. So to finish the day I spent some time restoring an old small Westcott adjusting wrench which had been given to me by a friend.
4. Still some small parts to be attached, but they will be different colours which is my reason for not attaching them before this. This is one of the 18″ gun barbettes.
5. I tried to cold bend the fixed jaw but it would not move. So I used a hand hack saw to open up the crack, then bent the jaw back towards a right angle. 3 successive cuts and bends were required to get it back to 90º.
6.Then V’d the cut, almost to the box inner section. Then arc weld filled the V. It wont be as strong as the original, but will be OK for light applications.
7. Finally some time was spent grinding and sanding the weld flat, and filing the parts make them slide easily. It was still a bit sticky, so some “Gumption” was used to smooth the action. The handle was cold bent back into a nicely curved shape. I might get around to blackening the wrench by heating it and quenching in dirty sump oil.
So far, glueing up the model has been interesting and a lot of fun. Look at the progress after 2 days….
The guns and superstructure are just sitting there. The components will be separated for painting.
The tools which I have found useful are lined up.
Alligator clip on a chop stick, rubber bands, Extra Thin Tamiya Glue for polystyrene plastic, flat non serrated small pliers, needle nose small pliers, safety razor blade, sharp side cutters which I have modified so the cutters are thin and very pointy, steel ruler used as a scraper, small fine file, fine sand paper, fine tweezers (actually from my microsurgery kit of 30-40 years ago), coarse strong tweezers, and utility knife. And of course an A2 cutting board, and Tamiya Instruction book which I have found to be accurate and very helpful.
The Extra Thin Tamiya Glue is very good. It sets in a couple of minutes so parts can be finger held in position. It is so thin that it tracks into small cracks by capillary action. And it is transparent. Time will tell how paint adheres to the glue.
The Tamiya parts are also very impressive. Beautiful smooth finish, minimal flashing which can be scraped off with a finger nail. And the parts fit together very accurately, for the most part. Rarely I had to use the razor blade to make parts fit together, and that was usually because I had missed a bit of the sprue when separating the parts from the sprue.
This was one of the first areas to be glued.Large joins, like this foredeck to hull, were glued progressively, holding each bit with a rubber band. The deck has a bend, and I could not hold it in place with only my hands, but the rubber bands worked pretty well.
It was quite exciting to see the hull coming together.
Many of the parts are extremely small, and too light to feel. The fine tweezers are very handy for these. So far I have lost only one part after dropping it.
I am close to painting the components. I will use Tamiya spray cans, brush applied paints for tiny parts and fine lines, and possibly an air brush. I have been watching YouTube videos to pick up hints on the painting process. It was surprising to me just how many YT videos exist on the subject of painting model Yamatos.
Then the major components are glued together.
Then the smaller guns and other surface equipment will be glued on to the painted surfaces.
P.S. Another 1/2 day gluing up these tiny planes. One more to go.
These really tested my eyes and hand control. Cotton bud for scale.This cheap Banggood LCD microscope was very useful. Only trouble was that it magnifies my shakes. (Mustool G1200)odel
In common with many other males, (whoops. Possibly females as well, although I know of none.), I have long had a fascination with battleships. Of all eras from the ancient Greeks and Romans, Nelson’s, dreadnoughts, WW1 and WW2. Read the novels, made models from kits and from scratch. I have quite a library of books.
Recently, I purchased this book…
It was not cheap. But absolutely worth every cent. Available from various vendors. I got mine from Amazon.
336 pages. 350 colour views, including some original photographs, and lots of details. 1020 scale drawings of excellent quality. 43 pages of history and specifications. The bulk of the book is superb quality pictures and drawings.
These battleships, at 72,000 tons, were the largest ever constructed. And they mounted the biggest guns ever used on a battleship at 18.1″. Each of the 3 gun turrets weighed as much as a heavy destroyer, 2500 tons. They were 250 meters long, and 50 meters from keel to the top of the superstructure. Their 4 turbine engines drove the ships at 30knots/50kph. Each ship had 25,000 tons of armour, up to 560mm thick!!
“Awesome”, seems insufficient.
The Imperial Japanese Navy had them built to outgun the most powerful battleships of the US Navy and western powers. However they were dinosaurs, and both were sunk by aircraft. Neither fulfilled their intended role of fighting other battleships.
The book is divided into 4 sections….
Section 1: Introduction, Superbattleships and Summary of Service. 43pp.
Section 2: Primary Views. 25pp.
I cannot overstate the quality of the drawings. Just magnificent.
Section 3: The Drawings. Subdivded into general arrangements, Hull structure, Superstructure, Rig, Armaments, Fire Control, Fittings, Aircraft, Boats, Author’s Model. 252pp
18 pages are devoted to the 18.1″ guns.
Section 4: Yamato and Musashi at sea, Remains of Yamato and Musashi 12pp. The pictures “at sea” are computer constructions, using the author’s model, and incredibly convincing. Initially I took the pictures to be of the originals.
Both ships were sunk by massive US air power, with the loss in Yamato’s case of 90% of its crew of 3,300 sailors. Almost as sad, almost all of the original construction plans and details were destroyed by the IJN after the Japanese surrender.
So, if you have any interest in battleships, massive marine engineering, WW2 naval history, or ship modelling, this book is an absolute must.
Consequences??
After reading the text, and going through the pictures multiple times, and being captivated by the wonderful lines of the ships, I decided to make a model of Yamato. Kits vary from 1:1000, to 1:100, with the larger scales being in the thousands of dollars.
I made plastic assembly models when I was a kid, and once as an adult when I was laid up for 6 weeks after an injury (see later photo). In this case I settled on this kit. Tamiya is a well respected brand. The kit is 1:350 scale. Cost about $AUD150. I hope to interest a grandson to get involved.The paints required cost almost as much as the Tamiya kit!The ABS plastic components look excellent, with hardly any flashing, detailed instruction booklet. There is provision for batteries and remote controls, but I doubt that I will go that far. The hull is big! 751.5mm long.
The following is the only surviving plastic model of mine. Another ship with wonderful lines.
Cutty Sark. Even after blowing off most of the dust, it looks more like Shackleton’s “Endurance”. And needs some TLC.
A question to my readers….. would the progress of making the model Yamato be of any interest?
For reasons which I will not detail here, I am spending more time at home, and much less in my workshop. Work on the Armstrong 110 pr breech loader is progressing, slowly. However, the rifling is complete.
I detailed the rifling setup in a previous model build, but in case you missed it……
The barrel is held in a jig which is clamped to the CNC mill quill. The mill spindle is turned off, for obvious reasons. The cutter protrudes from a 16mm shaft. The brass bush increases the diameter to 18mm to fit neatly into the bore. I should have remade the entire shaft with 18mm bright steel, but I thought that this modification would work with a lot less trouble. It did. Sort of. The cutter was 3mm wide, and I ground the actual tip to 0.9mm width.The cutter is mounted to the CNC rotary table with an ER40 collet. The depth of cut is determined by the screw at right, and the maximum depth of cut set with the 2 locked nuts. The mirror is for inspecting the cuts which finished underneath and at rear.
The setup took several sessions to complete. I had previously drilled and D bit finished the bore, and drilled and cut a large thread to accept the breech screw. Then I turned the exterior of the barrel so it would fit the jig. It will be turned to its final shape in a future session.
I could not find actual specs for the twist, so I randomly decided on 90º. The cut started in the powder chamber and finished just beyond the muzzle. The rifling in the original started distal to the projectile chamber, but I had to ignore that due to limitations of my setup in accessing the adjusting screw. The powder chamber and projectile chamber were slightly bigger than the bore in the original, so I might be able to machine away the unwanted rifling in those areas in my model.
30 rifling grooves in the model. The original had 76. But in an 18mm bore the 30 cuts are only 0.9mm wide, and that was as fine as I was prepared to grind the cutter. The cuts are about 0.25mm deep, which is to scale. I will polish the bore later.
This is the breech piece. From a 1.25″ high tensile bolt, with an 18mm hole drilled and reamed. The thread is 8tpi. An unusual pitch for the size. 60º form. Further shaping of the ends to come, but I decided to make the female thread in the breech first.I cut the thread on the lathe manually, but the HSS cutter tip broke and I had to regrind it after the thread had already started to form. As you can see, the reset cutter position was a bit out. But I corrected the position and pressed on. How do the experts reposition a threading cutter? As per the original threads, I left flats in the female floors, and ground off the peaks of the male thread. (someone can correct my terminology here…)Anyway, the breech piece threads in snugly and nicely. Quite tight but screws in by hand.…and an 18mm silver steel rod fits well into the breech piece and into the bore of the barrel, so the threads are well aligned.
Despite the errors, this thread has worked out pretty well. I have learned a lot, and I reckon that the next one will be better.
The breech piece will next act as a tailstock centre for turning the exterior of the barrel between centres, after removal of the fixed steady.
This project is progressing slowly. Other issues are taking time at present.
There are 3 major components on these cannons…. the traversing platform, the wooden carriage, and the iron barrel. And a number of smaller components… the compressor (the recoil suppressor), the elevating mechanism (Smith’s screw), the sights, and various rope eyes.
I usually have something in mind to work on when I enter my workshop, but sometimes I just proceed where the mood steers me. I have actually been working on all 3 of the major components, with most progress on the traversing platform, which explains why the posts have been rather fragmented. Most of the work so far has been woodworking, but recently I had an urge to do some metalworking. So I made a start on the barrel.
The first step was to buy and cut to length the 1020 steel shaft. Then the piece was mounted in the 4 jaw chuck, and dialled within 0.05mm at the chuck. The tailstock end was supported in the fixed steady, and also dialled in. I was not trying for perfection because it is a case of time and diminishing returns, and straightness of the bore and concentricity between the bore and the exterior of the barrel are the main concerns.
So, the next step was to drill the bore to 16mm, using the extended drill bit which I had fabricated for the previous cannon, after centre drilling. The resulting hole was 305mm long, appeared to be straight, and just a bit rough.
Drilling the 16 x 305mm hole took 15″. I touched up the drill bit cutting edges with a diamond lap, and cleared the swarf every 10mm or so. Plenty of cutting fluid used.
I wanted a final bore of 18mm diameter. I have an 18mm reamer, but only 120 mm long, so I made an extension rod to fit the Morse 3 driving tab. But first I had to drill the bore closer to 18mm. So I made a D bit from undersize 18mm drill rod.
The silver steel / drill rod is 17.94mm diameter. The flat is milled, removing 8.94mm and leaving ~9.0mm. The cutting end was hardened by heating to cherry red , then quenching in oil. It was still able to be filed, so not hard enough, so I repeated the heat-quench cycle, using a water quench, and that worked well.Using the belt sander to give some side and rear relief. Later I added a chamfer to the cutting corner (see next photo).Cutting corner on the left.The “business end” as requested by John Marshall. This is after cutting through 305mm of 1020 steel, and it needs another touch up with the diamond lap. initially I used the D bit as shown on the belt sander above, but the cut improved after the bevel was added with relief to the cutting corner. The only purpose for the recess is to accumulate swarf during the cutting process. But the recess fills quickly and it needed cleaning out every 5-10mm of drilling depth. The D bit was held in a 40ER collet in the tailstock. Plenty of cutting fluid was used. The chips were cleared every 5mm of cut. The D bit was sharpened 3-4 times during the process using a diamond lap. Enlarging the bore to 17.95mm with the D bit took 15min.This was taken after using the D bit. The surface finish was improved further after passing the reamer. I am not concerned by the rough appearance at this end because it will be machined out to 28mm for a depth of 50mm to accomodate the breech screw and breech plug.The breech screw is shown in drawings of the era as a buttress thread, with a pitch of approximately 1.25″. I have some 1.25″ diameter threaded rod, category H2, with a pitch of 1/8″ which at scale 1:10, is very close to the original, although not buttress profile. The drawing is very close to full size for the model. I drilled, D drilled and reamed the through hole, and am considering how I will cut the thread into the breech of the barrel. Still pondering whether to try to cut a buttress thread…
And the traversing platform now has the metal surface strips screwed into position..
The 1mm thick stainless steel strips had been laser cut and 2mm holes laser drilled. I had to countersink the holes so the screw heads were at or below the surface, so provide a smooth surface for the carriage slides and trucks (wheels). The countersink tool is carbide. I wanted a smooth flat surface to work on, so used a fly cutter on the wood to produce such. The counter sink bit self centres well.The screws are 1.6mm diameter. In that size I had to settle for Phillips heads rather than simple slotted. The larger circular cutouts are for the wheel posts, yet to be made.
Having commenced building a 1:10 scale model of this gun on a wooden carriage and traversing platform, I am also finding information about its history. First the build progress….
Glueing the traversing platform pieces. And a 4mm long series drill bit.
Gluing required some planning. The brass stops rebates were tricky to make last time because the platform was already fully assembled. So this time I made the rebates and installed the stops prior to gluing up.
Then there is the matter of the long, 4mm, holes across the multiple pieces of the platform, which is up to 152mm wide. Wood is not uniform like steel or aluminium, and deep drilling wood with small diameter drill bits usually leads to wandering crooked holes. So I measured and drilled each piece separately, prior to assembly. A tricky and exacting process. All except for the outside pieces shown being clamped above. They were drilled, one side at a time, after that side was glued, using the existing holes as a drill guide. I was happy with the results of the drilling and gluing.
Cutting out the carriage cheeks with a 6mm endmill. The workpiece is screwed to the sacrificial base piece with large woodscrews (not visible), then the required holes for the model are drilled through workpiece and sacrificial base and bolts are inserted. These bolts stop the workpiece from moving in the final stages of cutting the part free. The carriage cheeks will not be parallel in the final assembly, being narrower at the rear than the front, and the holes will need to be modified at that stage, so I have drilled them undersize at this time. Same goes for the trunnion cut outs.Glued and drilled traversing platform (one of 2); laser cut 1mm stainless steel strips ready for attachment (AUD$55 including material. Probably saved me a day and more accurate than I would have managed), and CNC cut carriage cheeks, straight off the mill. Recycled Victorian Mountain Ash floor boards).
Not so much workshop time lately due to family factors, so I have been reading and searching references. And thinking about how to machine the barrel. Important to get the sequences right. And to have available the correct tools.
A is the screw which compresses the breech block E into the copper seals F and H, after the projectile and charge have been loaded through the breech. B is the weighted handle which operates the screw. C is the breech coil. D and J are further coils. K is the trunnion piece which was forged including the trunnions.
The originals were made using the Woolwich “coil” system, in which components of the barrel were made into various sized and shaped cylinders by winding white hot strips of iron or steel around a mandrel, then hammer welded into a single fused mass. The various cylinders were then accurately turned on large lathes into the final pieces which were heat shrunk together, and finally furnace welded. The Armstrong 110pr had 7 such major pieces. Only the innermost barrel cylinder was steel.
There were 2 barrel designs of the 110pr guns. The above diagram is the 72cwt version, which was 2″ shorter than the 82cwt version. The latter has more taper to the chase of the barrel, and will probably be the one which I model.
The 2 types of 110pr barrels. You can see my metric conversions of the dimensions. And a few dimensions scaled off the drawing. I think that I will make the 82cwt version.
I will not be making my model using the coil method, but I am probably going to make the trunnion ring with trunnions as a separate item, and shrink it onto the barrel, along the lines as described by jefenry.com. Still thinking about those big asymmetric double start threads on the breech screw. I have a high tensile 32mm bolt and nut which I am considering using.
The scaled bore should be 17.78mm. I will approximate that to 18mm. Will need to extend a 17.7mm drill bit, and to make an 18mm D bit from silver steel. Jefenry welded an extension to an adjustable reamer to finish his bore. I will possibly use that technique also.
So. Having made the decision to make a model rifled breech loader, Armstrong gun, on a wooden sliding carriage and wooden traversing platform, I gathered my references. A lot of these guns were made, 959 in use in 1878. Many on wooden carriages, some on iron carriages. They were used in several wars, and I will be delving into the history. Examples of the guns exist in quite a few countries including UK, USA, Canada, and Australia. There are references in Wikipedia, and several artillery books of the era (1860-1890). Various models have been made and documented, including good descriptions, particularly by jefenry.com.
I have several reasonable scale drawings, including some kindly sent by jefenry. (Thanks again Jeff!)
This is the 110pr breech loader on a sliding carriage, and standard traversing platform.
In the drawing above, the traversing platform is identical to the ones under the 80pr Armstrong RML’s which I recently modelled, so my previous experience will be useful for the current build. The carriage for the 110pr RBL is similar, but not identical. The barrel itself will be quite different, and will be the main challenge in the current build. Apart from the breech block, and breech seal, there are 76 (!) rifling grooves, compared to 3 rifling grooves in the RML. I am already thinking that I will be reducing the number of grooves, to maybe 28.
Another handy resource which I found during my Internet searches of Armstrong 110pr’s, is ETSY.com, a Canadian site, where the Armstrong 110pr has been CAD drawn in very fine detail, and available for $AUD34. The drawings are not perfect in every detail, but even so I rate them as very good. Only available as Fusion 360 files, but Fusion 360 is available free of charge for hobbyists, with some restrictions relating to file numbers and some features.
Yesterday I purchased a lump of 1020 shaft, 1270mm long. I only required 305mm, but the supplier was unable to cut it for 3 days, so I took the whole piece. A burly worker picked it up as if it was made of balsa wood, and put it in my car. I struggled to unload it at the other end. 40+kg/ 90lb.
Wanting to get started, I cut off two 306mm billets.
…and weighed the 306mm piece…
10+kg
The next step for the barrel is to rough drill the bore. I have an extended 16mm drill bit from the previous model, but will have to modify a 17.75mm bit and extend an 18mm reamer or make a long 18mm D bit, before I can proceed. So instead, today, I made a start on the traversing platform.
Actually, I have decided to make one for myself, as well as the intended gift.
Having made a few errors in the machining sequences last time, hopefully I can avoid the mistakes this time. Also, with multiples of some components, such as wheel brackets, and rope rings, I will be casting some of these in bronze, and getting laser cut parts for others such as the metal slides.
The original Armstrong barrels were constructed in multiple pieces which were shrunk together, using the “coil” method to construct the pieces. The trunnions were on a separate ring which was forged, then machined to final shape, then shrunk into position. I am considering machining the model trunnion ring separately, and shrinking it into position, but the rest of the model barrel will be turned from a solid piece of 1020 steel.
I had thought that the 1:10 scale model Armstrong 80pr rifled muzzle loader would be the last cannon which I would make. It is currently being given finishing coatings to the woodwork. Later this year it will be given as a gift to a family member.
To be honest, having made five 1:10 scale model blackpowder cannons, I am ready to move back to my first modelling passion, which is steam engines. I had no real interest in weapons or guns or artillery, except as a means of increasing my understanding of history, specifically military history. I have no interest in firing guns, although I must admit to an illicit satisfaction in watching You Tube videos from USA of cannon modellers who can actually fire their creations.
My interest in cannons started when, as a newbie in CNC machining, and looking around for a project to use my newly acquired CNC lathe in 2015, I made a model long gun.
1:10 scale models of a 1779 24 pounder long gun, and 1804 carronade of the same bore. Making them was interesting, and the associated history was totally engrossing.Then the Ottoman cannon of 1465, again 1:10 scale, over 500mm long.
The Armstrong 80pr muzzle loader, scaled from the originals at Port Fairy and Warrnambool.Another Armstrong RML 80pr. I kept this one.
And the most recent Rifled Muzzle loader, the same 80pr Armstrong Barrel, on a Dwarf carriage, and wooden traversing platform.
Almost but not quite completely finished in this photo. Since then it has been cleaned, stained, and lacquered.
I truly thought that this would be the final cannon which I would model. So I could get back to my model steam engines.
Like this one from 2-3 years ago, now gracing our kitchen, with decorations by SWMBO.
Trevithick dredger engine and boiler, of about 1805. 1:8 scale. The possum and the budgerigar are not real. Neither are the two T. Rex’s fighting on the boiler.
BUT….then my eldest daughter, who has absolutely NO interest in cannons, asked ” are you going to make a cannon for me?” I must point out that this daughter rescues injured animals and takes them to her vet, is vegan, the most pacifistic and socially conscious person that I know. I questioned why she would want a model cannon. “I just do” she replied.
Oh well. I guess that I will be making one final model cannon.
I spent a day searching my books, Google Images, Wikipedia for a cannon which would look interesting as a model, be interesting for me to make, and for which some plans or drawings are available. I offered my daughter the choice of my existing models, but no, she wanted one built just for her.
Then I thought of jefenry, my reader from the USA, who has made several model cannons, including one which intrigued me when I first saw his pictures and videos several years ago. It is a 1:9 scale Armstrong rifled breech loader, 110pr, of 1861. One of the first breech loaders of relatively modern times. (Breech loading cannons have been around since medieval times, but they were less reliable than muzzle loaders, more inclined to explode and kill their own gunners.). The Armstrong 110 pr RBL saw action in several wars, including against Japan, the NZ Maoris. It was the largest cannon on HMS Warrior, but was replaced by the more reliable muzzle loaders.
So that is what I will model for my daughter. An Armstrong 110pr, rifled breech loader, on a dwarf carriage and wooden traversing carriage. Here are some pictures.
110pr Armstrong at Fort Henry, Canada. I presume that the traversing carriage is a reconstruction.And the 1:9 model of a naval version of the gun, which was made by jefenry. Check out the making of the cannon, including rifling, at jefenry.com and watch his video of firing the cannon at https://youtu.be/m3pC0eDvs90
So, my plan is to make a 1:10 model of the barrel, on a carriage and traversing platform like the Fort Henry example above. Not sure how much of the build will be featured on this blog. I am again very close to my WordPress.com memory limit.
These daily posts might be becoming a bit tedious but you need to realise that I write them for my own diarising purposes as well as entertaining yous.
First today, I deepened the countersinks on the carriage stops which I had installed yesterday, and filed the bracket surfaces until the carriage showed no signs of catching on high spots. Then reassembled all of the bits in the vicinity.
I had machined some hardwood (Australian Mountain Ash, a close grained, hard, stable, pale hardwood) for the side steps, and today I made the brackets to support the side steps.
There are side steps on both sides. The one not visible is smaller. R1 R2 and R3 are the steel supports.
But, when I examined the steps today, I decided to remake the side steps, using the dark red hardwood Jarrah, the same as the rear platform.
The Jarrah side steps. They will age to a dark red colour, like the rear platform. The grey desk mat is A2, to give you an idea of the scale.
The steel brackets were cut from 50mmx25mmx1.5mm rectangular section tube.
Cutting the RSS.Bolted to the side steps. They look a bit rough at this magnification. The lip at the top is cold bent.The U bolts are bent brass rod. I intended to Loctite them into the drilled holes, but they needed to be hammered home, so I think that glue will be unnecessary. (I made 2 extra)
So, I think that those are the final parts to be made for this model. Now I need to decide about finishing the wooden surfaces. At this stage I am thinking of a dark wood stain, then a satin finish with a wood oil.
Firstly some woodworking to make the platform floor. Basic machining, drilling and screwing.
Quite pleasant to do some basic cutting on the bandsaw and thicknessing on the mill. HSS metal mills give a good finish on hardwood. It was finished quickly, and went so well that I proceeded to a task which I had been putting off, because I knew that it would be very difficult.
I made the carriage recoil stops, and installed them.
The problem was that the platform had been previously assembled, including gluing of the joints. And I was not going to break those joints for anything.
The recoilatop is on the inside of the platform slides, at the rear. Shown here above the bollard. It is recessed into the slide so only the actual iron stop is above the surface. Also, it is underneath the bracket which supports the gunner’s rear platform.
The stop bracket is about 30mm x 6mm x 2mm, and the stop protrudes about 5mm further. So the first question was how to make the rebate. The distance between the slides is only 53mm. Not much space to use chisels. And end mills could not be used. The metal surface of the slides is glued and screwed to the slides, so removing those was not an option either. I should have made the rebates BEFORE I glued up the platform. Oh well….
This is the setup which I used….
I bought some Woodruff cutters and T slot cutters at a sale some years ago. So I cut the slots with one of those. The cutter worked well, but it left sloping ends. One of the ends is hidden behind a bracket, but the other one is visible. Used the inspection mirror to watch the milling on the near slide.
So how to square up those ends. Not enough room to get a chisel into that space. Still wondering, I made the actual stops.Making the stops involved some basic milling and silver soldering. The steel nut got a bit chewed up during the slotting. It will not be visible in the final assembly.
Then, rather than squaring up the recess, I rounded the hidden corner of the stop bracket. Easy!
Drilled the holes in the stop brackets for the screws, fitted the stops into position. Now, how to drill the holes in the wooden slides for the screws? The holes in the wood were only 1.4mm diameter. And a 1.4mm drill bit is not long enough for the drill chuck to miss the other slide. To avoid the other slide the hole would be excessively angled.
So I used another trick which I have used previously. I silver soldered the drill bit into some fine (2mm OD) copper pipe….
1.4mm, 1.6mm, and 2mm drill bits given substantial extensions. I used copper for the small sizes because I had some suitably sized pipe. I had drilled the hole in the brass rod for the 2mm extension for another model.The extension meant that there was only slight angulation of the hole when drilled with a battery drill.
I will enlarge the countersink on the stops to bury the screws deeper, then file the screws flush with the stop surface. I doubt that the bit of angulation will ever be noticed. I used steel screws, because a brass one snapped off and I had to drill through the remnants. The steel screws are slightly bigger than intended, but not excessively. I had removed the gunners platform to improve the access. The area will look tidier when fully reassembled.
I am very glad that particular task is all but finished!!
ps. I have called them “stops” but that is probably not the correct term. The recoil of the carriage is reduced by the 5º slope of the slides and the braking from the compressor. The “stops” (or whatever they are called) are the final impediment in limiting the recoil of the carriage and its barrel.
Today I milled the rebates which the wheel brackets fit into. Only 1mm deep and at an angle of 15º to the base line. It went fairly well, but when I reversed the milling pattern for the reverse sides, It went a bit askew by about 0.5mm. Not much, but enough to be noticeable, so I filled the defect with wood putty.
Then I milled the 3º chamfer in the wheel brackets. Straight forward process.
Finally, with the brackets sitting correctly in their rebates I wondered how to make the bracket retaining bolts, and the wheel axle shaft.
The bolts have dome heads.
I prefer to use stainless or brass bolts, but none come with dome heads, so I considered various options. I chose to use a method which I have used previously.
I selected some 3mm stainless cap screws, and filled the head with 50% silver solder.
I needed 4 dome head bolts for the brackets, so made 6, just in case.at top is the lathe ER40 collet, which is holding a smaller ER16 check and collet, then a 5mm screw for form turning with the milling rounding over bit. It all worked well, with only 2 failures. In the above photo the turning has not quite fully formed the hemispherical head.
…And used a rounding over milling bit, held in the toolpost, to round over the capscrew head and its silver solder filling. The first screw bent during the form turning, so I placed them deeper in the ER collet chuck. A later one broke, so I slowed my feed rate. I ended up with 4 bolts.
I did the same with some bolts for the axles, but they are fully threaded, so this will be a temporary solution until I can make more suitable axles.
But you can see how the brackets, wheels, bolts and nuts will appear.
You will notice the filled hole in the carriage cheek. That was a mistake, but rather than start the cheeks from scratch again, I chose to fill the holes. They will be almost invisible when the cheeks are finished, I hope.
The axles are temporary. I am happy with the brackets.I am showing the best side here. Looks OK?
The Armstrong 80pr rifled muzzle loader at Hopetoun Gardens, Elsternwick, Victoria. One of two. On the Elsternwick guns the slides have been covered with sheet metal covers to protect them.
The carriage wheels are at the front of the carriage. They do not actually contact the slides unless the rear of the carriage is levered up a few millimetres, to assist with rolling the gun down to the firing position.
They are constructed of bronze.
On my model, the gap between the wheels and the slide would be about 0.3mm.
Today I attached the wheel brackets to the carriage cheeks (the sides of the carriage).
I had deliberately made them with a slightly large diameter, knowing that I would need to reduce the diameters after they had been fitted.
This is how I reduced the diameters…..
…on a belt sander, holding the oiled shaft in my fingers and using my thumbnail to hold the wheels in position. After a few seconds sanding, and being careful not to sand my fingers, I tried the wheels on the carriage, rolling it up and down the slide. That was repeated multiple times until the wheels were just clear of the metal slides.
The single axle will be replaced by more authentic appearing separate axles with dome heads and pins. The brackets will be let into rebates in the carriage cheeks, and tapered in their upper halves.
The Armstrong 80pr cannon on the dwarf carriage and wooden traversing platform, slides wood on metal slides. But, when the carriage and its heavy barrel (4+ tons) are returned to the firing position, there are two small bronze wheels to make the return easier.
Two strong gunners lever the rear of the carriage and barrel slightly, so the two small wheels at the front of the carriage take some of the weight, and the carriage runs forward. In fact, the return was a bit uncontrolled, so a rope was added to the rear of the carriage, thrown around the bollard at the rear of the slide, and a third gunner added some control to the return.
Today I made the 1:10 scale wheels. They are 20mm diameter, and 10mm wide. 13mm wide if the hubs are included. I spent a couple of hours with the design. And another couple experimenting with various CNC processes. Not many photos of all of this I am afraid. I learned some new V Carve Pro commands, including nesting commands using the same milling cutter, but there was some trial and error. The first two wheels took a couple of hours. The final two took only 30″.
The original wheels, and brackets.The brackets are partially recessed into the carriage cheeks. The wheels do not contact the slides unless the rear of the carriage is levered up slightly.A wheel, and brackets ready to be fitted to the carriage. The dished section was milled with a ball nose cutter.I will fit them next workshop session. The brackets need a lengthy chamfer first, as per the second photograph.
NB. these parts are not finished. Sharp edges remain. I will probably put them in the gemstone tumbler to smooth the edges.
Today I CNC milled the cams. And silver soldered them to the bearings.
The same process as making the bearings in the previous post. But much smaller.Silver soldered. Hebel base and brass block at rear to stop the parts blowing away.Magnified +++.The handle was cnc’d, but I made a mistake with the dimensions, so made another one. That is easily done with CNC. The tabs are cut with side cutters.Pins are fixed in the 4 holes around the pivot, and a “rope” 2mm diameter in the end hole. I will turn the handle over to hide the distal ding. The marks are the limits of handle travel, limited by the carriage transoms.
PS. A few days later. In a fit of perfectionistic idiocy I removed the bronze cams, and replaced them with steel ones. The originals were iron. The pins which pushed on the cams were also steel. That took about 3 hours, but now I can sleep easy.
And by the way, the compressor was working perfectly when finished. But a few days later, with a change in the weather, it is not applying enough pressure to the slides. That is the problem with articles made from wood….. they expand in humid weather, and shrink in dry weather. Dimensions changes of 3% are common, across the grain. It was probably one reason the wooden compressors were abandoned in favour of Elsworth iron compressors, and hydraulic mechanisms.
Making scale model components probably takes as much time as making full size ones. Well, with some exceptions. In each part of the compressor for example, there are as many measuring, set-up and machining actions in the model as in the full size part. Finding dropped tiny parts would take as much time as the (considerable) manhandling of the heavy full size ones IMO.
Yesterday for example, I spent about 3 hours deciding how to attach the compressor support pieces, cutting, machining, drilling and tapping the holes, then fitting them.
I use brass or bronze or stainless steel wherever possible. Not always the same as the original, but I don’t want my miniature to end up in the same condition as the originals in another 150 years. The brass tabs were placed as close as possible to the corners, but avoiding the long bolts holding the leaves together.The underside of the compressor. 10BA bolts. Wood gets grubby in the workshop. It will require a good solvent cleanup before finishing.To demonstrate the compressor location. It sits on the metal slides, and between the cheeks and cross pieces (transoms) of the carriage.The Smith’s Elevating Screw is finally complete. Here showing the pins which engage with the gear to turn the screw. The handle spins freely on the screw shaft. The hemispherical top sits in a corresponding hole in the bed plate. I am satisfied with this interpretation of the limited information available about the Smith’s Screw.
A very pleasant drive to Warrnambool yesterday, and re-inspection of the very rare compressor which was the recoil arrestor for the LowMoor 68pr cannon. And probably for all guns on the same carriage and platform, including the Armstrong 80pr RML’s at Elsternwick, Queenscliff, etc which I am currently modelling.
This is the 1861 compressor. 2 elm wood pieces, plus a repair on the right, all splits, cracks, rot and rust, and rather fragile. 4″ thick. Possibly the only one of its type still in existence. The central bronze elliptical bearing shell halves are in good condition. The iron pieces riveted to the bearing shells are rusted, but fairly intact. The rectangular pieces in the corners rest on the inclined platform slides. The central iron presumed elliptical post and its handle are missing.
I wanted to closely examine the iron riveted pieces closely to check my theory that the short straight sections are the parts which acted as the cams to close the gap between wooden leaves and release the friction from the braking action. Unfortunately the rust concealed any such evidence. But I still believe that was the purpose of these iron pieces.
So, today, I commenced making a 1:10 scale model of the compressor to fit to my miniature cannon.
The bronze bearings and attached iron cams protrude above the surface of the wooden leaves.
At 1:10 scale the bronze bearings would be less than 1mm thick. How to make them?
I CNC milled them from some gunmetal hex bar, then parted them from the bar in the lathe. I had previously made the wood leaves, and CNC’d the elliptical hole to fit the bearings. I don’t have any elliptical drill bits.… and they fitted nicely. The original bearings were screwed to the wood leaves. I intend to use Loctite. The originals were made of elm. I used a close grained Victorian Mountain Ash.
I milled the steel elliptical post from silver steel. Yes, CNC’d.
Steel post, threaded to eventually fasten the handle with pins to move the cam pieces. Handle not yet made. The pieces all fit well. The screw is temporary.
Another workshop session require to make the iron cams and the handle with pins.
After milling the rebates in the wood, I attached the bracket with the brass screws, and sanded them flat with the surfaces. Most of the strain will be on the steel screws. The brass screws are screwed and Loctited into place.
Then drilled and tapped the wood for the BA10 stainless steel bolts. It is fairly close to the original fastening method.
It took 4+ hours.
A short post. Tomorrow I am visiting the Flagstaff Hill Museum at Warrnambool, 2.5 hrs each way, to get some final details about the wooden recoil brake, the “compressor”. There is a problem with my CAD drawing of the compressor, and I am hoping that close inspection and measurements will answer my query. I will be accompanied by my expert friend Stuart for some extra perspective. The compressor will be the final substantial component to make for this model.
This is one of the few parts required to finish the model Armstrong 80pr RML cannon on a wooden carriage and traversing platform.
It is the ring which is attached to the rear of the carriage, used to control the descent of the carriage and barrel down the slide to the firing position, with a rope attached to the ring. The bracket is buried within the rear transom, and extends underneath the transom with more screws and bolts.I cut the bracket pieces from 2mm flat brass strip, using a 3mm diameter endmill.
The issue in silver soldering the pieces together was that they are quite small, about the size of my little fingernail, joined at an 95º angle, with the ring also soldered in place in the same heating session. And I did not want solder getting into those 1.6mm diameter holes.
So I screwed the angle pieces to a block of hardwood which had a 95º angle, having fluxed the edges carefully to exclude the flux from the tiny holes. I would have added typists white-out if I could have found it.
I knew that the wood would catch on fire with the soldering torch, but hoped that it would retain its basic shape until the solder solidified. The steel on top was to hold the ring in position during soldering. If the method did not work I figured that I could make an aluminium shape to replace the wood.
After soldering, I put out the fire by dunking the assembly in a bucket of water.
And it cleaned up quite well. Now to carve rebates in the transom so the bracket sits flush with the wood surfaces.
The circular cutout is to allow the end of the Smith’s Screw to protrude under the transom.
Not much to show for several hours in the workshop, but it’s better than working. And best of all the method was successful.
Another hot summer day today, so I arrived at my workshop early, before the heat set in.
First I drilled a 1.5mm hole through the Smith’s screw yoke and bracket, for the pin which completes the hinge mechanism which engages and disengages the screw handle. Sounds simple? Well, actually, my intention was insert a 1.0 mm pin, but the first drill bit broke. Now why didn’t I make that sensitive drill press when I first considered it?
So I had to disassemble the parts, and grub and poke around with a fine tungsten probe until all of the bits were out. Then set it up and drill it again. Used a 10BA bolt and nut as the hinge pin.
Then silver soldered some 1mm old drill bits into the previously drilled pin holes as the driving pins for the screw gear.
Parts fluxed, ready for heat and silver solder. I use 50% silver, with cadmium for these tiny parts. After soldering, a quench in water, brief soak in sulphuric acid to remove any remaining flux, another water wash, then the drill bits are cut to length, and tidied up. Why did I use drill bits? Because they were the only drill rod/silver steel which I had in this diameter, and it is a good use for blunt drill bits.
By this time the day was really heating up.
So, I threaded at 2.5mm some 3mm brass rod, then heated the sections where I needed to apply the bends, and made the handle. Also form turned the hemispherical head using a 2mm radius rounding over milling cutter on the lathe as described in a recent post.
The threaded post length might need to be adjusted, because I made it slightly longer than thought necessary. I have some spare length at both ends if necessary to adjust.
In position. It works even though I still need to fix the gear to the threaded post, and fix the truncated cone at the top to the post. I intend to use Loctite.and I have yet to machine a hemispherical cavity to the underside of the iron (brass actually) bed.
Another half day workshop session saw some more small parts made for the Smith’s Elevating Screw at ~1:10 scale. As close to 1:10 scale as possible, but I decided to make the parts about 20% bigger than the dimensions I scaled off the poor quality drawing, to fit with small drill bits and end mills in the tiny end of the range. The smallest end mill which I used was 1.5mm diameter!
CNC Drilling the gullets in the gear with a 1.6mm drill bit, after turning the OD of 15.9mm. I made 2 of these parts, just in case.
This is the gear after completing the gullets with the 1.5mm end mill. 3000rpm, 0.5mm depth of cut, 30mm/min feed rate. (metal working is not great for hand beauty)
The Smith’s Screw square thread, yet to have a hemispherical head turned after sawing off the excess length, the brass half cylinder nut, the gear, the yoke and the shaft bracket. A hinge pin will be inserted first, then some relieving of the hinge edges. The yoke and shaft bracket were CNC’d from 3.5mm brass plate.and a handle to be added, and a restraining collar. Oh, and the 3 steel driving pins to be silver soldered in the yoke holes.
One more session should see the Smith’s Elevating Screw completed.
Did you notice that I have modified 6 details since drawing this?
Unless you have one of these resin printers I suggest that you close this post and look at something of greater interest.
One problem which I encountered with my AnyCubic Mono X 3D printer, was that it was often difficult to separate the print from the base without damaging the print due to excessive adhesion. I have changed the print settings to reduce the initial layer UV exposures to 16 seconds which has helped somewhat, but I decided to try using a magnetic plate. A magnetic plate worked really well on my filament printer, and I was hoping for a similar result on the resin printer.
So I purchased another aluminium base, and a 3M stick on magnetic surface. I could have used the original base, but that would have committed me to using only the magnetic plate surface. Having a second base leaves my options open.
The base which I purchased looked similar to the original, but I noticed that it was not flat. In fact it had a concavity of approximately 0.25mm over its length. Also, it was missing the rather distinctive AnyCubic patterning in the aluminium surface which I think was a reason for the high adhesiveness of the original plate.
So I spent about an hour sanding the base with 200g sandpaper on a surface plate, and finishing with 600g emery paper, also on the surface plate. After that I could not pass a 0.003″ feeler gauge under the edges of the plate. Not dead flat, but should be close enough.
The surface plate, emery paper, and printing plate.
I had watched YouTube accounts of other AnyCubic Mono X owners using these magnetic plates, and finding that the extra thickness caused by the magnetic plate (2.6mm) was too great for the levelling mechanism to function. Various work arounds have been used, including moving the position sensor, and 3D printing a spacer for the sensor, to gain the extra 2.6mm.
My solution? With a milling machine waiting to be used?
The printing plate bracket.
I milled the screw slots 3mm longer, and milled 3mm deep rebates along the edges as shown above. Admittedly, the same result could have been achieved with drilling and filing.
The cost? $AUD40 for the new printer plate, and about the same for the magnetic surface.
When the Armstrong 80pr barrel was mounted on a wooden carriage, the angle of elevation was fixed by the weight of the breech resting on a wooden wedge shaped item called a quoin. The quoin was marked with graduations to correspond with degrees of elevation.
To change the elevation, the breech of the barrel was levered using the steps of the carriage cheeks as a fulcrum and the quoin position was adjusted. The trunnions of the barrel were placed forward of the centre of gravity, and the weight that gunners had to lever was considerable.
The angle of the wedge of the quoin was important. Too great and it could shoot out backwards when the gun was fired, and risk injury to the gunners. Too shallow would make it too long or restrict the range of elevations.
Fine adjustment of the angle of elevation was managed with a screw mechanism called a Smith’s Screw, introduced ~1860.
My CAD drawing. The bronze base is reasonably accurate. The other parts are based on the diagram below, or inferred.
I am currently making a Smith’s Screw for my 1:10 model. I must rely on old drawings of the Smith’s screw, because I have been unable to find a single example of a museum specimen anywhere. And the Smith’s Screws have been removed from all of the existing original wooden carriages. When not in use for actual firing, the screw and handle and gears were removed and placed in storage, along with the gun sights. Who knows what happened to the Smith’s screws when the guns became obsolete.
Some dimensions can be inferred from the base, which sometimes does remain in the original carriage, and from the rounded cavity in the iron pivoting slab which the screw supported. There are very few original wooden carriages, and I have been fortunate to find a handful in Victoria. I am told that they are exceptionally rare in UK, having been broken up when the guns became obsolete. Unfortunately, the drawings which I have found are of poor reproductive quality, and have no dimensions apart from the diameter of the screw (2.25″).
Smith’s Screw on the right.
One design feature of which I am reasonably certain is that the screw itself would have been a square thread. Acme threads were introduced in 1894, and replaced square threads in most applications because they were easier and cheaper to manufacture, stronger, and when the nut became worn it could be adjusted to take up the wear. Square thread nuts had to replaced when they became worn. The only downside to the Acme threads was that there was more lateral pressure on the nut, and greater friction and resistance to movement.
29º included angle is “Acme”, 30º is “trapezoidal”Acme or square? Can be difficult to decide. Will it make any difference at 6mm diameter? It certainly makes a difference when making the thread.
So, I have been on a learning exercise to make a square thread. So far I have had about 6 failures. Maybe more. I can see why the square threads are more expensive than the Acme threads.
I had decided to make a 5mm diameter screw. A bit smaller than the 1:10 scale of the 2.25″/57mm original. Actually, 6mm would have been closer. (thinking). It needed to be 1.5″/38mm long. The pitch is unknown, but I had a tungsten cutter which appeared to have been ground for just such a purpose, with a width of 0.8mm, and therefore a pitch of 1.6mm. So the cutter determined the pitch. I have a CNC lathe, so I could decide on any pitch without changing gears. For example I could choose a pitch of 1.6mm, or 1.61mm. Whatever. But to be a square thread the thread depth should equal half of the pitch.
The next problem was with my CNC threading software. Mach 3 has a simple threading “wizard”, and I tried it on my CNC self converted Chinese lathe, which works fine for most applications, but the lathe’s shortcomings (lack of toolpost rigidity mainly), and use of stainless steel rod, gave poor results, then caused the cutter to snap.
So I switched to Ezilathe. Several problems due to my inexperience with square threads vs. conventional 60º threads and a software bug, prompted several calls to the software author, who resolved all software issues without much ado. (thanks Stuart)
But, I was still not getting good results, so I tried my Boxford CNC lathe. It is a beautiful little lathe, but with one serious fault. The tailstock is horrible to use. It is a real fiddle to install, limits the movements of the cross slide/toolpost, and worst of all I did not have a suitable morse 2 centre. I suppose that I should have taken time out and made a dead centre. But I didn’t. Wanting to see some results I pressed on.
With Ezilathe now working well, I decided to practice the square threading using 5mm brass rod. Without a tailstock the 40mm protrusion from the chuck was too much, and the rod bent. Sharpened the cutter, used minute depth of cut (0.02mm), and reduced the protrusion to 22mm, to make a 20mm long thread. Ahhhh. Looking better.
Now to try it with the steel.
That also worked well! A very nice square thread 20mm long, and the rod barely deflected at all. Copious lubricant being brushed on at every pass. 300 rpm. 0.02mm DOC. Sharp cutter.
Now, the rod duly square threaded is required for the screw, but 20mm was a bit short. It really needs to be a minimum of 30mm of thread. 38mm would have been ideal. And I need a length for the screw itself, and another length to make a tap to thread the nut. So I tried a 30mm protrusion. And heard a “click” as the cutter snapped. I think that the deflection causing chatter was the cause. Or maybe the discolouration of that end of the steel indicated that I had used it previously during silver soldering. Maybe I had hardened it.
So I stopped there to lick my wounds, went home and slept on the problem.
Next session I will: 1. make a dead centre for the Boxford, to support longer stick out. 2. Use silver steel instead of stainless steel. It will harden better for the tap, and might turn a bit easier. 3. Use 6mm rod instead of 5mm. For extra rigidity. 4. Make the thread 5mm longer than essential, to keep the cutter clear of the tailstock. I will turn the diameter of the extra 5mm length, down to 5mm diameter, to minimise the impact of the cutter plunge.
Oh, and by the way, I have been making left hand threads. The Boxford has a rear toolpost, and I forgot to invert the cutter which is required to reverse the direction of the chuck to make a right hand thread. I do not know what handedness the original thread had. But right hand is more common generally.
And if all that still fails I will make Acme threads. They will be easier, and at the scale I doubt that most observers will pick the difference.
Next day, next workshop session.
I decided that tailstock support was essential, so I went to my Colchester 2500 Master lathe, and plugged in the 2mm pitch settings. Easy. The tailstock was introduced. I made some right hand threads, on 6mm silver steel, no problems. Just time consuming. Had to regrind the 1mm width cutters several times, but eventually I had 2 reasonable lengths of square thread. One for the Smith’s Screw on the cannon, and one to make a tapping tool.
I machined a taper on the tapping tool, then used a Dremel with grinding wheel to produce the reliefs. Heated the tool to dull red heat and plunged it in cold water. Then gave it some slow heat to anneal it. It was still able to be filed, so the hardening process had not worked well. But it was to be used for only one tapped brass nut, so I accepted it, and proceeded.
The tap. It will the first and last square tap I will ever make. My eyesight was just not good enough to accurately grind the reliefs.
Cutting the thread in the brass nut was not easy. I needed several revisions of the thread cutter, using the Dremel with a small grinding wheel.
This is the brass nut on the square thread steel. Not as tight as I would have liked, but OK. Useable. 6mm diameter. 2mm pitch.Fitting the nut to the base required some further relieving with the Dremel but there were still some tight spots, so I used a method from the past. Gumption.
Gumption is a kitchen cleanser which has a mild grinding action using rotten stone. It lasts only a few strokes, then disappears. But it worked brilliantly, and the nut now fits perfectly in the base. The excess Gumption just wipes or washes off.
So that was a day in the workshop. Not much to show. Maybe I should have spent the day with wine, women and song. It’s OK. SWMBO does not read these posts.
Next session to finish the threaded post with a hemispherical head. (just fantasising about the W, W, and S). Then the cog, handle and corresponding hole in the “iron” support.
This is my CAD drawing of a Smith’s screw, which was used for fine adjustment of the barrel elevation of cannons on wooden carriage/platforms. The pivoting nut sits in the base. The threaded shaft is turned by the cog near the top which is turned with the iron lever which has protruding pins.
I started this mechanism for the Armstrong 80pr gun model today, by making the bronze base.
There were 4 components of the base, which were joined with silver solder. I could have printed the whole base and cast it in bronze, but I had nothing else to cast so decided to fabricate it with basic machining.
The 4 components. The bearing surface is bronze, the rest are of brass.Squared up a lump of bronze, then used a ball nose cutter to make the rounded channel.Carved out the desired bit…And silver soldered the 4 components. Not very pretty at this point. But with some filing and sanding it finished looking quite respectable.
Then to machine a recess in the posterior transom.
I did not want to make a mistake here, so did an air cut to test the CNC programming. First a shallow cylinder, then a deeper rectangular hole.I spent an hour or so filing the part to make it fit into the recess. It was a neat fit, so pressed it into position.A match to hold the “iron” quoin support in position for the photo.
Next session to make the cylindrical nut with a 5mm acme thread, and the matching threaded post.
I have made an appointment to see the original compressor unit at Warrnambool in a week, so I am deferring making that final component until I have checked some dimensions.
Ageing eyes require stronger glasses, longer arms, and acceptance of less than perfect results. However, this fault was not due to my deteriorating eyesight, but poor judgement.
I was drilling screw holes in the trunnion bearers. The bearers were tightly held by the dome head bolts so I drilled the brass and the wood together, with the carriage held in the milling vice. Unfortunately it was not held well enough, and shifted, causing the above.
So, what to do? Start again and make a new trunnion bearer? That would take maybe half a day. Or just fill it?
Filling it with copper coloured epoxy was quick and simple. If anyone notices the filled hole I might remake the trunnion bearer one day.
In the photo above, note that I have made the gun sights.
Looks a bit rough at this magnification. 10BA locking screw. 2mm diameter shaft. I have never been able to see an actual original, but this pattern is based on an old diagram of a tangent sight of the period. The shaft would have been calibrated for distance. The front sight. The sights were installed for firing, and removed for storage. In order that they are not lost from the model I have glued them in position. The machining marks are a bit ugly, but consistent with the actual finish on the full size barrels.An interesting test. The trunnions bearers holding the weight of the barrel being held upside down.
The barrel trunnions sit in bronze bearings which are held in place with screws, and under the heads of the large carriage bolts shown above. Land based “garrison” guns, like the ones which I am currently modelling, often do not have trunnion caps, relying on the weight of the barrel and the slightly deeper bearings to keep the barrel in place during firing. Naval guns always had trunnion caps to avoid the “loose cannon” disaster on board warships.
The round pins under the flanges are actually rivets, placed with the intention of preventing splitting of the carriage wood in the trunnion region.
I had turned some bronze to size to fit the trunnions and the carriage cheek cut outs. Once before I had cut the entire trunnion bearing and its flanges from solid brass, but for this one I decided to cut the flanges from 1.6mm sheet, and silver solder them to the round section.
The first issue was how to cut off the unwanted top section.
I turned a mandrel from aluminium and pushed the bearing cylinders into place…
and marked the segment to be removed.
The cross definitely identifies the part to be removed.
and milled away the unwanted bits. The sacrificial aluminium mandrel prevents distortion from holding the thin cylinders in the milling vice.
checking that they will sit correctly….a rebate will be made in the carriage cheeks so the flanges sit flush with the cheek tops.
Then silver soldered the flanges using a mini oxy-propane torch. The soldering hearth is made of Hebel blocks, which are cut fairly flat and accurately. The back block is to prevent the light components from being blown out of position by the gas torch.
After some sanding on a flat surface, and a check of the parts on the trunnions to exclude distortion, all is looking good.
Next session I machined the rebates
Some shaping of the corners with a Dremel to fit the solder.The finished result.
And I have added some more eye bolts…
But there was a problem with the eye bolts in the platform…Nuts on the inside of the slides prevented full movements of the carriage. On the originals, these nuts were buried, with nothing protruding. So I had to cut some pockets on the insides of the slides. I had not anticipated this problem when I bolted and glued the platform, and I really did not want to break it apart to make the pockets.
So, to cut these pockets in this very tight space, I made a special tool. Fortunately there was a corresponding hole on the other slide.
The finished pocket with the buried nut.This cutter sits between the slides. After that, the 3mm driving rod is screwed into the base of the cutter through the other slide, and the pin at the cutting face is placed through the side to be cut. As you saw, it worked well. Mild steel, I did not bother hardening it, and it made the 4 cuts without any problems.A bit rough but it did the job well.
So that is where this job has progressed to. Still to be made are the Smith’s elevating screw, the compressor, the sights, the quoin. And then the surface finish.
The 80 pr muzzle loading cannon was supplied to the colonial government of Victoria on a wooden traversing platform with a 5º slope.
I assumed that the slope was the means of absorbing the recoil.
The later iron platforms (from about 1875) had a 4º slope and hydraulic recoil control.
But, I was recently informed that there was a wooden “compressor”, which acted as a primitive brake, to reduce the distance of the barrel and carriage recoil. And that there was a compressor at the Flagstaff Hill Museum, Warrnambool, Victoria.
In fact I had previously seen the compressor, but neither I, nor I suspect the museum staff, really understood then how the compressor functioned.
Using Victorian Collections photographs published on the web, my own photographs, information from “The Artillerest” Peter Webster, some old drawings of wooden carriages and platforms, and a Google book “British Smooth Bore Artillery” by David McConnell, and a fair bit of deduction, I think that I have finally worked it out.
Firstly, the Victorian Collections photographs…
The compressor sits between the slides, with the rectangular iron tabs resting on top of the slides.The elliptical central hole is filled with an iron elliptical post with a long handle attached to the top. When the handle is pulled backwards the cheeks are pushed outwards by 1/8″ 3.2mm, acting as a brake. The tapered iron bits had me stumped.My drawing of the compressor with the brake applied. From above. When the handle is pushed forward, the gap between the cheeks closes and the brake is released. The pins push on the tapered outer iron cams to ensure closure of the cheeks. Ahhhh!From below the compressor, with brake applied. The handle has a square drive in the square hole. A rope is tied in the distal handle hole.
Now to make one at 1:10 scale.
P.s. reader Jeff sent me some photos of a recoil control system used in 19th century USA, where a large metal screw clamp was utilised in these rifled muzzle loaders
I had a phone conversation with Peter Webster, “The Artillerist”, yesterday, after I emailed him about the recoil control compressor which I had photographed at Flagstaff Hill, Warrnambool.
the very rare compressor. The loose metal bits on top are not part of the compressor.
I could not see how it could fit into the carriage or slide of the LowMoor cannon, or how it functioned.
Peter, who has a passion for Australian garrison artillery, 1788-1950, and has encyclopaedic knowledge on the subject, had seen this object at Warrnambool almost 20 years ago, realised what it was, and subsequently wrote a report for the museum. The compressor is classified as being extremely rare, most having been removed from the guns, probably to remove the gun metal components for scrap.
Peter explained to me that the flat, rectangular compressor sat between the platform slides with the metal corner tabs resting on top of the slides and the centre join of the compressor located along the centre line between the slides. The front and rear surfaces fitted between the cross members of the carriage.
The central hole was almost vertical. The hole is elliptical, not round. Sitting in the hole was a neat fitting elliptical post, which had a handle which protruded out to the right hand side between the carriage and the slide. When the handle was pulled, the post rotated and increased the separation of the 2 halves of the compressor, pushing them against the sides of the slides, as a brake.
Peter was sure that all carriage/platforms of this type would have been fitted with these compressors, until the wooden structures were replaced with the iron types a decade or so later.
So clearly I will have to make a scale model of the compressor for my current model.
This is a modified version of the carriage and traversing platform. It is the best drawing I could locate which shows the compressor insitu. Note also the central pivot and its large cross beam, which is bolted to the slides with the vertical bolts I had wondered about at Elsternwick. Peter told me that the Elsternwick guns would originally have been fitted with pivots, but removed due to being damaged during firing.
Thought that you might be interested in some more photos relating to RML’s.
That barrel could be an 80pr Armstrong, 3 meters long, which would make the lathe about 8 meters long. Note the date, the taper cutting mechanism, and the fact that they did some external turning with the trunnion ring insitu. This is said to be the recoil controller from the wooden carriage/platform which is outside the Maritime Museum, Warrnambool. It is apparently an exceptionally rare item. Not on display. Shown to me because I asked questions about the cannon. I could not see how the recoil mechanism would have been fitted or functioned on the particular cannon. Picture of the Warrnambool cannon on its wooden carriage and platform follows. The loose metal objects on top are not related to the recoil mechanism.The preserved, protected, and unrestored condition is very useful for modelling. LowMoor 68pr SML. 1861.I have possibly shown this photo in a previous post. It is the 1866 80pr Armstrong RML on wooden carriage and platform at Fort Queenscliff, 30″ drive from my home. Missing the Smith Screw, sights and gunners side platforms, but otherwise in reasonably complete condition. No evidence of a rear gunners platform. Front left wheel bracket needs some attention. and just to complete the photo collection of 80pr’s on wooden carriages and platforms, I revisited the Elsternwick cannons recently to get some more measurements. Early evening photo. Note the bolts hanging under the slides. They do not exist in any of the old drawings or photos. Maybe this one had a pivot support originally. Some of the very early platforms did have pivots, but they were removed as being unnecessary, and liable to damage when the gun was fired. Also note that none of these guns had trunnion caps, which were considered unnecessary in garrison guns. The trunnions do however sit slightly deeper than half way in the carriage cut outs.For a bit of perspective I add this photo of manufacturing a 16″ barrel in WW2. USA factory.
We are having a La Nina summer. Relatively cool and wet. Humid. But, it is summer, and week long spells of over 30 degree centigrade days are expected, even in a “cool” summer. Today it will be 33c with high humidity, and those are not factors consistent with a pleasant workshop experience. So I will stay home and plan ahead how to make several components for the model Armstrong 80pr cannon on the wooden carriage and slide.
One item is the elevating mechanism for the 4 ton barrel. Several readers have helped with information about the mechanism, which I now believe to be a “Smith Elevating Screw” which adjusts the level of a heavy hinged iron bar, on which sits a wooden wedge called a “quoin”. The breech of the barrel sits on the quoin. The quoin is the coarse adjusting component, the screw is the fine adjusting mechanism.
This is the carriage and traversing platform which I am modelling at 1:10 scale. The barrel is an older smooth bore muzzle loader, but the dimensions of the carriage and platform seem identical to those of the 80pr Armstrongs at Elsternwick which I am modelling. The screw and quoin and iron bar are at the rear of the carriage.
Another 19th century drawing of the wooden carriage and platform, with a 110pr breech loading barrel. Also showing the Smith’s elevating screw.This is the only picture which I could find with any detail of the Smith Elevating Screw.….and this is a 1:9 miniature Smith Screw, made by Jefenry for his Armstrong 110pr breech loader, and whose videos I have shown in an older post. Those You Tube videos are really interesting to watch. Just do a search on “Jefenry”. These pictures are very useful to me. Thank you Jefenry!And finally, a couple of recent photos of progress on the model to date. The Smith’s Screw fits into a half cylindrical nut which sits in a bronze enclosure within the rear transom.
I needed to add some substantially strong rings to the slide of the Armstrong 80pr on the wooden chassis. These rings are the attachment points of the blocks and tackle which are used to point the cannon in the direction of fire. i.e. the traversing mechanism.
Scaling off photographs and drawings I determined that the rings had an o.d. of 100mm, and an i.d. of 50mm. i.e the material was about 25mm diameter.
I had made some rings for a previous project, and had some of the material left over…
But, when I cut off the coils to make the rings I decided that they looked too spindly.
So I annealed some thicker rod which was 2.5mm brass…
… and wound it around a 5mm steel post….….cut off the individual coils with heavy side cutters, and straightened them in the vice.Then positioned them on an aerated concrete block to some 3mm all-thread….and silver soldered the rings to the all- thread. The lump of steel is just to keep the bits in position during soldering.Drilled the slide beams after careful measuring, 3mm tapped as deep as possible, then completed the tapping through the 30mm beams with a long length of 3mm all-thread.Screwed the eye bolts into position, and locked the other end with square nuts. Eventually the square nuts will be buried in the beams.No where near finished, but looking more interesting with some bling bolted in place?
Just to remind you that this is what I am modelling, at 1:10 scale. An 80pr Armstrong rifled muzzle loader, on a wooden carriage and slide. This pair is at Hopetoun Gardens, Elsternwick, Victoria.
I had imagined that this wooden chassis would be a relatively simple, quick build. The following photos show what I have accomplished in the last 3 days.
The gunner’s platform, supported by steel angle iron brackets, and the wooden “bollard” (I do not know what it is really called) which is used to wind a rope, and control descent of the cannon carriage down the slide to its firing position. And the odd metal bent rod bracket with the loop. I do not know what its function is. Does a reader know?The underside. The gunner’s platform brackets were cut from some galvanised rectangular section tubing, then bent after heating with oxy-propane. Not perfect, but OK. The stainless steel bracket between the slides was cut from 1.5mm thick sheet and cold bent.
These little parts are very time consuming, but oddly satisfying to make.
And meanwhile, my friend Stuart has once again used his 30 watt fibre laser to engrave the barrel markings.
Top is Queen Victoria’s cypher, with the Order of the Garter motto. Then the site of the vent/touch hole (which will remain as a mark only), then the barrel proving marks, and then the weight of the barrel in hundred weights, quarter hundred weights, and pounds. (just over 4 tons). At bottom is a barrel centre mark. It lines up with another one on the muzzle.
On the left trunnion R.G.F. for Royal Gun Factory, the 24th barrel of this pattern made, and the year of manufacture. Some more polishing will improve the appearance and sharpness of the lettering.On the right trunnion, the barrel centre line (horizontal), and trunnion centre line. Again barrel number 24.And, this from reader Richard, who sent me this photo of an exquisite scale model studded projectile and trolley. Studs were prohibited from the Armstrong 80pr’s because they caused rapid wear of the bores.
Actually, the wooden slides were used on other British garrison cannons as well as Armstrongs. For example, at Flagstaff Hill, Warrnambool there is a 68pr LowMoor mounted on a wooden slide, which is identical to the slides used for the Elsternwick Armstrong 80pr’s. And I have a drawing of a breech loading 110pr which was also mounted on an almost identical slide. The only differences were in the carriages, and those differences were minor, depending on the diameter and weight of the various barrels.
So I have used measurements from several slides, located at Port Fairy, Warrnambool, and Elsternwick. The Warrnambool slide is unrestored and badly rotted in some places, allowing inspection of the interiors of the big longitudinal beams. The Elsternwick slides have been restored, painted, and have metal protective covers, which conceal details of the metal strips on the tops of the slides. The Port Fairy slides have been extensively and expertly restored.
And there are always compromises to be made when scaling down structures by a factor of 10. Fasteners for example are only approximately the scale dimensions.
Here are some pics of progress to date on the slide…
The metal strips are stainless steel. Not authentic but should polish nicely. 30 countersunk screws per side. I superglued the slides in position, then centre drilled, drilled and countersunk the holes. Getting the countersink depth was tricky and required a lot of trial and error on each hole. Then I filed any protruding bits of screws flush with the slide surface.
To shape the stainless steel strips, on Xmas Eve, I roughly bandsawed them to shape, then milled the edges to end up with 23mm wide strips, 480mm long. The steel is only 1mm thick, so holding it for milling required some planning. Guillotine or laser cutting would have been preferred, but not wanting to wait until mid January for a pro shop to cut it, I did it myself, using 2 bits of straight hardwood to hold the thin stock in 2 identical vices on the milling machine.
On one of the bits of hardwood I made a 23mm deep cut on a face of the wood, and rested the thin stainless steel on the lip thus formed. Then ran a sharp milling cutter along the surface of the wood, cutting the steel to size. That worked fairly well. As you can see, I removed about 10mm width of the steel in one run. Checked the dimensions, remounted the strip in the bits of wood, and finished the edge milling. Yes, I had to file the edges to remove the sharps. Drilling the fastener holes, after supergluing the strips into position. The large hole is as in the originals, to allow access to the wheel bracket bolts.The wheel brackets are finished, and bolted into position. Wherever possible I am using brass, bronze or stainless steel. A few more parts to be made and fitted, including carriage stops, a wooden bollard, gunners platform and tackle block rings. Then to decide about painting-finishing.The wheel brackets are attached by a bolt which passes right through the longitudinal beams, to be secured with a round nut at the top.
Today I turned the chassis wheels, and the axles, washers, and pins.
First I tried to turn the wheels from some stainless steel shaft, but it was too hard, and destroyed HSS and carbide tips.
So, I changed to some free machining steel. A lot nicer.
A steel wheel, stainless steel axle, and brass end washers.The washers have a curved face. I could have CNC’d the curve, but I used a method which had previously worked well. Using a milling bit, designed for milling a rounded edge. But works incredibly well when supported in the lathe toolpost.Then parting the washers.8 washers required. The lathe spindle had to be run in reverse. Quick, and excellent finish.
Then the axles were drilled for the retaining pin, and ground to length.
Next session in the workshop I will make the wheel bracket supporting bolts.
For my previous model Armstrong 80pr cannons I made the iron carriage and slides using metal casting of 3D printed PLA filament for the complex castings. The results were OK, but I was not satisfied with the surface finish.
So, I bought a resin printer, and I have been very impressed with the results of the resin prints.
But, to date, I have been unable to get any castable wax resin suitable for the resin printer, with which to make the bronze castings.
So, I decided to revert to traditional machining methods, using reductive technology. Milling, lathe, etc, removing brass chips from bar stock to end up with useable parts.
This is what I am trying to make at 1:10 scale.
The wheel bracket appears to be made of cast iron. Possibly the wheel also, but it was probably turned in a lathe.These are the brackets which I have milled and turned from 38mm brass bar stock. Not quite identical with the originals, but close enough I have decided.Billets cut to length, with an allowance for holding in chuck. OAL 50mm.The external shape was CNC’d.The wheel slot was cut with a 3.5 mm thick slotting saw. 3 cuts to get the full 9.5mm width. The axle holes were spotted and drilled.
Then, I pondered long about how to remove the 20mm of stock which was allowed for the chuck jaws. I realised, too late, that I should have allowed another 10mm or so, because the parting line leaves too little to be held in the lathe chuck while parting.
So, I came up with this work holding solution…..
I drilled the hole in the bracket which will eventually house the mounting bolt on the model. 5mm diameter. Then drilled a 5mm hole in a piece of scrap, and bolted the 2 pieces together.
Actually, 5mm allthread is not much to hold a 36mm diameter piece for parting. So the thread was nutted and lock-nutted at each end. And torqued as tightly as I dared.
Holding the bolted extension in the 3 jaw, then slowly parted off the bracket. I stopped at 7mm, so the bolt holding the parts together did not crush the parts together and jam the parting tool.Removed the bolt, and hacksawed the bracket from the bar. Then some belt sanding and finishing on a flat plate.
After parting the first part by hand winding the cross slide, I became more adventurous with the next three. Made sure that the gibs were tight, the carriage locked, and setting the spindle at 500rpm, used the power feed to do the parting automatically. With plenty of coolant-lubricant (my home made mixture of olive oil and kerosene.). But still finishing with a hacksaw.
With end result shown in photo 2. All good.
Next to make the wheels and axles from steel. Those brass bar offcuts will go into the “might be useful oneday” container.
So, I got a container of basic grey printer resin with my new Anycubic Mono X resin printer, and I have been learning the basics of resin printing. Lots to learn. Not like filament printing at all. Lots of failures, but getting there.
Almost at the point where I would like to make a metal casting, using the lost PLA/resin/wax method.
1 litre of basic grey resin costs about $AUD40.
On YouTube, the experts seem to be using special resins suitable for casting. For example Sirayatech Cast Resin. Costs about 3 times as much as the basic grey resin when postage from US, and taxes are added in. And about 6 times as much as filament on a weight basis.
But, I wondered, can basic grey resin be used for casting? It is MUCH cheaper.
So I performed a little experiment.
I placed two small PLA filament printed objects in the burn out oven, with a resin printed object of about the same size. And progressively turned up the temperatures.
On the left is a basic grey resin printed wheel bracket. Middle and right are filament printed PLA wheel and wheel bracket. All in the burnout oven. At 250ºc not much is happening. ( a quick door opening, photo, and door close.)At 350ºc the resin object looks unchanged. The 2 PLA objects are melting.Not a good photo, but at 430ºc the resin object is black, but retains its shape. The PLA objects have vapourised and disappeared.This is the resin printed bracket after 15-20″ at 450ºc. It has left a shell of carbonised material. The PLA printed objects have disappeared. You can still see the bracket shape in the ash.I let it cool down, and then crumbled it in my hand.
At the end of this simple test, I hesitate to title it an “experiment”, I have to conclude that basic grey printing resin is totally unsuitable for using as a “lost plastic” in metal casting. It leaves too much carbonised ash which would be incorporated into the melted bronze/aluminium.
OK. so I have ordered a litre of the expensive Sirayatech Cast resin.
Actually, I bought it myself. 71 years of experience has taught me that Santa has little clue what I really like. And although it was justified on the basis of being an Xmas present, it did not arrive until New Year’s Eve, thanks to Australia Post. It sat in a clearing facility for 10 days, about 5km from from my house. They were too busy to bring it the 5km. Maybe APO executives are still really pissed off at missing out on their Rolex watch bonuses this year, or whatever.
Anyway, it did finally arrive, and I enjoyed unboxing the bits, and reading the instructions.
IT is a resin printer. An Anycubic Mono X, which converts liquid into plastic objects, with an incredible degree of accuracy and surface detail. 0.05mm layers, which are invisible to my eyes.
On the left is a semi automatic alcohol washer, and an ultaviolet hardening light, which was strongly recommended by various users. After 2 days of use, I am SO glad that I paid the extra $$ for it.
So, why have I moved from a filament 3D printer, to a resin based printer? And paid over $AUD1000 for the gear? (if I had waited until after Xmas I would have got the gear for $100-150 less).
Well, the promise of greater surface detail, absence of visible printing lines, waiting hours rather than days for prints to finish for starters. And it is newer technology, which usually means better. But not always. And the fact that several johnsmachines.com readers have recommended the technology for my cannon parts was quite influential. (thanks guys! You were right.)
There are a few downsides, compared with filament printing.
The liquid resin does have a chemical odour, a bit like rotting fruit, but frankly, it is not too bad. Even SWMBO has not objected to my initial prints being conducted on our breakfast table.
And the resin is said to be toxic. Masks, gloves etc recommended. But I wear neither. I do wash my hands frequently, and I wipe any drops/spills quickly. If I start twitching or talking rubbish or scratching a rash, you will know why.
And the maximum print size is smaller than possible from my filament printer. That had a maximum print size of 300x300x400mm. The MonoX resin printer has a maximum print size of 200x125x245mm. That means that any larger models will need to be split into 2 or pieces, and the parts joined later. But the parts are so accurate, that joining them to make larger models is a real possibility. Bigger resin printers are available, but not at this entry level price.
Resin printing is a bit messy. And cleanliness is essential to get good results and to prevent damage to the machine components. So there are a lot of paper towels, tissues, and alcohol. And I mean 99% Isopropyl Alcohol. I bought 1 litre from Bunnings which cost $AUD29, only to discover that the cleaning machine requires 8 litres. I quickly discovered a firm which sells 20 litres for $AUD100 posted, and bought a container (at $5 per litre).
And what do I have to show you so far?
Well, this is the standard test print. It worked at the first attempt. It is quite small, and I used the default settings. Note: no visible printing lines, no lumps or bumps or support marks. Pretty good!
Then, I had a few frustrating failures. Parts which I had designed, refused to print properly. So I went online to the MonoX users group on Facebook, and I got immediate helpful advice, which did not appear in the official operators manual.
For example, my prints were so strongly attached to the build plate, that I had to destroy them to get them off.
The advice? 1. freeze the build plate and attached parts in the freezer for 30″, then heat them under hot water. They separated easily. 2. reduce the intensity and duration of the UV light to 80%, and 20 seconds (rather than the default 40 seconds). Problem solved.
Test prints, showing incredibly fine detail. And showing that 2 second burst of UV is optimal.The level of detail is incredible. The fuzziness is my camera, not the print.
I am currently printing a cannon wheel bracket, as a test. With 1mm wall thickness. I am not interested in making plastic parts, except to use them to cast bronze or aluminium parts from them. The next test is to burn them in the potters oven to see how much ash remains.
Photo to be added…..
First actual part! 36mm diameter, 1mm thick walls. Drain holes added will be plugged with wax before burn out and casting. How perfect is that surface? (it is a wheel bracket for a wooden slide under an 80pr RML Armstrong cannon.)
This is what the casting looked like after I had removed most of the investment, and turned a flat surface on the top of the casting.
I was surprised that the levering pins, and the big thread came out much better than the simpler flat surfaces. That might be because I had concentrated on those areas with the painted on investment slurry. And also because that end was at the bottom of the pour. That end got the first, most liquid melt, and the pressure of the melt above.
Turning the ragged end where the bronze was short.It IS sort of interesting, no?
Having decided that my casting equipment is inadequate for this this size and weight object, I do not intend to have another attempt at making a 1:10 bronze Ottoman bombard. Plus, even this sad 3/4 complete component is VERY heavy. I would not enjoy carrying the full size 1:10 model.
The only question remains, what will I do with the above failure? It could join my gallery of failed parts (like the crankshaft of the triple expansion engine, which had a single incorrect dimension). It is useful to occasionally survey this gallery. It does motivate me to measure twice, cut once. Or it could become a very heavy and expensive door stop. Or I could drill out the bore and use it as a specimen flower vase. Or I could cut it up, and use the bronze in future projects. Maybe I will just sit on the decision for a while, unless any readers have any persuasive suggestions.
I am reminded of one of my late father’s aphorisms. “He (or she) who never made a mistake, has never made anything”.
This project was put aside when I broke some ribs unloading the melting furnace which I had borrowed. Each of the 2 halves of the bombard weighed about 8 tonnes in the original, and in my model will weigh about 8 kg each.
These 8 kg parts will be the biggest which I have attempted to cast.
I am using the lost PLA method, having 3D printed the parts in PLA.
Today I attached the PLA breech to a PLA pouring funnel (also 3D printed), and poured the investment medium around the part in a 5″ steel cylinder.
First I repaired the PLA part, where it was a bit ragged. Poured some melted wax where there was a deficiency due to unsupported overhang during the 3D printing process. I deliberately overfilled the area with wax. The bronze in that area will require some turning to get the eventual correct thickness. Melted the wax with a soldering iron.Glued the breech to the 3D printed funnel, also using melted wax. All of the PLA will melt and burn out during the “burnout” process in the potters oven. That is a lot of PLA to burn out, so the windows will be open.
In order to minimise the possibility of air bubbles sticking to surfaces and corners, I painted the entire model with investment, before positioning it in the casting cylinder, and filling it with investment slurry. It will set overnight, and I will commence the burnout in the morning.
Fingers crossed for the pour late tomorrow afternoon.
It is now the next evening. I am despondent.
I woke early, and when I arrived at the workshop at 7:30am turned on the potters oven, and placed the cylinder containing the PLA model and investment medium inside. (Problem #1.) The cylinder was too big to sit vertically or horizontally, so I placed it diagonally. It was awkward, and I was concerned that the bore piece, being supported only at one end, might break free. It did. (Problem #2.) Started the burnout cycle at 250ºc, slowly increasing to 750ºc over 8 hours.
While that was happening I set up the melting furnace, gas cylinders (3 of them), tongs, bucket of water, face masks, gloves, aluminised apron, etc outside. It was going to be a warm day. Unfortunately it was also windy. Not ideal.
The furnace (centre), gas cylinders rear, dry sand tray front. Bronze ingots weigh 12kg. I had predicted that the casting would weigh 10kg.
Stuart arrived, and he checked his furnace. We lit it to pre warm the furnace and crucible. (Problem #3.) The crucible fitted in the furnace, with little space to spare. Just enough for the crucible with its tongs to fit. Stuart commented that it looked very big. It was, I answered “a 14kg crucible”. When the 12kg of bronze eventually melted it only half filled the crucible. It was not the size which I had ordered. It was too big, and restricted the gas flame, reducing its effectiveness. The melting phase required 3 hours! Much too long. (Problem #4.) (PPS. note added 23 Dec. I checked the dimensions of the crucible. It is a 30kg crucible!!! No wonder it was too big for the furnace! I had ordered and paid for a 14kg crucible. No wonder it was too big for the furnace. I should have checked before using it.)
The crucible has to sit on the furnace floor, reducing the heat exchange surface area, and narrow space on the sides restricting the flame volume.
Then it appeared that the flame was not as fierce as Stuart expected. The gas was piped from 2 cylinders, and one was not icing up as expected. It was close to full. Why was the gas not coming through? Could there be a ball valve somewhere in the system? Later we discovered that the pipe from that cylinder worked in only one direction because there was indeed a hidden one way valve. There was no direction arrow. (Problem #5.)
So, when we did get to the pour, and discovered the central core broken free (#1),
I inverted the now red hot cylinder to shake the core free. I calculated that the bore would fill with bronze and need drilling later. But would there be enough molten bronze to fill the cavity? I had allowed 1.5-2kg extra bronze to cope with unexpected contingencies but this would be cutting things fine.
So, we did the pour. There was a LOT of slag, possibly due to the slow melt. The molten bronze seemed to pour OK, and it filled the mold and the central bore. But it stopped about 3 cm from the top. Bummer!. Not enough bronze. Oh well. A learning experience.
I have washed and scraped off most of the investment. Oh Dear. A total failure. But, the threads were OK, so not a total failure. The worst area was the middle section which I had not painted with investment slurry prior to the the investment pour. I think that the PLA must not have been water tight, leading to the moth eaten appearance.
And worst of all….
It is only half the weight of the cannon, and it is just too bloody heavy!
I could fix the mistakes, reprint the part, and recast it.
But, you know what? I am not going to. The biggest issue is that even if I am able to fix all of the problems, and get a good result, it will be too heavy to move around. It will be too heavy to use even as a door stop. Hmm. Maybe I will clean up the failure and use it as a heavy door stop. Either that, or cut it up and reuse the bronze in the next casting projects, which will be much smaller!
This will be another failed, abandoned project to add to the list. (Chess pieces, etc). Oh well. Live and learn.
(it does cause me to appreciate the Ottoman cannon makers of 1465 who cast these parts with wood fires, where each component weighed over 8 tonnes!)
“The Artillerist”, Peter Webster is a Sydney based expert on historic Australian artillery. So I contacted Peter to see if he could explain how the 4 ton barrel of the Armstrong 80pr was elevated when it was mounted on the wooden carriage and slide.
Peter explained in detail that there was a screw sitting in a gunmetal nut which raised an iron bar on which the breech of the barrel rested. If more depression of the barrel was required, a wooden wedge (quoin) was inserted between the barrel and the iron bar. Peter had seen this arrangement on a cannon at Fort Queenscliff.
Several other readers have sent me diagrams from old publications of the setup, and I sincerely thank those readers for their help. Here is one of the diagrams.
Even though the barrel is different from my Armstrong 80pr, the dimensions of the platform match precisely. And the elevating screw and the quoin show as dotted lines fairly clearly.
I could have made the model screw and quoin from these details, but I decided to visit the Queenscliff Fort to see them for myself. Queenscliff is only a 30″ drive away. It has been Covid closed to visitors for almost 2 years, but had reopened very recently. So off I went today.
The fort was built in the second half of the 19th century to guard Port Phillip Bay heads from the French, the Russians, and even the Americans(!). At that time Victoria was wealthy from the gold rush, and the authorities were worried about a raid to steal gold which was stored in Melbourne banks and the Treasury. The land walls of the fort were surrounded by a deep dry moat. The large black powder guns faced the sea. The big guns were fired in anger only twice. First at the Pfalz, German steamer trying to escape Port Phillip Bay at the declaration of WW1. The “warning shot” almost hit the bow of the ship. Then there was a confrontation between the Australian pilot and the German captain. And the ship turned around, was commandeered, and was later used as a troop transport to take Australian soldiers to Gallipoli. The German crew were interned for the duration of the war. Astoundingly, the same gun was the first one to fire a shot in WW2, at least by Australians. But that was at an Australian ship which did not identify itself properly, so was a bit less glorious.
The 1.5 hr tour included the cells, the magazines, the remaining guns, the lighthouses, the museum.
Another interesting story which I had never previously heard, was from WW2, 1942. An aeroplane was launched from a Japanese submarine in Bass Strait. The plane flew around Port Phillip Bay, taking aerial reconnaisance photographs. It was spotted from Fort Queenscliff, but by the time it was realised to be the enemy, it had gone. Telephone calls to the Laverton airforce base were similarly unsuccessful in raising a response in time. The plane completed its mission and was picked up by the submarine. The pilot visited Australia after the war and related the story, and showed photographs. Needless to say, the Australian population was not informed until many years later. Google showed this article…https://www.ozatwar.com/japrecce/recce02.htm.
This lighthouse is still in use. Lighthouses are usually painted white, but this is one of only 3 black lighthouses in the world (?). Wonderfull stone masonry. Basalt.The unusual “disappearing” gun. An Armstrong 8″ RBL. Manually loaded, it could fire 3 rounds per minute!Similar mechanism, smaller gun.The museum had many interesting pictures and exhibits. This one is the gunners loading a 10″ rifled muzzle loader. Taken in 1880.Do you recognise the young lieutenant sitting right front? It is Australia’s most famous soldier. The son of German Jewish immigrants. He was the only soldier knighted by a British monarch on the battlefield, in 200 years. Later General Sir John Monash. He was in charge of the Queenscliff artillery in the 1890’s.A famous rifle. Lee Enfield.This had particular interest to me.
After the tour had finished I was quite disappointed not to have seen the gun and wooden carriage indicated by Peter Webster. So I asked the volunteer guide about it. She kindly introduced me to the gun expert at the museum. He took me to the only gun which matched the description, away from the tourist areas.
That’s me, next to the 80pr Armstrong rifled muzzle loader on a wooden carriage and slide.
Bummer! The elevating mechanism is missing, replaced by a wooden prop which was used when the gun was not in use.
Working with wood. It is quite nice to get back into the woodworking. And slightly daunting. Those saws can remove a finger or a limb in an instant of inattention. I use a 12″ radial arm saw, and an 18″ bandsaw. Somehow, the woodworking tools seem more dangerous than the mill or lathe. However, having seen videos and pictures of metal working lathe accidents, where an arm was ripped off at the shoulder, and similar, I know that they are ALL dangerous. At the time of writing I still have all of my bits.
At 1:10 scale, the wooden beams which form the base for the slides are 488mm long, and 30x30mm square section. They have a 5º slope back down to front.
I am using Victorian mountain ash, a pale, tight grained hardwood, and I happen to have some offcuts in my hoardings.
The wood is thicknessed to size, and the ends cut at 5º on the radial arm saw, which I bought about 45 years ago. Back then, B&D/DeWalt was considered a quality brand. I have previously decided which faces will be top and sides, depending on appearances.checking cuts for squareness at the correct angle.And today I used the CNC mill to cut out the carriage sides. 15mm mountain ash. The holes were drilled first, then brass pins hammered into the ash and the sacrificial base. Then the outside shape routed with a 6mm metalworking endmill. Some sharp internal corners will need to be filed or cut later.I use a high speed spindle to do the routing at ~10,000 rpm.Propping some bits together to get an idea of the size. The barrel is 3D printed plastic.
Oh. And some really useful woodworking tools which I bought from Banggood last year, and used for the first time on this project. They are laser cut spring steel, with holes and slots at 1mm and 0.25mm intervals, and a propelling pencil for marking. Accurate by woodworking standards, and they work really well, and were not overly expensive ($15-20 from memory).
And another bit of technology which I find useful with this project….
This is a plan of a 110pr Breech loader sitting on a wooden slide and carriage. I think that it is the one which was modelled by Jefenry which appeared in the video from my post of a day or two ago. On close inspection, it appears almost identical to the slide and carriage for my Armstrong 80pr. The width is different, due to the larger diameter of the breech loader barrel.
By fiddling with the magnification settings on our printer, I was able to print the plan on A3 paper, at a scale of 1:2 of my 1:10 model. The plan is quite accurate, allowing me to measure off dimensions of the components, angles and so on. This has been really useful.
Note that the wooden assembly is held together with large nutted bolts. And mortise/tenon joints as revealed by the Warrnambool LowMoor cannon. I will use bolts, and brass dowels, because MT joints are fiddly, difficult to make accurately, and will not be visible.
This is the video which I shot at the Flagstaff Hill Maritime Museum of the LowMoor 68pr cannon on an original teak wooden slide and carriage. It focusses on structural aspects, which I can review when I am building the model. It will probably be boring for most viewers, but I am posting it in case it is useful or interesting to some.
The cannon is actually located outside the front entrance of the museum. On this occasion I did not go through the museum, but can highly recommend it for many fascinating exhibits, including the Armstrong 80pr RML cannons, artefacts from the tragic wreck of the “Loch Ard” especially the beautiful ceramic peacock, and the recreated colonial village. It is well worth visiting.
When I sat down at the computer to draw up plans for the wooden chassis using the dimensions and photos I had obtained at Elsternwick, I realised that I needed some extra details. Some measurements I had just forgotten to take. And some details were not visible due to the protective covers on the Elsternwick cannons.
But, I remembered that there was a wooden chassis at the Maritime Museum, Warrnambool, and that it has not been restored. In fact it was an original teak slide and carriage, supporting an older smooth bore 68lb muzzle loader. I seemed to recall that the slides had rotted away to some extent, and that might reveal how the transverse beams were joined to the long slides, details that I had not been able to determine at Elsternwick. Being an older cannon, the slide and carriage might have been different from those at Elsternwick, but I decided to make the 2.5hr drive and check it out. 30 minutes further on were the restored wooden chasses at Port Fairy, so I decided to make a day of it.
The barrel is a 68pr Low Moor, smooth bore. The slide and carriage are unrestored teak, which is quite rare in the world. When I ran a tape measure over it, the dimensions were IDENTICAL to the Elsternwick cannons, despite the different barrels, which are 80pr Armstrong RML’s.
So I was able to obtain the missing measurements, and to see that the transverse beams were joined to the long slide beams with large mortise and tenon joints.
However I was still puzzled by the barrel elevation mechanism. Was it a quoin (wooden wedge), or a screw mechanism? Or possibly both? And if both, why?
The barrel support on one of the wooden carriages at Port Fairy. The black beam is iron, hinged at the front transom. Quite heavy. The triangular vertical prop is wood. This arrangement is almost identical to those at Elsternwick. This arrangement did not make sense to me.
But, when I checked my blog at home that night, several readers from Australia and USA/Canada had provided references which described the mechanism. Thanks Jefenry, David and Richard. (and Australian expert, “the Artillerist” Peter Webster).
This is a rifled breech loader of similar vintage, and probably identical slide and almost identical carriage design. Note the barrel elevating mechanism.
The barrel elevating mechanism is a large screw with the nut in the cross beam (the rear transom), which supports the hinged iron beam, and above that is a wooden wedge (quoin). Apparently the screw was for fine adjustments and the quoin for larger adjustments. I am reasonably convinced that was the arrangement of the Elsternwick 80pr Armstrong RML’s too.
In the diagram above note the roller/lever. That was used to lever up the rear of the carriage, to transfer the weight of the carriage and the barrel to the front wheels, permitting it to be rolled to the firing position at the front of the slide. Sometimes that process was bit uncontrolled, so the rope and bollard were added to control the rate of forward motion/descent.
Incidentally, that barrel is the one which was made in miniature by Jefenry, and featured on You Tube, firing at a range and off a canoe! Worth a search on You Tube. Just do a search on videos by Jefenry, or try these links.
The videos are from Jefenry, who is located in the USA.
So, today I battled 1.5 hours of post covid lockdown Melbourne traffic to take a closer look at the wooden slide and carriage of this 1866 Armstrong RML cannon which I am intending to model. There are 2 of them in the Hopetoun Gardens, Elsternwick. They are more complex than I had imagined.
The barrel is identical to the barrels which I had modelled on iron slides. The iron slides were a later improvement – modification.
It was a beautiful spring 20ºc day. I spent almost 3 hours photographing and measuring the wooden components. Some parts have been restored, and it was lucky that there are 2 examples to check and compare.
I was climbing over and under the cannon, and groundsman came over to check. Then a pair of grandparents came over with their 5 yo grand-daughter, and a further pleasant conversation followed.
Some examples of the photos…..
And an example of many pages of measurements and sketches…
There are 11 pages filled with details like this, representing my 3 hours.
And I still do not understand how the barrel elevation mechanism functioned. It could have been a wooden wedge called a quoin, but there appears to be a metallic disk set into the wooden bearer. Could there have been a screw mechanism which has since been removed/stolen/lost? Pictures on Google Images do not help. Does anyone know?
You might have seen the above photo in johnsmachines.com earlier this year. 2 Armstrong 80pr muzzle loading, rifled cannons are sitting on their ORIGINAL wooden slides, in Hopetoun Gardens, Elsternwick, Victoria. These were originally installed as garrison guns at Fort Gellibrand, Williamstown, Victoria and were never upgraded with the more modern, accurate iron and geared slides such as at Warrnambool, Port Fairy and Portland, and which were the inspiration for my 2020-21 modelling efforts.
I have decided that I will make another 1:10 scale model of the Armstrong 80pr RML, this time sitting on a wooden slide.
You might wonder why I am so obsessed with this particular cannon? Well, I wonder too. Perhaps it is the ready availability of an original in good condition, which I can visit, photograph and measure.
Anyway, I have made a start on this next model.
Cutting off 275mm of 76mm diameter bar. I bought this as mild steel, but it has remained so shiny in my damp workshop that I wonder if it is stainless.
The next step was to centre the 10kg rod in a 4 jaw chuck, install a 3 jaw steady, and drill the 16mm bore. Sorry, no photos, forgot. I had made a long series 16 mm drill bit by turning a shoulder on the shank of a good 16mm bit, and boring an accurate hole in the end of some 5/8″ (15.875mm) drill rod, and silver soldering them together. Then honing the bore to an accurate 16mm diameter, along its 275mm length. It worked well. So well, that I can insert a 16mm “projectile” in the bore, and watch it slowly drop through.
Then, continuing to hold the blank rod with its 16mm bore in the 4 jaw, and using the tailstock to hold the other end I manually turned the exterior of the barrel.
Why not CNC? Well, my CNC lathe is a bit light for turning a 10kg blank, and manual turning is still quite a pleasurable way to spend a couple of hours. The taper of the “chase” was done using the top slide set at 2.5º.
Turning the rounded chamfers. I could have CNC’d them, as I did for the original models, but in this instance I used a method which I had read about. That was to use a rounding over bit which is intended as a milling bit. But in this case it was held in the lathe tool post, and used as a form tool. It was very quick, and produced an excellent finish IMO.Next step was to make the cascabel. This started as a 20mm x 1.5mm high tensile bolt. The wide part was a steel disk which I threaded, and glued to the bolt with Loctite 220. I turned the bolt head down to 20mm. Then CNC’d the shape above. Still to come is the rope bolt hole, and flattening the sides. Tapping the barrel to accept the cascabel occupied a couple of hours.The new barrel has a better finish than my previous effort IMO. I used hydraulic oil mixed with kerosene as lubricant. 10kg stock originally, now weighs 4.2kg. Next step is the rifling.
My tandem trailer, was desperate for repairs and repainting. I bought the trailer about 23 years ago. It is 10′ x 5″, very solid construction, and a hydraulic tipper. I used it originally to transport animal manure to my olive trees. In recent years it gets more use on SWMBO’s building sites to remove builders rubbish.
The trailer as I bought it. I added the green “hungry sides” to increase the carrying capacity to about 5 cubic meters. The hydraulic pump runs off the Landcruiser battery. Here discharging rabbit manure to sit in piles for a few months before placing it around the olive trees.
Later, I increased the size of the ram to a multistage 5 ton unit, and changed the geometry to provide more lifting power. Also contracted a professional trailer maker to install Landcruiser hubs and wheels and heavier duty springs.
Landcruiser wheels. Looks more purposeful, and I can use the vehicle spare wheel as a trailer spare. On the farm I sometimes carried and tipped loads of 4-5 tons.
But the floor finally rusted through. So I installed a new 2mm thick steel floor over the top of the old rusted one. I should have removed the old rusted floor, but time was short, so I took the “lazy man’s” option.
Now, 23 years after the original trailer purchase, and about 18 years after the temporary floor fix, the floor needed to be replaced again. This time I did the job properly. I bought 2 sheets of checker-plate steel. Paid the supplier to fold the long edges. And started to remove both layers of the old floor.
The top layer of steel floor which I had welded in place came free after about 30 minutes of weld grinding. The original floor was attached by at least 100-200 welds, many in relatively inaccessible positions. After about 6 hours of exhausting work I removed about half of the badly rusted, excessively welded original floor. Another days work to remove the remainder. Then a lot of smoothing grinding, replaced one cross beam, treated rust, primed and painted the frame. Then attached the new checker plate. Then painted the entire trailer. The yellow seen is bright yellow before I added the red to give the hue an orange tint. Some of the bends could only be made as the job progressed. This setup worked fairly well.The folded up side lip should prevent water collecting along the corners, and slow down rusting in that rust prone location.2 sheets of 2mm checker-plate, 2440mm x 1220mm. I had a 50mm lip folded along the long side of each sheet, cut one sheet into 3 pieces, tacked the pieces together. I asked my expert welder friend Tony to complete the welded joins. Here applying primer to the underside.
Then attached the new floor to the trailer frame with galvanised hex head screws. You might wonder why I did not weld it in place? Well, removing the previous floor which had been welded in position was job which I never want to repeat. Plus, whether the new floor is galvanised or painted, welding destroys the zinc or paint, including in areas which cannot be touched up. The technique which I used allowed all surfaces to be thoroughly painted. So I removed the newly joined floor, and primed and top coated all surfaces, including the frame underneath.
Then re-attached the new painted floor permanently to the frame with the gal screws, and cut off the protruding points. I decided to not weld the floor to the frame, because that would destroy the rust inhibiting paint. I used silicone roof and spout sealant in the screw holes, and between the trailer sides and the new floor side lips. Then applied more silicone sealant into any cracks between the side lips and trailer sides.
Oh, I forgot. The cross members were U sections with the opening at the top. No wonder they rusted. Any accumulated water could not escape. A really dumb design decision by the maker. So I drilled drain holes in every cross member, removed the rust with a needle gun, and painted the insides of the U sections. I will finish the painting when the steel repairs have been completed.
More painting required. The frame the hydraulic reservoir and pump, and trailer wheels yet to be prepared and top coated.Quite a few hours of prep work, and 2 coats of paint to come. That is the 4 stage ram which I installed about 10 years ago. The new ram required a larger hydraulic oil reservoir, hence the extensions to the tank (bottom right). The end of this project is in sight!
Judging by the coats of existing paint, and alterations to the trailer construction, I reckon that this is the 4th major change to this trailer’s construction. It has done a lot of work. And lots more to come.
10 November 2021.
A bit more paint painting required in hidden areas, wheels, but this will be the final appearance. I am sure that the colour will not be to everyone’s taste, but I really like it. The spare wheel attaches to the post.A new switch for the hydraulic tipper, and the lights still work. Ready for another decade or two.
I have a 35 year old JCB back hoe, a left over from when I grew olive trees and made olive oil. These days it is used only as a yard crane, and other small jobs on a 5 acre property. But since I am between model engine and cannon projects I decided to expend some TLC on the rather neglected JCB.
One feature which always made me grimace was the broken slew lock plate.
The slew lock plate supports the excavator boom and jib when the backhoe is driven between jobs. It takes the weight of the rear end, taking weight off the hydraulics. Unfortunately the old plate has been broken and re-welded so many times that it is IMO beyond repair.
A new plate is $AUD 1300 + GST I could not find a machine for wrecking, and was told that wrecked JCB 3CX’s are almost unknown, most owners, mostly farmers, keep them going for ever.
So I measured up the plate, drew it up on CAD, and had it laser cut from 20mm plate.
The laser cut bits. 20mm plate and 25mm plate hinges. Cost? $AUD 180 including steel supply.
Deep V fillets were ground, and MIG welded with the 25mm hinge pin in position during the welding to keep the hinge pins aligned after the central portion of the pin is cut out.
Fitted to the excavator boom. I decided to not use the thin metal sloped flanges present on the original part, which I presume are to facilitate engaging the plate to the king post pin seen in the photo. I will engage the plate manually, by removing the securing pin (left) through the back hoe rear window.
Feb 2023 postscript. The slew lock plate has been in use since installation, and it is showing no signs of distortion despite me activating the hydraulics on several occasions, having forgotten to release the plate. I do need to exit the cabin to release the plate, which is a bit of a nuisance. I am thinking about adding a spring release mechanism so the plate pops up when the boom weight is taken off the plate.
I have had requests for copies of my plans for the plate. I am prepared to send them but with the understanding that I am not a qualified engineer, and I make NO representations about the suitability or safety of the design.
My JCB is a 1986 model, 35 years old. I have owned it for 10-12 years, using it for manure handling, as a yard crane, tree transplanting, and twice to lift a 50,000 litre water tank onto a tray truck. (in combination with a front end loader). Despite its age and hours of work (about 7200), it has been very reliable.
When I first bought it I engaged Enzed P/L to inspect and change any suspect hydraulic hoses, because many of them showed signs of cracking and delayering of the exteriors. And one had burst. I think that the onsite Enzed engineer remade and installed about 8-10 hoses.
Then recently, the hose to the rear bucket and boom controller burst. Well, actually it was the metal fitting which was crimped to the hose which split and allowed the hose to separate from the fitting, spilling quite a bit of hydraulic oil onto the ground. Enzed were on the job within a day, and an hour later the new large diameter hose and fittings were installed.
The hydraulic oil level was well down, and topped up with 20 litres.
I had been aware that one of the hydraulic cylinders had been leaking for many months, so not all of that 20 litre deficit was due to the burst hose. It had been leaking at the rate of one drop every 6 seconds for a long time, and increased to one drop per second recently.
I had recently purchased a kit of new seals for the leaking cylinder. After watching some YouTube videos, I decided to have a go at replacing the seals myself. No big deal really, except that I had not worked on a cylinder this large before.
This is the ram. The hydraulic hoses have been disconnected and covered with a clean rag to minimise any dirt entry. And the large heavy pins at each end have been removed.
The large gland nut was loosened before I removed the end pins. I had been warned that the nut would be extremely tight, and that it would be easier to loosen the nut while still attached to the JCB. The only spanner/wrench large enough was a Stillson wrench. I did not enjoy using it because it bit into the nut and marred the smooth surface. I had priced a new open ender spanner, but the cost was high so I used the Stillson. The Stillson was about a meter long, and the nut would not budge, despite using all of my strength and weight. Using a 1.5 meter pipe extension, the nut finally moved, and I loosened it until it stopped fighting. I caught much of the hydraulic oil which spilled out in a bucket, not to be reused of course.
I carried the ram into my workshop. At that moment I decided that any future resealing jobs on larger rams would be done professionally. It was quite heavy.
In the workshop I completed the removal of the large gland nut, discovered that the gland O ring and the main seal were in pieces.
Then removed the piston and its rod from the cylinder by pulling carefully.
The piston seals looked OK to my inexpert eye. But I had purchased a whole new kit of seals, including the piston seals and guides, so I replaced them all.
The new piston seals above, and the new gland seals inside and out, bottom. The gland and piston, and my hands were cleaned thoroughly, multiple times before and during the procedure. Most of them went on without much difficulty. The big rubber seal on the outside of the piston was the hardest. For that I used a heavy cable tie looped through the seal, to pull it into position. All good so far.
By the way, I had obtained a JCB service manual for my machine online, from Best Manuals, (USA) for $US19.99 and downloaded electronically. It had some very useful information. Including that replacement seals might be different from the originals. And they were. They looked different.
The seals went onto the piston fairly easily, with the assistance of a large cable tie, which was used to pull the large central rubber seal into its groove. The remainder of the piston seals were split, and positioned easily. The gland seals fitted easily, except for the large internal rubber seal which required considerable pushing and effort.
The gland was then pushed onto the piston rod, then the piston was screwed on, after cleaning the threads, treating them with Loctite 7471, and thread retainer 720. Then tightened with wrench and 1.5m extension.
My very untidy workshop, undoing the piston nut. The same setup for tightening. The manual specified 300 ft-lb, but my torque wrench does not measure such a large tension, so I just used all of my strength to tighten the nut, using the extension. The aluminium jaws are just supporting the rod. Most of the pressure is held by the foreground vice.
Then I attempted to insert the piston into the cylinder. But it would not go. So I pushed harder. Still no go. Tried wiggling. twisting, pushing harder. No Go. Bummer. 4pm on a Friday afternoon. Long holiday weekend imminent. Threw the parts into the boot and drove to Enzed. About 15″ away. Maybe there is a special tool or press to push the parts together?
They helped me immediately. I guess that my previous business a few days earlier and quick payment of their bill helped. They mounted the cylinder in a chain- pipe vice, and pushed and strained, but no better result than I had. The piston with its new seals just would not fit into the cylinder.
So, he compared the old and the new seals. The new ones were 0.3mm thicker than the old ones. And the diameters seemed larger. I had bought the seals from a JCB dealer, who had said that they were “after market”. Originals no longer made for such an old machine.
Discussion. Decision. Use the old piston seals. The new gland seals seemed fine, so keep them. The old piston seals appeared to be in good condition, and they were installed. And guess what? The piston slid into the cylinder with some pushing. The gland nut was tightened. (with a Stillson I noted).
The charge for 30 minutes of heavy, dirty, specialist time??? $AUD 23.00. I said, “that seems too cheap”. “That’s OK” he said. They will continue to get my business.
Today I re-installed the ram on the JCB.
Fired up the diesel. No leaks!
Operated the bucket control……no leaks, but no movement! Bummer! What now.
Hmm. Could I have put the hoses on back to front? No. They looked correct.
But hang on, the cylinder is facing the wrong way! The paint scuff marks which were on the outside are now facing inside!
I HAD INSTALLED THE RAM 180º ROTATED!
So, left the ram as was, switched the hoses, and tried again.
WOO HOO! No Leaks! (including when I tried different ram positions off camera).
I am still waiting to pour bronze to make a 1:10 scale Ottoman bombard. I have all the equipment and materials ready to go. But, held up by 1. needing some dry, wind free days, 2. ability to have a friend on hand to assist with the pour. I need 2 successive days for making each mould and doing the pour. Waiting, waiting. Meanwhile, SWMBO has had me breaking up a concrete drive, manually loading the broken up concrete, and transporting it to the recycler. It took 3 x 2 ton loads, so far, and still more to go.
Then in lockdown, we decided to fix a leaking balcony at home, and replace some rotting, ceiling boards under the leaks. At 71, I dislike working on ladders, above my head. Almost finished, thank goodness. And no more broken bones.
The leaks have been fixed. And the 8×2 beams are intact.Fortunately I was able to buy some boards to match the old ones. Doesn’t look much, but those patches took 4 sessions of about 4 hours each. Even more fortunately, SWMBO does not trust my painting skills, so she will do the painting after I have fitted the corner mouldings.
The lockdown restrictions eased a bit last weekend, permitting me to visit my workshop. I have been waiting for some suitable weather to burn some rubbish, and it was not too windy a couple of days ago, so this was the first task…
First weeks of spring, and with a fire permit obtained from the local authority, I had some fun with this. But even so, I had to put out some spot fires in the surrounding grass, which has already started to dry off. I am glad that I did not wait another week or two.
I have been considering my next modelling project. Nothing really is grabbing my attention. But I had to use the JCB backhoe to load the concrete onto the tipping trailer and I was aware that the JCB is looking really tired. Not surprising, considering that it is 36 years old, and has 7200 hours on the clock. I bought it third hand, more than a decade ago, and used it for general farm jobs, including manure handling, transplanting mature olive trees, as a yard crane, moving machinery, digging trenches. As a general farm machine it was incredibly useful. When the farm was sold, it was just about the only big machine which I retained, because even on 5 acres it is still used occasionally.
Transplanting a 10 year old olive tree. Even with many cut roots, they transplant very successfully.Handy for heavy lifting. My tractor at back was not getting any use so it is on permanent loan to a neighbour.4 way bucket at the front, can lift 1.5 tons. One of the rams has developed a leak, and will need resealing. The Perkins diesel starts easily and runs well. The back end is slightly loose, but not bad for its age. The tyres are down to about 15-20%. As you can see the paint work is ready for renewal, but there is no serious rust. The white roof is worst, so that is the first item for repainting. The rams are all good.I made this grab attachment for picking up vegetation trash, heavy beams etc.…like this heavy RSJ… I do not know what this plate is called. It secures the boom during travelling. It has been welded/repaired more than once, but as you can see the left hand yoke is broken and non functional. It is a casting. I have been searching for another one from a wrecked JCB, but no luck so far. So I am drawing up plans for fabricating one from 20mm steel plate. Some more laser cutting and mig welding required. (ps. it is called a “slew lock”). The interior of the cabin is not too bad. All of the controls function. The rapid steering knob was missing, so today I fitted this gear stick knob from my “might be useful one day” collection. It has a large spider embedded in the clear plastic.
So, until some new model engineering project takes control of my life, I will spend some time and TLC on the JCB.
I watch YouTube videos about megalithic sites around the world, including Peru, Cambodia, Russia, Bolivia, and especially, Egypt. I have been fascinated in the subject for over 50 years, since reading an article in National Geographic as a teenager, about the almost unbelievable stone work in Peru which was then ascribed to the Incas, (but that Inca origin theory now has many serious doubters).
One of those YT sites, “UnchartedX” , (to which I subscribe and support), frequently refers to the book “Lost Technologies of Ancient Egypt”, and recently did a 2 hour interview with the author, Christopher Dunn. The book was published in 2010, based on many visits to Egypt by the author. The interview led me to purchasing and reading the book. Although now 9 years (oops 11 years) since publication, his work is respected by Egyptologists, academics, and more free thinking enthusiasts such as YouTubers like Ben of UnchartedX, quite an accomplishment considering the degree of hostility between the opposing views.
Christopher Dunn is/was a toolmaker, engineer, and manager in the US aerospace industry, and expert user of CAD, CAM, lasers, metrology, and photogrammetry. He is also into ancient history. So when he visited Egypt he looked at the pyramids and other buildings and monuments, with the eyes of an engineer, and wondered how they “did it”. Over the course of many visits, he took increasingly sophisticated metrology devices and started to measure and take detailed photographs of monuments, temples, statues and quarries. He was staggered to discover the degree of precision to which many of these huge objects were made, in many cases of granite or basalt some of the hardest of all stones.
And he examined magnified views of the surfaces, to see the marks which remained, which might give clues about the tools which were used to create the objects, which in some cases are at least 4500 years old.
He carefully analyses the Egyptologists’ views that the tools were simple and primitive. Like copper chisels, and stone pounding rocks, and while not dismissing those views out of hand, leaves us with the impression that such results would be almost impossible in this CAD CAM era, and much less with copper tools and stone pounders. He does not mention aliens or pre-dynastic civilisations, but just states that the tools which made the pyramids, obelisks, huge precise statues, and stone boxes, those tools, unlike the copper chisels and stone pounders, have never been found.
He does point out evidence of large circular saws with a 38 feet diameter blade, hole saws up to 6″ diameter, and straight saws which have left tell tale marks in stone objects and quarries in many places.
In many cases, such as the huge, incredibly precise stone boxes in the Serapeum, and the absolutely identical pair of 40′ statues of Rameses 2, he just states “we have no idea how this was done”. The precision is not just in linear measurements, but in complex curves, and surface shapes and areas.
Dunn’s analysis is principally about the tools and engineering of Ancient Egypt. Equally fascinating, but not covered in this book, are the mathematics associated with the pyramids, but that is another story. Also, he does not believe that the Great Pyramid was designed as a tomb, but as a machine. But that also is the subject of another of his books, which I have not, as yet, read.
“Lost Technologies” is 360 pages, paper bound, illustrated with many black and white photos of variable quality, many excellent diagrams, and 16 pages of good colour plates.
The text is technical, but quite readable cover to cover. I found it difficult to put down. If you enjoyed Simon Winchester’s “Exactly” you will probably like this one.
This is not an in-depth examination of the question. It is rather my experience with a particular 3D printer. But I believe that my experience has been experienced by many other 3D printer owners, so I have decided to make this record.
The printer which I purchased was a Creality CR 10s. I bought it in January 2020. I had been considering such a purchase for a year or more, and finally took the plunge when faced by making components for the model Armstrong cannon which featured in this blog over the past 18 months, I realised that I would have to metal cast quite a few complex parts. And the “lost PLA” method seemed like the best option to cast those parts.
So I accumulated the equipment for printing the PLA, making the molds from jeweller’s investment medium, a potter’s oven for burning out the PLA and baking the moulds, a furnace for melting the aluminium and bronze, and assorted other necessary paraphernalia.
Choosing the 3D printer was difficult, coming from a knowledge base of close to zero. I asked members of my model engineering society which printers they chose, and why. I watched numerous YouTube videos, and read reviews. As usual, I discovered that the more information you absorb, the more confusing it all becomes. I have the same feelings when researching which car or camera to buy. Eventually, I decided to buy a lowish cost printer, with the idea that I would eventually replace it with a better unit for long term use.
For this first 3D printer I wanted a well known brand with a good reputation, a build volume which would allow me to print the biggest component of the model cannon (the barrel, which is 300mm long x 65mm x 100mm).
I was still mulling this choice when Amazon advertised a special deal for the CR10s, and I made a snap decision to take the plunge. Would I make the same choice today? Quite possibly (actually, no. see below). Although technology has advanced. I am now considering whether to add an Elegoo Saturn resin 3D printer to my ever growing list of machines.
So this is what I bought. It is an open frame 3D printer, with a separate box for the motherboard and controls, and a side mounted spool. Single extruder. Advertised as an auto self levelling base (but it is not. It is manual, time consuming and fiddly). Filament end detection (hence the “s” after the 10), which works well. The build volume is 300x300x400(h), which is at the high end of low cost 3D printers, and bigger than any of the low/medium cost resin printers. I used close to the full extents of the volume on several occasions.
Creality CR10s. Here printing in PLA, a gear which will be used to test the dimensions for the cannon barrel elevation gears. This was one of the first items which I printed. I was satisfied with the print quality. The arms which triangulate the vertical tracks on the printer were the first modification of the printer which I made. My decision to add the triangulation arms was based on my gut feeling that they would improve the printer. They cost $AUD65. Creality now includes them as standard equipment, which justifies my decision IMO. The cables between the stepper motors and the control box are messy and a nuisance and I watch them every time I do a print. I would NOT buy this printer again, mainly because of the cable arrangement.
Actually, the very first modification was the slicer software. The printer came with a free version of “Cura”, but I accepted some expert advice to use “Simplify 3D”, which I purchased ($AUD 175) and used exclusively until recently. More about that later.
The instructions for using the printer were in an illustrated 10 page booklet, and a pdf file. As instructions for assembling the printer, they were just OK (do manufacturers EVER test their instruction booklets on novices??). As instructions for fault diagnosis they are hopelessly inadequate. In my previous post I showed a paper back book which would have been immensely useful when I started this 3D printing journey, and HAS been immensely useful after almost 2 years of wallowing about in ignorance. (“3D Printing Failures” by Sean Aranda).
By trial and error (mostly error), I printed the parts for my model cannon, and also came to grips with the casting processes.
BUT. When I started printing components for my next project I experienced failures and frustrations which I could not overcome. The Ottoman bombard has only 2 components, the breech and the barrel, which I intend to cast in bronze, using the lost PLA technique. These will be the biggest castings, and biggest 3D prints which I have attempted. Not surprisingly, I had problems with the 3D prints. Some of my attempts at fixing the problems caused further problems. After reading Sean Aranda’s book, discovered that my problems had ALL been described, catalogued, and fixes known.
The problems were:
1. Poor plate adhesion causing models to break free during printing.
2. Poor adhesion between layers causing gaps and structural failures.
3. XY shifting between layers
3. Gaps between filaments which would cause casting holes.
4. Excessive stringing.
5. Lumps on surfaces.
And this was typical of the failures….
The barrel on the left shows layer shifting on the pins. The failures on the right show stringing, surface lumps, and adhesion failures between layers and within layers. A complete barrel print takes over 4 days, so there is a lot of printing time in that bin.
Then I decided on some upgrades….
An enclosure to prevents drafts, and keep the printing environment warm during cold nights. $AUD155. A temperature and humidity logger kept a record of overnight temperatures. The heated printer bed provided the heat. I noted that temperatures remained between 22 and 26ºc inside the enclosure.
An all-metal fully geared extruder. $AUD25
A filament dehydrator, and warmer. “Sunlu” brand. $AUD60. Old filament can be reconditioned by warming at 50ºc for 4-8 hours. The same machine can hold the filament during printing to keep it warm and dry.
Around this time I experienced a serious filament leak and blockage which bent the hot end enclosure, broke the wire to the thermostat, and broke some insulating material. The leak was caused by a loose extruder nozzle, and an imperfectly seated Bowden tube. It was probably repairable, but when I saw that the cost of a replacement unit, including the wiring loom, hot end, 2 fans, silicon boot, etc was only $AUD35. So I bought one, had it installed easily in a few minutes. It came very well packaged, and quickly.
Also about this time I read Sean Aranda’s book. It has been a game changer.
Aranda uses “Cura”, and although his fixes can been used by any other slicer, one of my problems was holes between walls and internal surfaces. He says that this is a problem which is worse with “Simplify 3D” than with “Cura”, and he also thinks that “Cura is a better program overall, mainly due to the quality and number of online updates. The fact that “Cura” is free is an added bonus.
4. Sean Aranda’s book. “3D Printing Failures”
5. Changed slicer to “Cura”. Although it is called “Ultimater Cura” it works on most if not all 3D filament printers.
6. Changed the stick-on printing surface to a new 3M cover. This was after I read the product information which stated that these surfaces last for only 10 prints! I am quite sure that mine lasted for at least 50 prints before becoming unusable. Now I print on different areas of the surface, and keep a record of the number of prints at each location. Since then I have bought a magnetic cover which I will use when the current 3M cover starts to fail. (p.s. I have now installed the magnetic base, and so far, it has been wonderful!). No break aways despite not using brims or platforms, and easy to remove prints
After all of those changes my prints have been excellent. No break aways, no X-Y layer shifts, good adhesion between layers, better surfaces, and no holes/gaps between filaments. The only problem is that I am not sure exactly which changes were effective and which ones were not. Probably they have all helped to a degree.
Postscript. I have been considering buying an Elegoo Saturn resin printer, or maybe even substituting the Saturn for my Creality CR-10s. From the reviews the Saturn produces much smoother surfaces, and more precise dimensions. And the prints are much faster. My 3 and 4 day barrel prints could be printed 5-10 times faster. The known down side is the is the cost of the machine (on special at Amazon at present for $AUD639), the smell, the need to avoid skin contact with the uncured resin, the desirability of a print washer/UV curer, and the need for extra space. The other major consideration for me is the smaller maximum print size. 200x192x125mm. The bombard parts would need to printed in halves and glued together in order to make the molds. So, while the CR 10s is working well, I will hold off buying the resin printer. There is some advantage in waiting because 3D printing is a constantly evolving and improving technology.
The most recent print. The breech of the Ottoman bombard, in bronze coloured PLA. Almost a perfect print. Sliced with Cura. I did not specify any supports, despite some horizontal overhanging surfaces, and that resulted in some loose threads on one surface (RHS), which should clean up reasonably. After that cleanup I will probably do some build up of the surface in wax. The print is 240mm long, 107mm diameter, and took 50 hours. I will be satisfied if the bronze casting looks as good as the print. A pity that the print will disappear during PLA burnout.And this one is a tool to try different clearance settings between close fitting parts. 0.5mm down to 0.15mm. Downloaded from “Makers Muse” website. Printed all components together. After minimal efforts to free up the parts, all clearances functioned, so if I was to print some gears, or other working model, I would allow only 0.15mm clearance at the design stage. I am not bothered by the substandard finish. I had set the extrusion width ratio at 0.9, and allowed no overlap for the walls and infill, so some infill gaps were present.
So, were the upgraded components worth it? A resounding yes, as far as I am concerned. Still pondering the Elegoo Saturn
P.S. a month or 2 later. Since I wrote the original article I have taken delivery of, and installed some 1 meter cable extensions, which were made for this machine. Obviously I am not the only Cr10s owner to have decided that the cables are a bit too short. The 6 or 7 cables were fitted with connectors and installed quickly and easily. The printer functions perfectly, and I can now place the control box a comfortable distance from the printer enclosure without worrying whether the too short cables will cause a print failure. Actually, the one meter extensions are a bit too long, and need to be carefully positioned to avoid snagging. Half a meter extensions would have been ideal. And the cost? $AUD35 with free postage. Considering the labour involved in making and packaging these items, the price was cheap.
I guess that title should read “2 Person Tongs” but I doubt that SWMBO will be volunteering.
I am still planning to pour a model bronze Ottoman bombard.
Wooden version. 520mm long, 107 diameter. I visited the 5.2 meter original near Portsmouth UK after I made this model, and I have refined the design of the new model.
The plastic model has been 3D printed, the flasks for the investment powder mould are ready, and I have the potter’s oven ready to dry, burnout, bake, and heat the moulds.
I have borrowed a melting furnace from Stuart Tankard, which is large enough to fit the crucible. The crucible has 14kg capacity. The crucible itself weighs 4kg. Unloading the furnace from my Toyota Landcruiser cost me a couple of broken ribs, which set back the project a few weeks.
Then I wondered about tongs to insert the crucible into the furnace, and, more importantly, how to lift the crucible full of molten bronze out of the furnace and pour the bronze into the moulds. The weight to lift and pour I estimate to be: bronze 10kg, crucible 4kg, plus tongs say 4kg = 18kg. The crucible with its bronze load will be at approx. 1100ºc / 2000ºf so some distance will be required for the gloved hands from the red-hot load.
3kg graphite crucible with tongs on the left, then ~5kg, and 2 x ~6kg. My new 14kg crucible at rear.
I have several pairs of tongs for smaller crucibles, but nothing approaching a 14kg crucible. So I asked Stuart T for his thoughts on the matter. He recalled seeing a video by an MSMEE member and suggested that I check it out.
John M’s tongs looked like they had been designed by an engineer, which was actually the case. I contacted him (by email because Melbourne is in Covid lockdown), and he generously offered to send photos, a video and a drawing.
I copied his design, with a few modifications based on the materials which I had on hand, and also to enable a 2 man lift and pour. In retrospect, I could have fabricated a one man pouring apparatus, using a swivel on a frame, but to be honest I would prefer someone else present for safety reasons.
8″/204mm ID pipe. I need to reduce the ID to 185mm To reduce the diameter from 204 to 185mm diameter I cut out 19 x 3.2 = 60mm plus a bit extra, then rolled the new diameter to 185mm ID. (shop made rolling machine)Yep, it fits the crucible.
The remainder of the tongs construction was basic cutting, welding, and drilling.
I cut more of the tongs away to reduce the opening diameter, to still fit Stuart’s furnace. The overshot bent handle closure requires a positive action to open the tongs- a safety feature. With the second man handle slotted in placeTesting the crucible and tongs in Staurt’s furnace. Cold.The open position
I used to be a half reasonable amateur welder, but lack of ongoing practice lately, and dodgy eyesight is my excuse for the lumpy welds and essential use of an angle grinder.
Next steps…. I need some dry, non windy weather, and availability of assistance for the pour. I will make the first mould, of the breech since it is shorter than the barrel, dry it, burn out the PLA, and bake it at 750ºc. That will take most of a day. While the baking is in progress (about 4 hours), I will start the melting of the bronze ingot. Stuart says that I will require 2 full 20kg cylinders of propane.
Then the pour. Then after some cooling with fingers crossed. Camera running…..
The 6th Victorian Covid lockdown was the shortest, but seemed to hit me the hardest. It was unexpectedly relaxed after only 5 days in regional Victoria, where I live. With escalating numbers in Melbourne, and Sydney, and NSW reacting by putting its collective heads in the sand we expected the be in lockdown for weeks or months, and frankly it was quite depressing. For the first 3-4 days I did a bit of garden tidying (with a chainsaw, much to SWMBO’s horror), and time on YouTube, Ebay, Banggood and Amazon. A fair bit of impulse buying, as follows.
Paragraph deleted. My political and religious views have predictably caused offense to some of my readers. While I do not resile from any of those views I accept that others have different views, and me having a rant is unlikely to be at all persuasive. So I have removed the paragraph. For those who agree with my views, my apology. Any further conversation about Trump, Liberal and labor politics in Oz, and religion, will have to be in private. (I still consider Trump to be a lying, ignorant, con man, and a disaster for USA and western democracies.)
So, having offended and lost 3/4 of my readers I will get back to my little buying spree…..
Firstly, a book.
I read some good reviews about this book, and since I have had considerable frustration with my 3D printing of late, I decided to buy it. 3D PRINTING FAILURES by SEAN ARANDA.
Paper back, 298 pages, large format, large print font size, 2020 edition. Under $AUD30 including postage from Amazon.Australia.
And it looks excellent. Clearly laid out and written, lots of pictures and diagrams, and the author even gives his email address and offers expert help if there should be a problem not covered in the book.
Some of the pictures admittedly are not great quality, but the author has a service which astounded me. If proof of purchase is emailed to him he will send high definition colour photographs for download. He sent me all of the photographs within 24 hours of my request. AND, a pdf version of the entire book. AND, a promise to send me free of charge a PDF version of the 2022 edition which will be published near the end of this year!
I have cherry picked some of the chapters and I am VERY impressed. They are VERY helpful. Some random pages follow….
This book should be included with every 3D filament printer purchased. Note that it does not cover liquid 3D printers.
In my previous post I showed a photograph of the enclosure which I cobbled together from cartons and a blanket to try and avoid printing problems arising from overnight temperature drops, and draughts. I intended to make an enclosure from MDF and perspex, but while browsing Ebay came across this one.
As you can see it was not a trivial cost. But when I factored in the difficulty in obtaining the materials during the lockdown, and the fact that the commercial one claimed some fire resistance, I bought it.
It came today, and with some levering of the cover on the frame, it assembled quite neatly, tightly, and well. Here it is with my printer.
As you can see the electronic control box is outside the enclosure. There is a flap on top for those who prefer the filament reel on top.
The front and top zip open. And there is some spare room for bits and pieces. It does look slightly neater than the previously used cardboard boxes. The printer is fully enclosed, even with a build in floor. The price seems to have risen a bit since I paid for this one. Time will tell if the print quality improves. I am predicting that the print quality will improve. After reading the chapter on fire safety and 3D printing in the book above I will feel more comfortable about leaving the printer unattended with this “Fire proof” enclosure. I suggest interpret that as “fire resistant”. I will be watching temperatures closely for the first few runs.
Still on the subject of retail therapy, a couple more purchases….
This is a woodworker’s gauge from Banggood. I bought it after watching a YouTube video about its uses. Nicely made, and reasonably accurate by wood working standards. I will do a separate post about it when I have more fully explored its applications. (it is for making perfect grooves and lap joints on a table saw).
And finally, this one was a splurge, impulse buy. But something that I had wished I had on quite a few occasions when making models.
As you can see it is a pin gauge set. It is Imperial because it was a fraction of the cost of a metric set. 190 pieces of ground and laser labelled cylinders, up to 1/4″. They seem to be as accurate as my Mitutoyo micrometer can assess. It does mean that I will be committed to a moment of calculation to metric when in use. Cost? About 50 cents per piece, including the case and postage.
Fortunately for my credit card, the lockdown ended 2 days ago. I have spent a couple of short sessions in the workshop, tidying up and doing some machine repairs and maintenance. Nothing really to show. But it is nice to be back.
It has been cold here during the current lockdown. And I mean temperatures. Not by American midwest standards by any means, but since we are confined to our homes except for limited predefined purposes, some days and nights are chilly. Down to 5-8ºc here.
I have been spending a lot of lockdown time doing 3D prints. And really struggling to get decent results.
Some of my GSMEE colleagues have been urging me to make an enclosure for my 3D printer. To be honest, Stuart T had urged me originally to buy a printer with an enclosure, but I pressed ahead and purchased an open structure model because I wanted the extra print size it offered. The Creality CR10s can print up to 300x300x400mm which I have fully used for my Ottoman bombard prints.
But in recent weeks, with the onset of the cold weather, I have noticed a distinct deterioration in print quality, particularly with poor layer adhesion when printing overnight, when the house heating is turned down or off.
So I decided to make an enclosure!
But, I did not have the materials on hand, and visiting hardware stores is verbotten with lockdown rules.
So, don’t laugh. This is what I cobbled together……
A couple of cardboard cartons, an artist’s A0 paper case (SWMBO hasn’t noticed it missing yet), and a blanket.
The heated printer bed is the heat source, at 50ºc. And I was surprised at the temperatures reached inside the rickety construction.
The steep temperature rise on the left is inside the enclosure after printing started. As you can see, the temperature rose from about 18ºc (room temp), fairly quickly to over 30ºc. After midnight, when the house heating was turned off there was a slow drop to 25ºc, and then a further drop to 18ºc when the printing finished and the bed self turned off.
The temperatures were measured with this gadget. A temperature/humidity logger.
Inkbird Temperature/humidity logger.
And the printing result??
The printer inside its enclosure, on the dining table.
This is the best quality print which I have had since the onset of winter weather. It is solid, water tight, and a reasonable finish. 0.2mm layer height. It is a molten metal pouring funnel, so I was not trying to get a super smooth finish, just an intact water tight object.
As soon as I can get access to Bunnings, I will make a more purposeful enclosure. Meanwhile, the cartons and blankets can remain in use.
I have given some thought to how to manage the bronze pour for the barrel of the Ottoman bombard. It will be at the size limit of my potter’s oven for the PLA burnout.
The red 3D printed PLA is the barrel. The breech, although significantly shorter, weighs almost exactly the same, but being shorter, should be less problematic. The wall thickness of the breech is greater than the barrel.
I had thought that the steel cylinder would be adequately long to cast the barrel, but it is about 50mm too short when I take into account the bronze feeder reservoir which will be required. So I will add a 50mm length, probably by arc welding another bit of tube to one end. It wont matter if it is not a perfect join. I will make it waterproof with duct tape. The tape will burn off during the investment melting/burnout.
I will cast the barrel with the threaded end downmost. The molten bronze feeder reservoir will be 60mm deep which I hope will provide adequate pressure and extra molten bronze if required during cooling contraction.
I decided that the usual rubber pouring funnel (pictured above at the bottom of the steel cylinder) would not have an adequately large bronze opening or reservoir depth, so have 3D printed one in PLA. The PLA will disappear during burnout, but will leave its shape in the investment medium and become the funnel and reservoir.
I wont be using the rubber cap/funnel mold. I hope that the 3D printed one works. Despite appearances the thin flat base is watertight. As shown here the funnel is positioned as it will be when the investment medium is poured. The cone seen is not a funnel. It is a distributor for the molten bronze. When the bronze is poured the cone will be point up.
Hard to get your head around that one? It certainly was for me when designing it.
You (and I) need to remember that any space around the PLA will become investment medium. The PLA will disappear and become a void which will be filled with bronze.
This screen shot of the 3D diagram might help. This is the pouring reservoir in the pouring position. The wide disk at top is to position the print on the steel flask. The skinny cylinders are vents to release air during the bronze pour. The stepped cylinder in the middle sits on the inside lip of the barrel. The inverted cone will be solid investment to direct the bronze into the barrel void. Confused? Maybe this will help. This is the position the PLA parts will sit inside the steel cylinder during the pour of the investment medium and later during the PLA melt/burnout.During the bronze pour the PLA components will be voids, which the bronze will fill. (except for the widest disk at the top which will disappear.)
The 3D print took over 8 hours. 0.2mm layers, 210ºc extruder temperature, 3000mm/min. I will need to do a similar 3D print for the breech. If either or both pours fail the whole process will need to be repeated.
Still in lockdown. Cannot visit my workshop due to the 5km travel limit. So 3D designing and printing at home is fairly good use of my time.
A few more small jobs out of the way, and some underway.
I showed you the “large” Kant Twist clamps recently.
Now I have finished the small ones. Same pattern, just reduced by 1/3. And a different handle.
Brass pins again. Machine cut knurl was simple with a CNC rotary table. No grooves machined into the jaws. They can be done later if required.Lathe chuck spiders are not new. I have made them from steel in the past, but I never seem to have the correct thickness. Fellow GSMEE member John Bernoth brought 3D printed versions to the last meeting, and it seemed like a great idea, so I have been printing up some too. The chuck has 20mm deep jaws, so I have printed 10, 5, 2.5 and 1.5mm thick examples. I discovered that levelling the printer bed is absolutely critical to getting consistent thicknesses. Best so far is the one at bottom which is within 0.02mm. The top one was an early one, and is only within 0.1mm, so will be redone. Notice the honeycomb infill. It has 10 surface layers top, bottom and edges, plus the infill. PLA. Quite strong, but very light. Seems a good application of 3D printing technology.
And back to the bombard. (The rib pain is easing). A 14kg crucible is on the way from UK. And I have the PLA models for the mold. I do hope that I do not need to reprint them.
The 350mm SS cylinder which will hold the PLA model and the investment medium, and eventually receive the bronze. The red barrel 315 x 107mm, and the black breech 240 x 107mm. There is almost the same weight of bronze in the barrel as the breech. The breech wall is much thicker, despite the smaller OD.
Now I am thinking about how to funnel the bronze into the mold, and where to place some air vents. Also have to work out how to drain the melted PLA during burnout cycle.
Will need to make some tongs for the new big crucible.
And for my non Australian readers, we in Victoria and NSW are in Covid lockdown again. So I have plenty of time for planning for the bronze pour.
I have been attempting to print a 1:10 scale barrel of the Ottoman bombard, in PLA, so I can make a cast in jeweller’s investment, and use that to pour a bronze version of the cannon.
I borrowed a big furnace to melt the bronze, and broke 2 ribs unloading it from my vehicle. That was about a month ago. They still ache a bit, but apart from careful positioning in bed, are steadily mending. I have to sleep on my back, which would normally make my snoring unbearable, but the CPAP machine is working quite well. SWMBO absolutely insists that it is in constant use.
And I have purchased a length of 5″ stainless steel pipe to make the mold.
I have featured the Ottoman bombard in previous posts, having made a wooden version some years ago. It is over 500mm long, and 107mm diameter. In 2 pieces with a big thread joining the pieces.
Just to remind you of the appearance of the bombard. This is the wooden version. 500+mm long, 60mm bore.
I can’t really justify a bronze version. It will weigh close to 20kg. But it is a challenge. And I think that it will look more authentic in unpainted bronze.
I printed the breech part a few months ago.
It is 240mm long, and with some post printing finishing will come up fairly well. The thread will be replaced by a redesigned thread. The original male thread on the Royal Armories bombard was tapered, so I have printed a tapered PLA version and will cut off the thread pictured above and glue on the new one before casting. I have tested the tapered thread in a test piece of printed barrel with female thread (which is not tapered) and it does go on much more easily than the parallel version, so that gun maker (Orban, the Hungarian or German) knew a thing or two.
3D PRINTING THE BARREL.
The barrel is 315mm long. My printer has a maximum print size of 300x300x400 mm so I was not anticipating any problems. I knew from the slicer program that it would take 2/3 of a 1kg reel of PLA, so I bought some new transparent PLA, thinking that it might melt/vapourise more completely in the burn out cycle of the production than the coloured PLA.
So I tried to print it. I have lost count of the number of unsuccessful attempts. Each time the print would start well, but at some point, sometimes after a whole day or 2 of printing, the print would come loose from the printer base and I would have clean up the mess of PLA spaghetti, and start again. I cleaned the printer base thoroughly. Scraped it. Wiped with acetone. Re-levelled it multiple times. But every time the print would break free.
I also noticed that I was getting a lot of stringing, and lumps of PLA would form on the printed surface, cool and harden, and sometimes the print nozzle would hit the hard lumps. That is when the print would loosen from the base and eventually break free.
I have been using a 3M printing cover over the aluminium printer base, quite successfully for over a year. Maybe the cover had worn out. I looked up the P.I. for the cover, and yes, it has a stated expected life of 10 uses! So that was likely the cause of the adherence problem because I must have used that cover at least 50 times!
I had no replacement 3M cover, so I reverted to the original cover supplied with the machine, which was boro-silicate glass. Initially it worked well, with good print adherence, but the hard lumps were still forming, and when the nozzle hit them, there was enough force to break the glass plate free.
What could be causing the hard lumps?
I watched multiple YouTube videos. Re-levelled the bed again. Checked every nut and bolt on the printer for tightness with no problem found. Checked the Z axis for level.
By this stage I was contemplating buying a new printer. Maybe one of those liquid + UV light jobs. But one of those big enough to make my barrel would cost thousands. So I got a quote from a professional printing service to print the barrel…. almost $AUD600. I would have done that, but the print is destroyed in the making of the cast, and it is possible that more than one attempt of bronze casting will be required. I was considering abandoning the entire project.
One last try at a print. I replaced the 3M cover with a new cover, and started a new print with a new reel of red PLA.
All seemed to be going well.
The print was adhering solidly to the new 3m cover. The hard lumps were still appearing, but the print head ploughed through them or knocked them off completely. The problem was, that after 3 days of printing, with 10% of the barrel still to go, the multiple jarrings were producing axis shifts. The appearance was pretty bad, but I figured that I could fix it with some extensive post printing hand finishing.
By this stage the print was almost 300mm high, and I could watch the laying of the PLA extrusion from the print head directly. In retrospect I should have used a mirror to do this at a much earlier stage.
What I saw explained the issue of the hard lumps appearing.
PLA was slowly oozing from around the base of the extruder nozzle. It was gradually building up into a pea size lump, and eventually falling off onto the print face!
So, I paused the print, picked off the accumulating lump, and watched some more. The same thing happened.
Why was the base of the nozzle leaking? Another pause. Checked the tightness of the nozzle. It was totally loose. About a full turn!
Tightened it up. Resumed printing.
The next layer did not adhere at all to the previous one, because tightening the nozzle had lifted it at least one mm.
The almost completely printed barrel. Lots of stringing. No hard lumps in this picture. This is in the dining room of my house. The room has been unused since the start of Covid. Quite handy and warm for printing.
I thought that I could start a new print of the final 10% of the barrel, and glue it to the part pictured, but when I examined it, the layers were poorly adherent, and falling apart. It went into the plastics bin. I expect that the loose nozzle caused multiple print faults in x, y, and z axes.
A record of printing failures.
So, I am now 32 hours into the next attempt, with 47% completed.
See the difference? No stringing. No lumps. Quite a reasonable surface. Fingers crossed.
Now that the Model Armstrong cannon is finished, I feel able to move onto some smaller projects which have been hanging around on my to-do list.
4-5 months ago I had these parts laser cut from 3mm and 4mm plate. GSMEE members have been making the Kant Twist clamps, and over the past 3 workshop sessions I have made a pair of the larger clamps.
There are side panels for 31 large and 32 small clamps. Most were taken by GSMEE members and some went to GSMEE Facebook readers interstate. I kept parts to make 2 large and 2 small clamps.
The machining of pins and jaws was very basic so I did not record those processes. The laser cuts holes were accurate enough to be reamed to size. I found 2 annoying mistakes, neither of which was fatal. There is an extra hole in the small side arm. And the position of the pivot hole in one of the arms is about 1mm out. Not sure how that mistake crept in. Neither of these mistakes will affect the functionality of the clamps.
Completed larger clamps. They open to about 90mm.I chose to use brass for the pins, screw thread, handles and jaws. I decided to peen the pins rather than use machine screws. I had never “peened” before, but after the first effort bent and snapped I modified my technique. The failure occurred when I used a 20 ton press to do the peening. So I drilled that pin out and next time I used a light hammer to do the peening, and that worked fine. The pins have substantial shoulders as you can see from photo above, and they were turned to be a sliding fit in the holes. Then the outer 2/3 of the holes was given a very slight taper ream. It was a 7º included angle. Then the light/medium hammer tapping to cause the pin to expand into the taper. Incidentally, when I removed the failed pin, I discovered just how secure the joint was. It was quite difficult to get it out. I had to file the protruding end completely away, then drill a substantial hole through it before it would budge with a pin punch. I used countersunk machine screws to hold the jaws, so I can make job specific jaws in future if required. The machine screws were ground to length so they lock together in the middle where they meet. That allows the jaws to rotate if necessary to use different faces.
The taper reamer used prior to peening
I would suggest one design change to the clamps, which I will apply to the small ones when I make them. I would add a small extension to the handle boss, say about 12mm, and knurl it. That would facilitate speedy changes to opening settings, before tightening with the handles.
Time and use will tell whether my choice of brass was sensible.
I know that these clamps can be purchased on Amazon and other sites, but this was a very satisfying project, and I have no regrets about deciding to invest the time to make them.
Small drill bits (up to 3.2mm diameter) are almost impossible to sharpen. Most of us just just buy new ones when our bits get dull. They are not expensive even in packs of 10.
But, sometimes we have parts which require sharp bits. (see recent post on installing model cannon sights). Even new bits are not necessarily correctly sharpened. I use Sutton drill bits which in small sizes cost ~$AUD18-20 for packs of 10 bits, but for crucial jobs I would like to touch up even those quality bits. The Sutton bits which I used for the cannon sights worked well, but the tense job made me very aware that in future I NEED to make sure that the bits are sharp.
So, I made a jig for sharpening small drill bits. The plans were published in Model Engineer 29 Dec 2000 and 26 Jan 2001.
It was a simple build. Took me 2 workshop sessions of about 2 hours each. I had the jig plate laser cut, very inexpensively from 2mm mild steel plate. Distributed to interested GSMEE members. The drill bit holder is an Asian copy of the English “Eclipse” pin chuck original. Also inexpensive. Came with 3 collets, to hold sizes up to 3.2 mm diameter. Cost $AUD10 inc postage. Note that the 1/4″ shaft actually measures 6.25mm diameter.
I used M2 and M3 metric fasteners in preference to the specified BA10 and BA8 fasteners.
The pin chuck should be through drilled in order to accomodate longer drill bits. The Asian pin chuck was not difficult to drill with a 3.5mm cobalt bit. It appeared to be case hardened only. And I used 2mm mild steel plate instead of the specified 16g brass plate for the jig. The wheel mounts were modified to cope with the different plate thickness.
M2 and M3 fasteners. 1cm grid.Magnification is required to position the bit at the correct angle in the pin chuck. (the 1.5mm bit shown is not exactly at the correct angle in the staged photo above).
The plans and instructions for use are in the articles in Model Engineer listed above.
p.s. GSMEE members who intend to use the laser cut plates. The drilling positions marked by the full thickness crosses can be successfully drilled to 1.6mm and 2.5mm by using sharp drill bits at high speeds- 3000rpm, slow feed rates, and cutting liquid. I used TapMagic.
And, it works! Here I am testing a 1.5mm bit which has been sharpened with the jig. Drilling through 4mm mild steel.
The sights were the final parts to be made for the model Armstrong RML.
There were reasons for delaying these items. They are tiny, easily dropped and lost, have tiny almost invisible details (to my eyes), and involve fine and very deep drilling into the barrel, on which many hours have previously been expended.
First I looked up every reference I could find about the full size originals. I could find no picture of the sights on the 80pr Armstrong, but I did find some diagrams of the sights on the Armstrong 64pr, on which the 80pr was based. Another problem was that there were rapid developments in sight technology, and I had to decide which period I would choose. The later periods (after 1880) had complexities which did not exist in 1860. In the end I just made decisions, knowing that they might not be exactly correct, but thinking that if further information surfaces I could make and install new sights.
This is the design I chose. The 64 pr had 3 pairs of sights, the 80 pr had only one pair, on the right hand side.
The next step was to drill some 2mm and 3mm holes into the barrel.
The drilling setup. The barrel was held firmly between brass strips. The breech end of the barrel might need a bit more finishing.
First I milled 3mm flats. The first milling bit, solid carbide, just snapped as it bit into the barrel from the side. A HSS bit was more long lived.
A complication was that the foresight was vertical, but the hindsight was sloped 2º inwards to adjust for slight lateral deviation of the projectile which results from the rifling.
Next, a 2mm hole was drilled right through the barrel, missing the bore, and exiting through the bronze bracket which supports the elevation quadrant gear. At 40mm deep that hole qualifies as deep drilling. Tension drilling.
I did not have a long series 2mm drill bit, so I silver soldered an extension, leaving 40mm of the 2mm bit exposed. No photos of the deep drilling. I had other things on which to concentrate. The drilling was actually uneventful.
Showing the drill sitting in the holeFabricating the sights involved silver soldering 0.5mm brass strip to 2mm stainless steel rod. This was the soldering setup. The the sights were shaped by belt sanding and filing.
And now for some sights of the sights on site.
I will polish the sights.Apart from dusting the base, and some final polishing, the model Armstrong cannon is now completed.
Most hobby modellers who use a CNC lathe, run the lathe with Mach3 software. Some have progressed to Mach4, but apparently 4 is not straight forward, and my expert advisor says that it is best to stick with Mach3 for the time being.
Mach3/4 requires instructions to control movements of the lathe carriage (X and Z movements), spindle on and off, spindle speed, coolant on and off etc, and those instructions are in the form of G codes.
G coding is not difficult to learn. There are excellent YouTube tutorial videos on the subject, Udemy courses, books, and so on.
The problem is that mistakes in G coding can be easily made, costly, and sometimes scary. The biggest problem is that G coding is time consuming.
Fortunately, software is available to make G coding automatic, fast, and reliable. This post is about the program which I use for G coding. It is called Ezilathe. It is available at no cost as a download from CNCZone. (see details of downloading later in this post).
Ezilathe was written by Stuart Tankard, who I met a decade or so ago at a meeting of GSMEE. Stuart gradually persuaded me to get into CNC, and frankly, the decision to do so has resulted in a quantum leap in the scope and standards of my model engineering efforts. Now I use a CNC lathe, CNC mill, CNC rotary table, CNC 3D printing.
But I digress. This post is about G coding for CNC lathe. Until Ezilathe came along, I was programming G codes manually, making mistakes, and consuming lots of time. And experiencing crashes. Exciting, damaging, and sometimes dangerous.
To CNC turn an object, the profile must first be drawn with a CAD program such as AutoCAD. There is a very basic CAD drawing facility in Ezilathe, but it is so basic that I prefer AutoCAD. In AutoCAD I then rotate and move the object as it would be held in the lathe chuck, and move the tailstock end of the profile to the X=0, Y=0 position. Only half of the original drawing is required, so I delete everything below the X 0 line. I delete or hide all lines which are not part of the profile. The profile can be saved as a polyline, or as separate lines, arcs, splines etc. It is named and saved as a dxf file.
Then Ezilathe is opened, and the dxf file is imported.
The stock diameter is entered. The z position of the tailstock end of the profile is entered (usually Z=0). Feeds and speeds are entered using the tables in Ezilathe or another source. I use an app named “FS Pro”. Also select which lathe tool is to be used (the lathe tools are all entered in advance) or select a “point tool” which has an infinitely sharp point, and no width. In the example shown in the pictures below the turning was achieved with one tool. If multiple tools are required on one job, each tool will have to been set in the tool editor. So far I have not used the tool editor, but I can vouch that it works well, having seen the superb results which have been achieved by Stuart.(see the photos below)
Then the polyline of the profile, OR, each line and arc etc is selected in the machining sequence. Important not to miss any small lines or arcs as unintended results can occur. That is why it is sensible to save the original drawing as a single polyline. (Stuart tells me that any gaps will be automatically filled by Ezilathe as straight lines.)
Then go to the simulator, and see how Ezilathe will manage the sequence of cuts. In the picture below, the cuts are the straight lines, and there are 2 finishing cuts along the profile.
If all looks well, generate the G code. I usually visually scan the G code, looking for obvious errors. Usually there are no errors. Save the G code. Then ready to use the G code to make the part.
AN air cut with no work stock or cutting tool is sensible for beginners.
This was a demonstration of Ezilathe to GSMEE members. Stuart Tankard watching carefully to correct any of my errors. The G code is on the right side of the drawing.This is the CNC turned finial, which was demonstrated to GSMEE members. Fortunately the turning all worked out well. I made this bookcase about 30 years ago. Can you see the finial? It was a very delayed addition.Now some examples of items made by Stuart using Mach3 and Ezilathe. All of the components in this valve were made by Stuart.And when he makes an item he finds it difficult to stop churning them out!pretty rough hey!Stuart made this cutter to make the seats on the valves. Some turning on the lathe using Ezilathe, and some mill work. And heat treatment. Not bad hey!
There is a lot more to Ezilathe. This has been a very brief introductory summary. Creating a lathe tool library, and entering startup strings for different lathe setups for example.
To download Ezilathe, you need to register at CNCZone. It is quite a good, useful site. In CNCZone go to downloads, Postfiles, Page 2. Select Ezilathe, and Ezilathe.pdf. The pdf is a comprehensive manual. Save them to a directory named C:\Ezilathe and unzip them. The program has been fine tuned, and updated. The latest version is 1.7.3. Then, on page 1 of Postfiles there is a small bug fix, Version 1.7.3.3. 1.7.3.3 is an executable which should be run after 1.7.3 is installed. If there are problems or questions Stuart can be contacted via CNCZone.
I have no hesitation in recommending this excellent program. It is just amazing that it is free.
Well, that heading is bit misleading. I had no pre-existing plans. I drew plans up myself, using the original cannon to measure, scale down and get my model dimensions.
In my posts over the past 18 months you have seen plenty of pictures of the original cannons, and the models.
I decided to model the particular cannon because I liked the shape, the degree of mechanical complexity with gear trains, riveting, etc, and because of the association of the town (Port Fairy) with my son in law. Also, because Port Fairy is within driving distance, if further dimensions and details should be required, which they were.
I thought that a model would look interesting and impressive. And it could be built in 3 distinct stages. Chassis-slide, carriage, and barrel.
So, in the order in which things happened……. (this info is all in older posts, so turn off now if the repetition is boring. I am writing this post for an overseas reader who wants to know how it was all done.)
I used a digital camera and iPhone to take photos of the entire cannon and its components. Close up, and from a distance showing the relations. The straight lateral, front and rear photos were particularly useful. In total, about 200 pictures. The photos were printed A4, and catalogued. As the model building progressed I realised that I had missed some components, and 2 further photo sessions were required. That was complicated by the Covid restrictions, but managed with some delay. The best photos were in overcast weather conditions, with and without flash.
I measured as many dimensions as possible, using a builder’s tape measure. The dimensions were recorded on hand drawn sketches in a note book, and a phone app (<My Measures Pro>. Very useful). On a later trip I used digital callipers for some small details. The barrel was measured using circumferences, and calculating diameters from those.
Using AutoCAD, I drew up a simple side profile plan. In that process I realised that many more measurements were required, and repeat visits were made. Actual components were later modelled using 3D CAD and saving as STL files. The STL’s were used to make 3d prints for casting, and in some cases just to see how the part would fit into the cannon assembly.
I searched the Internet for any references to the particular cannon. In that process I discovered that the particular cannon was unusual, and it appeared that all 26 examples from the Royal Gun Factory had been sent to colonial Victoria. Identical cannons were to be found in 2 other towns close to Port Fairy, and in 2-3 locations elsewhere in the state of Victoria. The design (of the 80pr original) was very close to a smaller capacity cannon (64pr) of which examples are still located in Hong Kong, Singapore, UK and probably elsewhere. It gradually dawned on me that the differences between the 64pr and 80pr related only to the construction method of the barrel, and not its appearance. Google, Google Images, Wikipedia all had information. I even discovered some images of simple plans with dimensions of the 64pr cannon, which corresponded very closely to the dimensions which I had obtained from the Port Fairy original.
As I posted progress of the model build on this blog, various readers offered further information, some of which was very useful. I have had some very satisfying subsequent correspondence with model cannon builders. In fact, the blog correspondence has led to some very useful experts who have been of immense help. One even supplied me with a copy of the original operating instructions for the Warrnambool 80pr cannons.
Searching for books on the subject of artillery in the 19th century has produced two which were published in 1877 and 1897. These are available free of charge as downloads, and bound reprints were purchased in addition. The cost of the bound books was very reasonable ($AUD20, and $AUD50). These have been thoroughly read, thumbed, dog eared, and used. So much so, that one of them is due for replacement.
Discussion with several experts has provided further great information, and resolved some of my questions. I had been mislead by some inaccurate restorations of the cannons at Warrnambool and Portland, and my suspicions about the restored details were confirmed in those discussions. The cannons at Port Fairy have had no restoration, which has resulted in severe rusting, but at least the remains are original and genuine.
Steps 1,2 and 3 occupied me on and off for about 5 days. 4,5,6 and 7 occurred progressively over the following 12-18 months during the model construction.
Regarding the accuracy of my scale models compared with the originals, I make the following observations.
As far as possible the linear dimensions are at a scale of 1:10. That was the scale of the first cannon I modelled, and I have stuck with that 1:10 for consistency, comparison between different cannon models, and simplicity of conversion. Of course that means that surface areas are 1:100, and volumes and weights are 1:1000. I have made some compromises to enable use of standard fasteners, shafts, and bevel gears, but have kept the compromises as small as possible consistent with the visual appearance.
Materials. The original cannon was constructed of wrought iron, cast iron, bronze/brass and wood. Steel was used only for the top surface of the slide. I used mild steel for the slide, the chassis, the carriage and the barrel. I used bronze or brass where the original had bronze. The wheel assemblies were cast iron on the original. I was restricted to cast aluminium and later cast bronze, but since these components were painted, the exact metal is not detectable, and probably irrelevant. The original wooden chassis/slide was made in the UK. The later iron chassis/slide was ,made in the UK but modified in Melbourne. That is the slide which I modelled. I imagine the original wood components to have been oak, but with no certainty. Scaling wood is difficult, due to the problems of scaling the figuring. I have some European oak offcuts, but decided to use Australian jarrah, because of its fine grain and attractive reddish colour.
Colours. I could find no reference anywhere regarding original colours. The experts had no hard information about colours and neither of the books mentioned colours. Some opinions were that black was most likely, and for cooler climates that seems reasonable. But in a hot Australian summer, black iron objects can be too hot to touch. I therefore suspect that white or at least a lighter colour would have been most likely used. But, you know what? SWMBO offered the most sensible advice. She said that if the model is to be on display it has to look attractive. She recommended painting the boring bits flat black (carriage sides, recoil tube, wheel assemblies), and leave the remaining metal uncoloured. Even the copper rivets, which would have been iron in the original. And to polish the bronze and brass components. So that is what I have done.
The base. A lot of thought went into this. The original ran on circular iron tracks which were set into concrete slabs. I rejected a circular track on the grounds that the model would have been too wide for convenient storage and display. I also rejected concrete or model concrete in favour of the eventual choice. That decision, (incidentally, not “set in concrete”…. might be changed at a later stage), was for a single piece of 12mm thick gloss black cast acrylic Lexan, sandwiched to a piece of thick plywood which is painted flat black. It looks good IMO, is hard wearing, and reflects the internal components so they can be seen. The first model Armstrong which I made was set on a wooden base with oil polished top and black painted sides. That also looks quite good. (IMO).
I might add to this list if further memories surface of the various processes used in the planning stages.
Just one picture for those readers who never read the text….
the Armstrong 80pr model cannon sitting on its Lexan/plywood base. The name plate has subsequently been moved to the back end to be less intrusive. Can you see the “Marshall’s Iron” lasered to the muzzle? If so your eyesight is very good. Sorry about the flash shadow. And that theatrical degree of barrel elevation would rarely have been used. Most shots were fired within 2º of horizontal.
I made them promise to not make me laugh or cough or do any heavy lifting. And it was a pleasure to attend another face to face GSMEE meeting after a few weeks of Zooming.
John Bernoth has made his Kant Twist clamps from the laser cut arms. He used countersunk screws to hold the pins, instead of peening the ends, so he could easily disassemble the tool if required, and because he had the screws already. Used aluminium jaws. These are the small clamp version.
And Swen Pettig brought along his Grasshopper beam engine for a progress assessment.
It is looking very interesting. Not finished, but is apparently running on compressed air. The flywheel is made from assembled machined pieces which are screwed and silver soldered and peened together. Double acting cylinder has 3″ stroke 1.5″ bore. I am really looking forward to seeing it running on steam.
Swen has also recently made this sphere making lathe attachment. The cutter is a 6mm diameter TC disk. He showed us an example of a job, which has a lovely finish and excellent shape, but a rather thick neck. Swen plans to make another cutting tool with a sharper point to make thinner necks on the spheres. Chatter has not been a problem with this tool.
I am not quite ready to show the Armstrong RML gun, because it is still waiting for me to get back into the workshop for some finishing touches, so I brought some goodies to show which I recently bought from Banggood.
A pair of hold downs for the mill or mill drill. These are really nicely made and finished. $aud25 each.A smallish square with an extra face, which should be useful for set ups on the mill. I had previously bought the smallest size, so adding to the set. Cost was around $aud15 from memory. Again, well made and seems accurate.
And this one is a woodworking tool, which I have wanted for some time, but the US version is about x4 the cost , and postage is an extra deal killer. The costs mentioned all included postage.
It is a marking gauge, 0-200mm, with 0.2mm divisions. About $aud20.Made in You Know Where, but the fact is, that this stuff from Banggood is really nice. Whatever we think of their government, the goods are usually excellent.
Today I picked up the laser cut metal plate which will become the small drill sharpening jig. For drills bits up to 3mm. You might ask why bother? Well, I can see the jig being used where I want a really sharp tiny drill, on a critical job. I would touch up the cutting edges on even a new bit.
The crosses at the drilling points are a bit of a nuisance. I had asked for a mark only. The full thickness crosses will have to be drilled very carefully to avoid breaking the drill bit. If they prove to be a big problem I will have to get the parts remade.
The drill bits to be resharpened will be held in a small collet chuck, purchased commercially for about $10, including 3 collets. The lasering cost about $5 each.
Several weeks ago one of my grandsons broke his wrist. In a discussion about the accident with SWMBO I mentioned that I had never experienced a bone fracture. (mistake #1).
Some days after that I collected a metal melting furnace from Stuart Tankard. A loan, so I could melt enough bronze to cast the Ottoman bombard. My own furnace has a capacity of 3kg of bronze, but I needed to melt about 10kg for each of the two parts of the cannon. Stuart’s furnace is gas fired and will take much larger crucibles than mine. He readily agreed to the loan of the furnace, but I noted that he hesitated when I rang to arrange the pickup. I discovered why when we loaded it.
It is bloody heavy!! The two of us could not lift it more than a few centimeters. It must weigh around 200kg.
So, we manoeuvred it onto a hydraulic lift trolley, and used that that to roll it to my Landcruiser, jacked it up, and slowly and progressively moved it into the back compartment of the cruiser. I assured Stuart that I would be OK unloading it. (error #2) I have an identical hydraulic lift trolley. And I was sure that I could carefully manoeuvre the furnace onto the trolley.
So, at my workshop I backed the cruiser to the concrete pad where the trolley was positioned, jacked up the trolley platform to the level of my cruiser and slowly pulled the furnace towards the trolley. But it would not budge.
The furnace has a handle for rolling it around. The handle slips into position quite neatly. So I climbed onto the cruiser floor, and started pulling and manoeuvring (error #3). Suddenly, the handle came free, and I was flying through the air tumbling backwards. Fortunately the furnace stayed where it sat.
But I hit the concrete pad.
Hard.
With my chest.
Initially I was winded. And my chest hurt like hell. And my head hurt. When I stood, I realised that I was conscious, bit giddy, and in PAIN from my chest. Oh shit. I knew that I had probably broken a rib(s). It hurt to breath. I took shallow breaths. No bleeding, but I was sure that there would be some impressive bruises.
As was alone, with no-one nearby, I rang my wife. By then I had regained my breath and I reassured her that I was not seriously hurt, and did not need an ambulance. But if I did not turn up at home that evening maybe she should come and find me. (sensible#)
As time passed, the pain did not seem too bad, so I had a cup of coffee, some Aspirin, finished unloading the furnace, and a couple of hours later drove home. I took some more aspirin, and started cooking dinner as usual. My wife said that I should see a doctor, but hey, I used to be a doctor, and I knew that nothing serious had happened. (error #3). Also it was a public holiday. My doctor would have either been on call, or arranged suitable cover. But I figured that it could wait until the next day.
After an uncomfortable, restless night, the next morning I felt sore, but not in severe pain, and it settled with some more aspirin. We were child minding that day, so seeing the doctor would have been very inconvenient. So I did the child minding with my wife, with no great problems. Then another restless night. I planned to see my GP the next day. Or at least to talk to him with a phone consultation.
Next morning, I sneezed. Hay fever. The chest pain was suddenly much worse. Aspirin hardly touched it. Some movements were very painful. I was terrified that I would sneeze again. Deep breaths were out of the question. I rang for an urgent appointment with my GP. It was made for late that afternoon. I knew that I needed an X-ray of my ribs, so I sent an email to my doctor. It is almost impossible to get to talk directly to a doctor without a prior appointment but I thought that an email from an ex-doctor might might get through. And it did. I had a phone call from him within minutes, and the X-ray was arranged. He also arranged an electronic prescription for a stronger pain killer, which my wife collected. It helped.
I had the X-ray, driven there by my wife, who by this stage was very concerned.
At the pre-arranged consultation the GP examined me. Clinically he agreed that at least one rib was fractured. However the X-ray report said that there was no fracture. He invited me to view the X-rays, and I was certain that I could see a fracture. I was no radiologist but I had seen a lot of X-rays in my medical career. A second radiologist opinion would be obtained. (the second opinion confirmed the fracture). My lungs were intact at that time.
I did not require hospital admission. I was given a prescription for more pain killers, instructions about keeping active, taking laxatives (to avoid the analgesic induced constipation), and to stay in touch for the 6 or so weeks that healing would require.
The next day the situation changed. Despite the strong pain killers, the pain progressively worsened. By evening, when SWMBO arrived home I was having frequent episodes of agony in the area of the fracture(s). I discovered the meaning of the phrase “pain bringing someone (me) to his knees”. It was worse than the root canal pain, the ski accident multiple ruptured ligaments and crushed bone ends pain, you get the picture. I was almost fainting with the pain. SWBMO wanted to get an ambulance. I did not want the delay. So she drove me to the hospital casualty. Every bump in the road provoked the agony.
At the hospital, I staggered into the casualty department while SWMBO parked the car. There was a queue at the triage assessment. I had put on a mask as per Covid regulations. I was doubled over with pain, and wondering if I would faint if a severe wave occurred. I was aware that I was groaning with the pain. Waiting people were staring. But the triage nurse was not looking. So I walked to the window and said “I am in severe pain”. She said “sit there”. I said “I cannot sit down”. She pointed to an adjacent room and said “wait in there”. So I did, while she continued getting details from the two people ahead of me in the queue. I was bothered by the attitude, but in no condition to argue. I guess that she was following protocol. I wonder what protocol would have required if I had collapsed.
Eventually, after an interminable wait (probably about 5 minutes) I was motioned to window, gave my details, and I was walked with assistance from 2 orderlies, into a cubicle. Things moved quickly then. An IV line was inserted, and I was given IV Morphine. A few seconds later the pain was almost gone. It was heaven.
A CT scan confirmed the fractures. And partial lung collapse. My liver was intact. There was no internal bleeding. Hospital admission was recommended, and SWMBO insisted that I accept, although after the Morphine I was tempted to go home. Anyway, I stayed overnight, with strong oral painkillers every 3 hours.
I was discharged home the next day with a supply of really strong painkillers, and arrangements for follow up. Since then, I have been slowly improving. I have a strange “clicking” sensation at the site of the fracture. Something is moving. Yesterday I visited the workshop, but not really up to anything interesting. Doing a lot of dozing.
According to WordPress Support I cannot insert a table of contents. But this list might be helpful to find an old post. Just do a search on one of more of the words in the title.
Armstrong 80pr RML cannon carriage sides.after some finishing and painting.
I started with virtually no knowledge about this subject, but I had to learn quickly in order to finish my 1:10 model Armstrong rifled muzzle loading 1866 cannon. I finished the job, not perfectly, but adequately, and this is what I have learned so far.
Copper rivets are annealed when purchased, but as soon as you start hammering them, they harden.
You need one hand to hold the work. If you use a hammer, and hold a snap, that uses 2 hands. So either use a third hand or use a pneumatic hammer with the snap attached. That leaves a hand free to hold the job. The pneumatic hammer size must be appropriate for the job. I purchased one from the country of Taiwan. It cost $AUD120. Seems to be excellent quality.
The compressor pressure is critical. The air setting on the hammer is critical. Experiment on waste material first!
Hold the fixed snap in a strong vise.
The snaps need to be accurately made for the rivet size. Try them on waste material before using them on the job.
Rivets of the same size but from different manufacturers will differ in finished appearance. Get your rivets from a single supplier in one batch. Order 10-20% more than you think that you will need. You will lose some, and muck up the insertion in some.
The surface of the snaps should be smooth, with rounded edges. A polished finish is best.
A complex job, with internal rivet ends, requires custom made snaps. Be prepared to make them. For the carriage parts I used 5 different shaped snaps. For copper rivets, mild steel snaps were quite adequate.
Some rivets will not insert well. Just remove them, and try again.
To remove a rivet, grind off one head. It might then push out with a steel pin. If necessary, drill through the shaft with a small drill (say 1-1.5mm for a 2mm rivet), then punch the remains out of the job.
The rivet length must be precise. The head which is formed by the snap was best if the shaft length was 2.5mm longer than the total thickness of the materials to be joined. There are tables to determine the lengths.
To shorten copper rivets, drill a hole in steel plate which is the exact thickness of the desired rivet length, the exact diameter of the rivet. With the rivet in the hole, snip the rivet to length with wire cutters, then belt sand it to length. Push the rivet out backwards.
With grateful thanks to Neil M for expert advice on this subject.
The lettering on the muzzle reads “Marshall’s Iron”. It refers to the steel bore of the barrel, which was supplied to the Royal Gun Factory by a specialist manufacturer, Marshall Iron. The rest of the barrel was made from wrought iron, as a coil, as described in a previous post.
Stuart operating the fibre laser, and Jamie who runs Stuart.
The barrel is 300mm long, too high for the laser machine to focus. So the setup used a low profile 3 jaw vice, hanging out from the edge of the machine, with the breech of the barrel down the front of the desk/bench.
Immediately after lasering, which took about 20 seconds, (and about 45 minutes to set up the machine/supports). The circle represents the junction between the steel bore and the outer iron coil. The vertical line was used for sighting.
The lines and lettering looked a lot sharper after a quick rub with emery paper. Those letters are less than 1mm high. A very magnified, not well focussed photo.
The cannon is now mounted on a shiny acrylic/wood base. It reflects the underneath details. And has handles.
Thanks once again to Stuart Tankard, for using his fibre laser machine to accomplish the engraving. Stuart told me that he has done more jobs for me than he has done for himself. I call it “getting experience”.
And, WordPress has now improved its program to the point that captions cannot be added to photographs, and a title cannot be added to the post. Well done WordPress. (p.s. 16 June… captions and headings have reappeared. Hooray!)
I have been tearing out chunks of hair, and gnashing teeth because prints are failing due to loss of adhesion. And the problem has progressively worsened to the point that the failure rate is now 100%.
And I am thoroughly fed up with throwing bird’s nest conglomerations of PLA in the bin.
I have tried the following remedies…….
Varying the bed temperatures and extruder temperatures up and down. Various combinations and permutations.
Cleaning the bed after every print, with acetone and scraping.
Checking and rechecking the bed for level.
Replacing the extruder nozzle.
Changing the PLA to brand new stock.
Printing on a different part of the bed rather than the default centre.
Today, I searched the net for solutions, and I decided that I had tried all of them, EXCEPT, replacing the bed surface.
I have been using a 3M product, designed for 3D printing, designated 9080A. Today I RTFM. If you do not know what that stands for, try “Read the F’ing Manual”. So I RTFM’d.
It seems that 9080A is good only for 10 uses, then should be replaced. OK. Penny drop time. I have been using the printer for 18 months with the same 9080A sheet. Maybe 50 times?
Back to Amazon, order some more 9080A sheets. Meanwhile I will revert to the borosilicate glass sheet that was originally supplied with the printer.
Well, 99% finished. I still intend to make sights, a base, and bumper components. But it now looks finished. A few pics.
It has a few differences from the first one of these which I finished for last Xmas. It has side platforms, handles for positioning the carriage on the slide, minor design changes in the rear wheel brackets, minor changes in the elevation wheel, and probably a few more that I cannot remember.
The explosive projectiles would never have been placed on the side platform. The noses contained impact sensitive detonators, and I doubt that the gunners would have risked them falling off.
The positioning gears work well, as does the elevating mechanism/gears, the elevation lock, the clutch and brake.
Oh yes, some fasteners for the rear platform too… And engraving text on the recoil tube cap, and the muzzle mouth. OK, 98% done.
Now, I am getting on with my next project too. Yes I will eventually finish the Armstrong RML cannon. But I am getting impatient to be doing something different, so I have started on the bronze version of the Ottoman bombard.
This PLA 3D printed breech is 230mm long, plus thread, and 107mm max. diameter. Still deciding whether to refine the design and print another. For one thing, the threaded section is constant diameter, whereas the original had a tapered thread. Yet to 3D print the barrel. It is 280mm long. That is a lot of plastic to burn out prior to bronze pouring. Maybe I should use transparent PLA in case the black dye (whatever it is) damages my burn out oven, or my lungs.
For another thing I have been unable to get my CAD program to convert the Ancient Arabic Script into vectors. But, I have been able to get V-Carve Pro to recognise them/
That is a tracing from the photograph. A couple of hours of effort doing the tracing. Then scanned the tracing, and imported the scan into V Carve. That worked, and I hope to remove 0.5mm of the muzzle bronze, leaving the raised script and stylised designs. V Carve predicts that will take 5 hours on the CNC mill!! Watch this space.
Almost finished the model Armstrong 80pr RML, and just starting another project. I have mentioned it in previous posts…. a 1:10 scale model of the 17 ton Turkish bombard, which currently resides at the Royal Armories Museum, Fort Nelson, Portsmouth, UK.
The original was in 2 pieces, to make the casting process manageable, and presumably to make transporting the monster cannon more manageable. The museum states that another reason for the screw thread join of the 2 massive parts was to separate the halves for reloading, but I can find no substantiating references for that statement. And it does not make sense to my conception of what would have been involved in the reloading process.
At 1:10 scale the model will be over 500mm long, and will presumably weigh approximately 17kg (37.5lb). Each piece will weigh 8-9kg. I will make the model in 2 pieces, for authenticity, and to make the casting more manageable, and to make the 3D printing possible. My 3D printer has a maximum model size of 300x300x400mm.
I spent several days drawing up the breech and saving it as an stl file, for the slicer (Simplify 3D) to process. The slicer predicted that the print would take 51 hours, and consume 697g (1.5lb) of PLA. I used 0.2mm layers, with 8 top, 8 bottom, and 6 side layers, and 10% fill, and since there wee some 90º overhangs, I decided to add supports.
And guess what. The print took 51 hours, and consumed most of a 1kg roll of PLA.
I chose to operate the extruder a bit hotter than normal, at 225ºc, and heated the platen to 65ºc. I wanted to make sure that this print was water tight for the moulding process, and remained adherent to the platen for the duration of the print. I accepted that the detail of the print surface would be a little coarser than could be achieved at a finer layer thickness, but the benefit would be increased water tightness.
The Ottoman Bombard at Fort Nelson. In the background is the barrel for the supergun which Saddam Hussein ordered, but was prevented from being exported from the UK.After about a day of printing. On our dining room table (which I made many years ago).Phew! Printing completed.Most of what can be seen here are the supports.It took about an hour to remove the supports. They were particularly resistant to remove from behind the pins.I will spend a few more hours sanding and filing and filling the surfaces, before making the molds with the investment powder.
I am still drawing up the barrel. Well, actually, it is fully drawn up, but I am refining the drawing of the Arabic script which is embossed on the muzzle. It is quite difficult to convert the squiggles and patterns to vectors, which can be used to produce the STL file for the 3D printer.
The Arabic patterns and script on the muzzle. At 12, 4 and 8 are floral patterns. The calligraphy reads “Help O Allah. The Sultan Mohammed Khan son of Murad. The work of Kamina Ali in the month of Rejeb. In the year 868″. (CE. 1464). p.s. I did not previously notice the alien watching me , top right.
SWMBO and I spent a day at my daughter’s home recently, child minding.
I used the visit to re-examine an old friend. And took a few pics. I had forgotten how nice that first Armstrong model cannon looked. Currently it sits on top of a piano.
The first model has the big wheel for positioning the barrel at the top of the slide, ready for reloading. The second model will have crank handles instead of a wheel. And the projectiles would not have been placed on the gunner’s rear platform.And with the barrel depressed to 19º, and the 20lb powder charge rammed into place, the 80lb projectile is ready to be rammed into position. (the gunner was a bit careless for this photo. The barrel angle is a few degrees off 19º)
I was happy to note that the rewinding mechanism, and elevating gears all work nicely.
So, firstly the cheap epoxy repair/filler. I paid $AUD9.95 for 100g on Ebay.
I note that the price has increased since my purchase, but still a lot less expensive than JB Weld.
I had dropped a tool onto my cheap compressor, and snapped off the muck metal outlet fitting. I tried cutting off the broken bit, re-tapping it, and blocking off the broken bit, but the muck metal part kept on crumbling away.
The broken fitting, after trimming it back with an angle grinder. Fitting a 1/4″BSP plug was unsuccessful.
So, I filled the broken fitting with the Chinese epoxy.
The broken muck metal casting filled with the cheap epoxy.
It took many hours to set hard, and I left it for 24 hours before firing up the compressor. I stood well back, out of the firing line, and powered up at 100 psi. All good. So I left it for a few hours, still all good. So then I did some riveting on my model cannon….
Initial riveting efforts satisfactory. Not perfect but not bad for a beginner.First I riveted the sides of the carriage, then the bulkheads, then finally the base.And then I used a pressure can to paint etch primer onto the sub-chassis, and the carriage. Hides a multitude of errors. My spray booth is a cardboard carton. Also melds steel, aluminium and bronze.The etch primer shows the features which need further finishing, filling, filing, and provides a good foundation for the top coats.
The Chinese epoxy metal repair-filler is inexpensive and works well. Just a pity that it comes from a country whose government ignores international laws, and is territorially aggressive (Tibet, Taiwan, Tajikistan, South China Sea). And has probably lied about the origins of the Covid pandemic.
Camping on the bank of the Murray River was just sublime. Good weather, beautiful surroundings, quiet and solitude, wildlife, brilliant night skies and endless blue day skies, exploring the Hattah Kulkyne National Park and Sunset Kulkyne National Park. Swimming, campfire cooking, good wine and good company.
But all good things come to an end, and wet weather was on the way, so we packed up, and set off home. First step was to negotiate the awful entrance track. 20-30 minutes of vehicular destruction and bone shaking. Off track driving is strictly forbidden to protect the easily damaged vegetation, but boy was it tempting.
We took a longer route home, involving an overnight stay in the western Victorian town of Horsham. That was so we could be at the opening time of the Stick Shed at Murtoa. See my post “Now, This is a shed” March 20 2021. And the route was chosen to see as many wheat silos as possible. North Western Victoria varies from desert to dry country, and the dry country is mostly used to grow wheat. Tall concrete silos dot the towns and countryside, and many of them have been painted.
Nullawil. Wow! It is big, awesome, moving. The first silo art was unexpected, and we quickly became enthusiastic to see more.Mallee fowl sculptures made from corrugated iron. These have real character, unlike most “big” bananas, pineapples, koalas etc etc. Old gynaecological habits die hard.Senior local identities.Local identities. And a couple of tourists (Scott and Libby)This one was painted by a Russian artist, of 2 local sports teens. Timber dray at Mutoa, would have been drawn by bullocks. I imagine that the 17 ton Ottoman bombard would have been transported on a vehicle similar to this in 1453.
The paintings typically take 2-3 months to complete. Cost was not disclosed, but the increased tourism has more than justified the cost. We did wonder if upkeep of the paintings had been factored in.
Returning to model cannon next post. Riveting stuff!
During our 5 days camping on the bank of the Murray River our movements through the 48,000H hectare Hattah Kulkyne National Park were restricted for 2 days because feral goats were being culled by helicopter shooters. Movements along the River Track were permitted, and we never saw or heard the helicopter. On one of those days we drove to Hattah (population 28), then into Sunset Country – Murray Sunset National Park. We drove west, then south to The Pink Lakes, then via Underbool and Ouyen back to our camp on the river. It was a full day trip mostly along rough sandy tracks, and rough dirt tracks. It would be possible in a 2WD, and was easy in the 4WD Landcruisers. It is desert, with no fresh water, except for some tank water at a couple of camping grounds. The lakes on the map are all shallow salt pans. Any water in these is very shallow, and unusable.
North Western Victoria. Ki Bend is just to the east of the “k” in Hattah-Kulkyne National Park”
Des had never driven a 4WD before, but he quickly gained confidence in the Landcruiser’s predictable handling over the rough sandy tracks, and eventually I had to slow him down. The sand was deep sometimes, but never quite requiring tyre pressure reductions. We saw no other people or vehicles in the park and the camping grounds were empty. We did see some kangaroos and emus on the east side, nearest the river, but no wild life or birds deeper in the desert park.
Sandhills, salt pans, blue skies.The serpentine shape at the base of the decorated tree was just a branch.The Pink Lakes were not as pink as I remembered from 20 years ago. Apparently the hue changes with the seasons. The water is just a few centimetres deep.There was a salt extraction mine many years ago. In the back ground are mounds of salt. Quite a bit of slowly rusting machinery.
When our youngest daughter was old enough to be slightly responsible, our family frequently went bush camping on the banks of the Murray River, where it flows through desert country.
No facilities. Just river banks for the tents, the river to swim and fish and yabbie, cooking on campfires. We took a chemical toilet which was located behind a canvas screen. We took drinking water in 20 litre containers. In summer, occasional days were very hot, up to 44ºc. Too hot to be outdoors or in tents. We would drive about an hour and a half to Mildura to shop in air-conditioned centres, or see a movie. But mostly the weather was warm and lovely. Rain was occasional, and could be very heavy.
Often, our family group (2 or 3 families) was the only occupant of the river bank. Sometimes there would be another family group, but privacy was respected, and tents were positioned as far apart as possible. There were friendly nods when passing on the 4WD tracks, or the beach. Yes, there was a beach. At Ki bend, there was a sandy beach about one kilometer long, and 50 to 100m wide, depending on the river height.
A 4WD vehicle was desirable due to the rough access tracks, and essential after rain. The river flood plain was fine clay, and incredibly slippery when wet. Recovering bogged vehicles was a common occurrence. After a few trips I progressed to a Landcruiser with a Warn winch, compressor, snatch straps, tow straps.
The river banks were populated with River Red Gums which extended for a kilometer or 2 away from the river. The red gum dead timber made for long lasting and hot camp fires, ideal for cooking, and evening socialising. The kids quickly learned fire common sense. My youngest became obsessed with fire, and would feed sticks, and watch the fire for long periods. She is still fascinated by fire. (that is the daughter who spent a day with me melting and pouring aluminium to make cannon parts.)
The nights were dark and clear, and we always were blown away by the brilliant night skies. Sometimes I would set up a telescope, or use binoculars, to talk to the kids about stars and constellations, and the moon. We could see the International Space Station quite clearly with the telescope.
The wildlife was wonderful. Large groups of kangaroos and emus. We counted 2000 roos one day! Goannas, and an occasional snake. Wild goats and pigs were visible on the opposite river banks where there was no road access. A half hour drive away there was a ranger station at Hattah, and we would always introduce ourselves to the ranger, and chat about the park.
And the birds! They would start up at dawn, and the squawking was deafening. Sleep was impossible when they commenced. Thousands and thousands of white cockatoos, hawks, eagles, parrots, budgerigars. They would fly off in groups, and return at dusk. Large birds would skim the water and occasionally plunge for fish.
Some days we would cook, eat, swim, play bocce or cricket on the sand, read and read and talk and talk. The kids mostly entertained themselves. The water was shallow and gradual off the sandbank. But we always watched them closely. The Murray is notorious for drownings. There are many submerged dead trees, and the river is constantly flowing.
Other days we would drive through the park to spot animals. And we would have day trips into the Sunset Country. That is true desert. The only water is in salt pans. The trees are low and scrubby. There are many sand hills. Some cattle farms struggle to exist on the margins. There are some operational and some abandoned mines for mica and bentonite. And abandoned iron machinery lasts for decades in the dry environment. We always take 2 vehicles, 4WD’s, in case of breakdown, or irretrievable bogging. And containers of water and food. 4WD is essential in some places due to loose deep sand, where the going is slow, careful, and heavy.
These were wonderful family holidays. When my daughters grew into adults and left home to make their own lives, the Hattah trips stopped, but they often reminisced about camping at Hattah. Lately they have been talking about taking their own children, my grandchildren, camping on the banks of the Murray at Hattah.
Then recently, my brother in law and his wife asked me if I wanted to join them on a nostalgic trip back to Hattah. I immediately agreed, and invited another friend to join us. My wife used to love the camping trips, but her arthritis limits her mobility, and sleeping on the ground is not an option for her. Even an offer to hire an off road camper was not acceptable. So I asked a friend who had never been bush camping, and had never done any off road driving. I was somewhat surprised when he immediately agreed. We are all into our 70’s. My vehicle is still an 80 series Landcruiser, 27 years old. But it is in good mechanical condition. Bull bar, Warn winch, heavy duty springs, compressor, dual batteries, driving lights, and I still have lots of recovery gear. I also still have a “minute” tent, small fridge, cooking gear, etc etc. It was all stored away in case such an occasion would arise. I also packed my anti snoring CPP device, medications, a first aid kit. And I bought a modern innovation, a solar blanket, for recharging the vehicle batteries, to keep the fridge, and my snoring device working. The fridge was for beer, meltables and vegetables. I am now vegetarian, so keeping meat chilled was not an issue.
I also purchased a pair of hand held small walkie-talkies, for communication between the two vehicles. We would be well out of mobile telephone range a lot of the time. In the old days we had vehicle mounted 2 way radios, but mice had got into mine and it was kaput. I was pleasantly surprised how inexpensive the solar blanket and walkie talkies were.
Spent a day gathering gear, and doing some repairs to vehicle and tent. Another half day packing the Landcruiser.
Then we were driving towards Hattah. Met the other vehicle at Gisborne. Crossed the Great Dividing Range, then the flat dry plains of north western Victoria. About 6 hours of highway driving, with a stop for lunch, then past the olive groves, and almond orchards of the irrigation country as we neared the Murray River. Finally we passed Manangatang and Annuello, then onto the dirt track for the final kilometers in the Hattah Kulkine National Park to the Ki Bend.
That track is always rough and bone shaking. But, with almost no use in 2020, and no maintenance, it was horrendous. I have driven the Palm Valley track, the Birdsville track, and other parts of central Australia, in the 1980’s and 90’s, and driven some rough tracks in the Otways before they were all closed, but for vehicle and human bone shaking, this was the worst that I had ever encountered. Deep corrugations which were impossible to avoid. And no speed change was of any help. After about 20-30 minutes of being shaken to bits we arrived at the Ki Bend. The river looked SO inviting. The sand bank was exposed. The river was about medium height. It looked as wonderful as I remembered. And, there was no-one else anywhere to be seen. No other camps. No vehicles. No boats. Deserted.
However there was a problem.
The camping sites were basically areas cleared of bushes and grasses, and not directly underneath river red gum trees, which are notorious for suddenly and randomly shedding huge heavy branches, killing or maiming anyone silly enough to be underneath. But, the sites were choked with tree saplings up to 3 meters high. We guessed that they had grown in 2020, in the absence of campers.
Camping on the sandbar on the River Murray. “Minute” tents take about one minute to erect. My friend Des. River red gums.
We could have removed the saplings, just enough to put up our small tents, but somehow, it did not seem the right thing to do. The other option was to camp on the sand bar. And that is what we eventually did. Small biting insects on the sand bar did not prove to be a problem. We were well away from potential dropping red gum branches. We could drive our vehicles on the firm sand near the river bank. And there was plenty of dry dead wood for the fire. We figured that if the river did start rising due to water release further upstream, we would have time to pack up and move to higher ground.
So, we put up our tents, including the toilet tent, dug a pit in the firm sand for the fire, gathered some wood and lit the fire, unfolded our chairs, and had some beer. By this time, dusk was approaching, the birds started squawking and settling into the trees, turning them white.
Our campsite is just visible in the shade of the trees.The next day we were thoroughly relaxed. Des, Scott and me. Libby took the pic. When the river is high, the sandbank is totally covered. We have seen the river topping the banks, but not for many years.
This list is more for my own amusement than expecting much reader interest. It is a list of the materials which I have used in making the model Armstrong RML’s.
Mild steel (most of the structural components, barrel 2)
Stainless steel (barrel 1, wheels, and metric fasteners)
Tool steel (rifling cutters)
Bronze – LG2 (ingots for casting many small components, bar stock for machining small components where possible)
Brass (some small components)
Copper (rivets, gas checks)
Aluminium (ingots for casting wheel brackets, bar stock for CNC jigs)
Jarrah (floor board offcuts for platforms)
gas struts (adapted for use as the recoil mechanism)*
And the processes…this was prompted by a question from my daughter.
Photography (still, video, drone)
Linear and angular measurement of the original cannons
pencil sketching
3D printing (new skill for this project)
CAD design 2D and 3D
Discussions via web site, email, telephone, face to face with historians, cannon enthusiasts, black powder enthusiasts, model engineers, mechanical engineers, computer experts, CAD experts, museum curators
Conventional machining with mill, lathe, drill press, hand tools
CNC machining with mill, lathe, rotary table (new skill for this project), using Mach3, Vectric V-Carve Pro.
Gear design and cutting (using Gearotic software-new skill)
Silver soldering
Solid Riveting
Woodworking (minimal)
Casting aluminium, bronze (new skill for this project)
Having mild steel and tool steel parts laser cut professionally
Designing engraving of symbols, alpha numerics, lines, labels etc. and completion of these with a fibre laser by Stuart T.
Purchasing parts from suppliers during Covid restrictions, mostly by telephone and online
Making tools, particularly a tool to cut rifling grooves. Quite proud of that one.
Metal filling (JB Weld), gluing (Loctite, Super Glue), finishing, polishing, painting, lacquering.
Keeping detailed records in notebooks, photographs, videos.
Completing this blog, answering correspondents. This has been a very rewarding aspect for me. I have had lots of advice, all of which was appreciated, and some which was used and acknowledged. When I aired doubts about difficult or dubious decisions I particularly valued the feedback and encouragement from my readers.
I have made many mistakes. Some required making new components. Some required honing skills (like riveting). Some were camouflaged. Some were just accepted and ignored and eventually forgotten.
The models were a significant cost. The biggest item was the metal casting equipment, which I can use on future projects, and probably sell one day, so I will exclude that from calculations. Same goes for the 3D printer. I did not keep actuarial records of costs. I used several bags of metal casting investment medium at $110/bag. Bronze and aluminium ingots were also several hundred $$ but I have quite a bit left over. BA fasteners were ~$200. Metric fasteners were inexpensive, from China. Laser cutting was cheap $~60. Most of the metals for machining were from my workshop stock, so not included. I have spent about 15 months making the 2 model cannons. The power bills for my workshop are about $250 per 3 months, so that cost component is significant.
The biggest cost was the time taken. I roughly estimate 25 hours per week (conservatively, could be much higher), over 60 weeks. Say 1500 hours for the 2 model cannons. (not including finishing number 2. Probably another 50-100 hours). So, maybe 800 hours per cannon, not including research time, trips to Port Fairy/Warnambool/Portland/Queenscliff, etc).
Hmmm. Maybe I should not have done that rough cost estimate.
Not sure if I will publish this one.
*Using gas struts was a controversial decision. The commercially available gas strut was 0.5mm bigger diameter than specified (18mm instead of 17.5mm), exactly the correct length after a bit of machining, although the piston rod required lengthening by 30mm, the right colour, and too stiff so I released the compressed gas. Some of my model engineering colleagues were a bit sniffy about it, but it fitted the bill closely enough for my liking so I used it. No regrets. I also buy fasteners where possible. I rarely make nuts and bolts although I often modify commercial ones. I use metric fasteners where possible, although there are a lot of BA8’s and some BA 10’s in the cannons. I broke x3 BA8 taps but all were able to be removed.
A few year years ago I made a model triple expansion steam engine with plans and castings supplied by EJ Winter P/L of Sydney. The details of the build were detailed on this blog. I found it to be a difficult build, but eventually got it running on steam, as shown in the following video…
Today I rang Ben deGabriel, the owner of EJ Winter P/L, the supplier of the plans and castings of the engine, to order some 10BA nuts and screws for my model Armstrong RML cannon. It is always a pleasure to chat with Ben. He is so passionate about model engineering, and a very knowledgable and reliable supplier. The chat turned to the triple, and he told me that he had found references on the original model engine plans, to SS Kuttabul, the engine of which was the basis for the model engine.
The SS Kuttabul was built as the largest K class ferry for Sydney Harbour, and first in service in 1922. Kuttabul is an aboriginal word meaning “wonderful”. The Kuttabul had a passenger capacity 0f 2250, which is the largest of any ferry ever in service on Sydney Harbour. It was 183′ long, beam 36′, and gross weight 448 tonnes. Steel construction, and with 18 water tight compartments was regarded as unsinkable. It had a 113hp triple expansion steam engine.
After the outbreak of WW2, the Kuttabul was requisitioned by the Royal Australian Navy, and was moored at Garden Island in Sydney Harbour, and used as accomodation for naval personnel pending transfer to their ships.
Three Ko-hyotkei class Japanese midget submarines entered Sydney Harbour 31 May 1942, with the intention of sinking Allied warships. M-24 fired 2 torpedoes at USS Chicago, a heavy cruiser, but both missed. One torpedo ran aground harmlessly, but the other hit the breakwater against which HMAS Kuttabul, and a Dutch submarine were moored. An alternative conclusion is that shells from the USS Chicago which were mistakenly aimed at the Dutch submarine, hit the Kuttabul. In either case, the Kuttabul broke in two and sank, killing 21 sailors, and wounding another 10.
The engine of the SS and HMAS Kuttabul, was a 113hp triple expansion steam engine.
This history, whatever the exact cause of the sinking, makes me particularly glad that I modelled this particular steam engine.
If I find more information about the Kuttabul or her engines I will add to this post.
Most parts are made. A few refinements and modifications still on the list. My sister in law is impressed, and took the first photo below.
About to commence the teardown, for final rivets and other fasteners, and some paint and lacquer. And the sights.The undercarriage, slide and platforms and gear train, carriage with recoil cylinder, elevation gears, barrel, stops, handles.
When the cannon was fired the recoil pushed the carriage up the 4º slope of the chassis. However, to reload the muzzle loading cannon, the carriage had to be completely at the top of the slope. I know this, from making the model. There is only one position of the carriage on the chassis where the loading arm will properly engage with the muzzle of the barrel.
So, if the recoil did not push the carriage up to exactly the correct position, it had to be wound up to correct position by 2 of the gun crew, operating a handle or wheel on each side of the chassis.
On the first model which I made of the cannon, I copied the wheels which were present on the original cannons at Warrnambool.
One of the Warrnambool 80pr Armstrong cannons, showing the 1 meter diameter winding back wheel.
Of the seven 80pr Armstrong cannons which I have been able to examine, the Warrnambool pair are the only ones with existing winding back wheels or handles. So that is what I made for the first model which I made, and what I had planned and made for the 2nd model.
The second model Armstrong 80pr, which I am making for myself. With winding back wheels. They look interesting. But are they original, or later fanciful interpretations?
But, I was always a bit dubious about the large, and rather unwieldy wheels. Would the original Armstrong designers have specified such wheels? Then one of my readers independently questioned the wheels, so I delved more deeply.
The 80pr cannon is essentially a copy of the 64 pr Armstrong cannons, the main difference being in the construction of the barrel. The 80pr barrels used the new method of winding white hot strips of iron around a mandrel, which made them able to accept larger charges of gunpowder, and heavier projectiles.
I could not find any plans or diagrams of the 80pr cannons, but I did find these drawings of the 64 pr’s on a very similar iron chassis….
The dimensions of the 64pr are similar to the 80pr. And can you see the winding back handle, at the front of the winding back gears? It is certainly not a wheel.
So, I have made handles for my 2nd model…..
See the handles? They look the part, No?
Then, the instruction manual for the 80pr, which I saw for the first time a month or so ago, specifies that after winding back, the HANDLES are laid under the chassis. Not the WHEELS, but the HANDLES.
A copy of the original operating manual for the 80pr Armstrong RML cannon on an iron slide.Page 6 of the operating instructions. Fluoro highlight added by me. “winch handles” could still be the large wheels.Page 10 of the instructions. I really doubt that large wheels would have been easily laid down under the slide. I am fairly sure now that crank handles would have been used. Much easier to use, to remove, to lay down, then replace. Even on the model, the crank handles are easier to use than the big wheels.
So, I rest my case. Crank handles it is, unless some other convincing evidence comes to hand.
P.S. Casting the Chess Men. I am still feeling a bit despondent about that last failure. I have some ideas about better techniques, but I am not moved to try again. At least at present. For one thing, the failed pieces are really quite heavy, and I wonder whether even if successfully made, they would feel good to use. So I am moving back to finish the cannon, and will wait see if there is some inspiration to redo the chess men. Also, I am still fixing the CNC lathe with the dead computer. Have changed the interface to a smooth stepper, and laptop, but there are still some issues. Stuart T installed the smooth stepper, and reconfigured Mach 3, but the smooth stepper would not work. So Stuart used another identical smooth stepper board, and that works. Stuart is still trying to figure out whether I bought a dud smooth stepper board.
Today I poured 3 cylinders of brass to make 12 chess pieces. 8 pawns and 4 rooks. It was a total failure.
A model engineering friend had donated 3.3kg of brass, in the form of spent cartridges.
First a wash in hot strong detergent..Meanwhile the cylinders were going through drying and baking cyclesand approximately an hour before the cylinders were finished, the cartridges were melted at 1070ºc….that is hot!then poured. All straightforward so far. The egg yolk in the middle is actually hot fluorescent orange as in the previous picture.but after removing the investment medium, the brass figures are disappointing. Poor surface detail. Left over brass melt ingots in the background.… lots of surface bubbles, and voids. They do remind me of walking dead zombies.and the rooks are similarly disappointing, with poor surface detail, voids and bubbles.
This is the first pour which I have done in 3-4 months. It was ambitious, requiring 3.25kg of investment powder, and 3 large cylinders. But these pieces will all be redone, with new 3D prints, and recasting. The failed pieces will be remelted.
I think that the main problem was that the investment mixture which I painted onto the prints was too thick, and did not penetrate all of the surface features. And the painting was not adequately thorough, leaving bare areas which predisposed to bubbles.
And the main bulk of the investment mixture was too thick. I did mix it a bit longer than usual because of the volume involved, and I did notice that it seemed more viscous than usual, and when vacuumed, the bubbles never really stopped coming.
The voids occurred mainly at the bottom of the cylinders, which indicates I think, a need for ventilation tubes. I had stopped using those for bronze pours, but maybe for brass they are necessary.
So, at this moment I feel that it was a wasted day. But I have learned some things, and have a plan for the next pours.
And I was very satisfied with the quality of the brass from the cartridges. Hopefully that will continue as a source.
OK. So I hope that you saw the pics of 3d printing the pieces, then making some trees using the PLA pieces, wax parts, steel cylinders etc.
Today I mixed the water and Jewellers Investment powder, and poured the mixture into the cylinders. This was the largest volume of mixture that I had attempted.
1.5kg water, and 4.25kg of investment powder.
I keep a record of every mixture, every metal pour.The rubber tub is for the mix. The vacuum pump and container are to extract as much air from the mixture as possible. The pump is 1hp.Making the mixture, degassing it, and pouring it, is a tense time, so no pics. This shows the scales for measuring the weights of the water and investment powder. I use some old beaters to do the mixing. The degassing. Then pouring into the cylinders.After an hour or two, the rubber base is removed, showing the trunk of the wax tree, and the metal pouring funnel.
The cylinders are placed in the potter’s oven. I have set the timer to commence the burnout at 6am tomorrow, at 250ºc. The funnel is upside down, so any melted PLA of wax will run out onto the bench. I leave a slight gap in the door closure. I will arrive at about 9am and complete the burnout at temps up to 750ªc, then do the metal melt and pour 4-6 hours later. Wish me luck!
Since New Year I have been slowly completing the model Armstrong 80Pr RML cannon which I am intending to keep for myself. The first example was given as a present to my daughter and son in law.
I expected that the 2nd example would be finished much more quickly than the first.
After all, most of the difficult design, casting, and machining decisions had been made first time round. And I had made extensive notes, diagrams, and photographs first time round.
However, there were a few obstacles to rapid completion…..
I had made some design changes. Always risky. Always time consuming.
I could not find some notes and photographs which I was sure I had carefully filed away.
I could not remember how I had made some tricky small shapes, and had to reinvent some methods. In some cases that triggered a memory of the first method, and I realised that I had reinvented the first method.
SWMBO had other ideas about the best method of using my time, and making model cannons did not enter her equations.
I made some brand new mistakes, which had to be rectified.
But, here I am, very close to final teardown, and then for final assembly and completion.
With respect to final painting, finishes etc. SWMBO has made a strong pitch for the same finishes as model 1. My inclination was to aim for authenticity, and paint most of the model. SWMBO wins, as usual. “It has to look interesting and beautiful, not boring black.”
So here are some pre-teardown photos.
Hmm. That kitchen table needs re-polishing too! The side platforms are an extra feature on model 2.I redesigned the rear wheel brackets, and cast them in bronze. Looking at this photo reminded me to do some more finishing on the casting, and to make more authentic looking axles.…and to remake the rear wooden platform. The screws are too big for the scale. And to make sights for both models.….and to finish making the loader….and the riveting. My riveting technique has improved, no? Note the redesigned bracket for the recoil tube, and the redesigned elevation handle. (You probably don’t remember what these looked like in model 1.)
Almost finished the kitchen for SWMBO, so I should be free to finish my Armstrong 80pr RML in the next few weeks.
Meanwhile the computer which runs my CNC lathe went “bang” when I last turned it on, and it is dead. It is close to 20 years old, and it lived in an environment full of dust, swarf, mice, damp, and the odd tiger snake. Originally ran on Windows XP (some of you remember that one?). So I will install another oldish laptop to run the lathe, and will change from the parallel port interface to a “Smooth Stepper”, thus joining the 21st century. (I do hope that Stuart, my expert friend, is reading this.)
Very few posts lately. SWMBO (SHE who must be obeyed) has me assembling and installing another kitchen. I have lost count, but I think that this must be the 7th or 8th. And the problem is that I showed some aptitude for the job with the first one, and have got better with each successive one.
It is not that kitchens are not important. I get that. It is just that I would prefer to spend my time making model cannons and casting chess pieces.
But. “Happy wife = happy life”.
I was in a similar position under the Port Fairy Armstrong not so long ago. That was more fun.
2 trees of pawns. Standing in front of their casting cylinders.And 4 castles. Obelisks actually.inside their casting cylinders. Remind you of anything? Chinese warriors for example?
Next step, to paint the PLA models with investment medium, then fill the flasks with medium and let it set overnight.
Incidentally, I tried several methods of cleaning up the PLA.
Soaking in acetone – waste of time.
Sanding and filing- effective, but very time consuming.
Using a heat gun – caused the entire model to heat up, with resulting distortion.
Using a flame gun, propane torch – very hot, so extremely brief exposure, maybe 1 second. This was my best method. It melted the tiny zits, burned the loose strands and removed some, and made the rest easy to finger nail off. A bit tricky. You don’t end up with much hair on your hands.
I tried a new technique for making a brass label. I hasten to add that the technique is new only to me.
The label after engraving on the CNC mill
This is my engraving setup. A 26,000 rpm 2kw head, clamped to the main spindle, and controlled independently. The Z and XY axes are controlled separately by Mach 3. I turn off the main spindle to avoid embarrassment.Using V-Carve Pro to generate the G code, and Mach 3 to run the mill. 90º V bit, run at 18,000 rpm, 100mm/min. Not a bad result. Not perfectly centered. I will mill off 1/2 a mm on the rightThen a coat of gloss paint. That looks interesting, no? The paint does not adhere to the sharp edges. I might use that as another technique in the future.The surface paint is removed with 600g wet and dry, leaving the paint in the engraving.
The contrast of the black on brass makes the wording easier to read.
BUT. I should have waited for the paint to dry completely before sanding it. Some of the dust has been embedded in the still wet paint, reducing the gloss and making it a bit dull and fuzzy.
Also, the surface needs to be finished with a finer grade of wet and dry. Then lacquered.
The white pieces were printed several weeks ago, then the black pawns. But I had 2 failed runs when printing the black major pieces. The failures seemed to be caused by failed adhesion of the pieces to the platform. In each case, the runs were progressing nicely, but failed after about 20 hours, in the middle of the night, covering the 7/8th completed pieces with PLA spaghetti.
The settings were exactly the same as the white pieces, so why the sudden failures? Is the black PLA different in some way?
So I asked my colleagues at the GSMEE. (Geelong Society of Model and Experimental Engineers), some of whom are experienced 3d printers. It was suggested that perhaps I had turned on the cooling fan too soon, after layer 1. So I changed the setting so the fan did not come on until after the platform and one layer of the pieces had been completed. And the result was excellent! See the photo.T
The black pieces, after a quick clean up. A successful run, which went for 26 hours.
Of course the colour of the PLA is irrelevant. The PLA will be melted, vapourised and burned out after the molds are made. But I could not resist the opportunity for a photograph.
Next, to make the wax and PLA trees, and make the molds.
Still thinking about what metals to choose, and how to colour them. The pieces could be used just as they are, but I really want to feel the weight of real metal pieces.
And although I claim that the 3d printing is complete, the assumption is that there will be no casting failures. I could well be printing more pieces.
I have been bush camping for a few days on the Murray River. About 550km from home. Ki Bend, Hattah-Murray National Park. I might write about it in a later post.
On the way home I visited a shed at Murtoa, a small, pretty town in the wheat belt of the Wimmera. It is called the “Stick Shed”. Sometimes called the “Wimmera Cathedral”.
The exterior is large, but drab and rather boring. Rusting corrugated iron roof with some repaired sections.
It IS large. 270m (870′) long, 60m (196′) wide and 20m (65′) high.
Australia is a grain exporting nation. During WW2, shipping exports were dangerous, and limited. For obvious reasons there were no exports to Japan. And we had some bumper harvests. Anticipating a large harvest in 1941, 26 of these huge storage facilities were built. This one at Murtoa was the first, and is the only one remaining. It covers 4 acres. The largest facility covered 10 acres. The Murtoa facility has not been used since 1989 and it was falling into serious disrepair. The owners wanted it demolished, but activists lobbied to have it preserved and in 2014 it was placed on the National Heritage Registry. Substantial repairs have been undertaken.
The interior is awesome.
There are 560 mountain ash tree trunks up to 20m long, supporting the roof. Many have been repaired with concrete bases, steel supports, bolts and trusses. Some have been replaced with steel posts, because suitable tree trunks are difficult to source. Lighting is through skylights and some wall windows. The floor is 4″ thick concrete.
Wheat was piled high, up to 92,500 tonnes, right up to the top of the roof. The roof angle was determined by the “natural angle of repose” of the piled wheat. Delivered by truck or train. The wheat was elevated by conveyors, powered by a steam engine. Initially the facility was vermin proof. Workers could walk on the surface of the wheat, despite sinking up to 500mm and vermin sprays and ventilation prevented infestation.
Conveyor belts ran the length of the shed at the sides, and were used to load wheat onto railway wagons.
Some old photos were on display.
The posts were placed in holes 4′ deep. Top right.. the pile of wheat.
The construction was completed in 4 months. The facility was full within 6 months.
If you have the opportunity to see this amazing building, just go.
Each piece takes 2.5 – 4 hours to print at the high resolution which I require to produce a good finish. The printed pieces will be attached to a tree, then encased in jeweller’s casting medium inside a steel cylinder. When set, the cylinder is heated to 200-300ºc to melt and vaporise the PLA, producing a cavity in the casting medium, into which the molten metal will be poured. The mould is baked for about 6 hours to thoroughly dry and harden it before the metal is poured into it.
There are 16 pieces in each army of a chess set. So 64 hours of printing for each colour. Plus failures. So far, in about 5 days of printing, I have produced the whites. That has taken almost 1kg of PLA, one roll. PLA is not expensive. I paid about $AUD22 per roll, including postage. Lately prices have risen to around $AUD30 per roll.
These are examples of a print run failure. This run was almost completed after 24 hours, when for some reason it just stopped. It was overnight, possibly a short power outage. Another run failed due to poor plate adhesion, again near the end of a run. I solved that issue by turning up the temperature of the extruder to 220ºc and the temperature of first few layers of the platform to 70ºc.An army of pawns. One spare.Half ready for casting. Now printing the opposition (in black PLA, only because that is what I have on hand, plus it might be another photo opportunity.). Can’t wait to see these in aluminium and bronze.
I have been teaching my 5 year old grandsons to play chess. It started with checkers, but the little buggers are already beating me at that! So I have upped the ante and introduced chess.
Then I thought that a chess set might make a nice present. So I explored THINGIVERSE and found these Egyptian styled pieces. Free download. And I have been printing them. I intend to cast them in bronze and aluminium.
This obelisk is a castle.Queen on the right, knights on the left. Printing in progress so the supports are yet to be removed. Behind are the bishops and the king.
The detail and quality of these Thingiverse STL’s is superb!
In December I experienced several days of feeling unbalanced, staggery. A bit like being tipsy, but no alcohol involved. It passed after 4 days, but I attended my GP in the New Year for a checkup, and mentioned the experience. He arranged the MRI (magnetic resonance imaging) of my brain. 2 weeks later I was wheeled into the MRI magnet, and after 30 minutes of mechanical clanking and banging, it was over. No big deal. I was sure that it would all be normal.
Somewhat to my surprise, the MRI was reported that I had experienced a small bleed in my brain, a stroke, a cerebrovascular accident. A disease of old age. (70). No residual effects this time. But might happen again. It seemed that I might get the answer to THE BIG QUESTION sooner than previously anticipated.
Must get that model cannon finished!
But there is more to this story….
I am not a radiologist. Not even a registered doctor since retirement. But I could not see a bleed on the pictures. Oh well. You have to trust the experts. And gynaecologists are not renowned for their expertise in neurological radiology.
Then, as recommended by my GP, I consulted a specialist neurologist, and had a very thorough neurological assessment. He could find nothing abnormal. An interesting part of the assessment was a cognitive test, apparently the same one that Donald Trump took, after which he announced that he was a genius. Apparently I passed. It was laughably simple.
Most interestingly the neurologist could not see the bleed on the films. So then the films were examined by another specialist radiologist, and he/she could NOT see the bleed.
So, either the diagnosis was debatable, or non existent. The original symptoms were too vague to be diagnostic.
It just demonstrates the old adage. If in doubt, get another opinion.
Apparently the MRI set most of the nucleii in my brain spinning. See the following YouTube video. Sabine Hossenfelder is a German physicist and a brilliant teacher. Worth checking out her other YouTube videos.
Since then I have had no recurrence of the original symptoms.
One of the Armstrong rifled muzzle loaders at Warrnambool
The manual/handbook is undated, but it was printed for the Warrnambool Battery, and lists the iron carriage and slide, so that dates it after 1875. Before that the slides were wooden.
The following is my precis of the interesting specifications. A full copy of the Handbook is available on request
The weights given are: barrel 80cwt, carriage 41cwt, slide 74 1/4 cwt. So, the total weight of the cannon = 195.25cwt = 9.92tonnes (9.76 UK tons). That is the only document which I have discovered which specifies the overall weight, it is interesting to me because it explains why my model weighs close to 10kg. 10kg is close to 1/1000th of the full size weight, which is what is predicted from the model 1 in 10 scale!
Other specifications include: calibre 6.3″; total length 9’6″; 3 rifling grooves with a twist of 1 in 35 calibres, vertical vent 6″ from end of bore.
The sights are located only on the right side, and the tangent site is angled at 2º to the left. (to compensate for the projectile deviation resulting from rifling).
The hydraulic buffer piston had 4 drilled holes. The diameter of the holes was determined by test firing. The cylinder was filled with SOAPY WATER, (not Rangoon oil, which other cannons used).
The slide is of iron, except for the top ‘T’s which are steel.
The brake band permits the carriage to run back, and tightens automatically after recoil to retain it. A hand brake lever controls running up. (? should be running down?).
Barrel elevations: 5º down, 30º elevation, 19º down for loading. (Oops. I had set 17º as the loading angle. Hope that is not a hanging offence)
Charges: Full 20lbs; reduced 16lbs 12lbs, saluting 8lbs.
Projectiles: Studless. With gas checks. (which is further evidence that the manual is post 1875). 80-86lbs,
Fuzes: Percussion or timed (15 seconds).
Penetration of wrought iron plates: At range 0 – 8.5″; range 1500yds – 6.75″; 3000yds -5″; 4500 yds 4.25″.
The manual then lists the procedures for the gun crews. I will summarise those in the next post.
Page 1 of the Handbook for 80pr RML GUN.
with grateful thanks to Marten Syme, historian, for sending me a copy of the handbook.
The elevating gear is a quadrant gear, and it is centered on the trunnion centre. This is how I set it up on the model Armstrong RML 80 pounder. There are probably other better ways of achieving the result, but this is how I did it .
The barrel is removed from the carriage, and a round bar sits on the trunnion caps. The round bar is 20mm diameter, the same as the trunnions. The quadrant gear sits in position, and external calipers measure the distance from the quadrant gear to the exterior of the bar. The position of the quadrant gear is determined by its passage through the front transom. The rear position is determined with the calipers at the same setting.The calipers measure the identical distance, at the front transom. The quadrant gear must be in the correct position. It is Super glued into position after marking.Then the bracket which joins the quadrant gear to the cannon barrel is roughly positioned X,Y and Z. When satisfactory, the position is marked. It all lines up. Next the BA8 fastening bolts will be drilled and tapped.
This is the second 80pd Armstrong RML model which I am finishing, this time for myself. It should be straight forward, having done it all before, but it is like a new adventure. Ah the joys of memory loss. Everything is new.
Actually, the full title of the book is “Treatise On the Construction and Manufacture of Ordnance in the British Service prepared in the Royal Gun Factory” by John Fletcher Owen. Originally published in 1878.
The book is available in electronic form, free of charge, at Google Books. It may be read electronically, or downloaded to your own computer. Owen, J. F. (2018). Treatise on the Construction and Manufacture of Ordnance in the British Service Prepared in the Royal Gun Factory. United States: Creative Media Partners, LLC.
But, I really prefer to read books with the feel of paper, turning real pages, leaving bookmarks, making annotations. So, I ordered a hard back copy of the book from Booktopia. It came yesterday. Cost was a bit less than $AUD50.
I received an email that my order was “being printed” and that it would be sent within 2 weeks. It did arrive about 2 weeks later, and I was surprised to see that it had been printed in Australia! The binding is neat, and the feel is substantial. 510 pages.
Having looked at the electronic version I knew that the book is full of detailed information about the design, manufacture, construction, testing, and use of British artillery of the 1870’s era. Readers of this blog will understand my interest in the subject. There are many, many diagrams, plans, tables. A real cornucopia of information for the cannon modeller, or gun nut.
Now, understand my disappointment when I opened the book at random, to read …. anything. And I blinked and squinted, and tried to make out the words…..
THE TEXT FONT IS TOO SMALL!
With my glasses on, in a good light, I can just make out the words, but it is a struggle, not pleasant at all. And, the margins are huge! 30mm on the right! In the photo you can see the original page edges. They could have made the printed page and font size substantially larger. The reproduction result is a bit fuzzy, not sharp, which compounds the problem.
Compare the electronic version with a page from the reproduced book.
Electronic Version:
Printed (reproduced) Version.
Look at the dimensions in the printed version. Not at all clear. The small size, and degradation due to the reproduction process makes this book less useful.
The 143 year old book is a real treasure trove, and the information and diagrams etc may be freely reproduced without fear of copyright infringement. The reproduced paper version from Booktopia is disappointing. With a little more care it could have been wonderful. As it is I would give it a 5/10. I have sent feedback to Booktopia.
Some random pages follow, just to show more examples of the contents.
So, love the original book, disappointed with the Booktopia reproduction version. End of whinge.
The Royal Gun Factory. Originally established by Henry VIII as an artillery testing range, became the Royal Gun Factory in 1671, and became the largest cannon producing factory in the world by the time of WW1. It is located next to the Thames, in the London suburb of Woolwich, 8 miles from the centre of London, but originally it was a separate village. At its peak, in WW1 it covered 1300 acres and employed 80,000 workers. It closed in 1967.
You can see why they didn’t want it near the centre of London.
Mainly I wanted to show you some interesting images from the era of black powder cannons.
The steam hammer, installed 1874, has a downward pressure of 1000 tons.The component being forged is red hot, and held at the end of the weighted lever. No idea what the worker near the hammer is doing, but it would be hot work.Man power and steam power (oops, my bad. This steam hammer was in James Naismith’s foundry in Manchester, 1832)They also manufactured artillery shells (studded type shown here, so presumably 1865-1877), and small arms, naval and garrison cannons.and the lathes were suitably sized. Sketched in WW1.
(provided you have access to a VERY large factory, and a very skilled workforce.)
This 450 page book is available for free download at Google Books. It is so interesting, and useful to this model cannon maker that I have ordered a hard-back copy to be printed and sent to me. Not overly expensive at just under $AUD50 inc postage.
Everything that you could ever want to know about making cannons in 1879. And more.
For example, I have read descriptions of the Armstrong method of making cannons with iron bars, by forming red hot spiral coils, then pressure welding the coils into a solid mass. Then using a massive press to join the sections together. But how were the trunnions formed?
This drawing comes from the book. The 100-150 foot long strip of ductile iron emerges from the furnace at the back, and it is wound around the mandrel on the left, while red hot, to form part of the barrel shape.The “coils”, while still red hot, are press welded together. A medium weight cannon like the Armstrong 80 pounder would typically have had 4-5 pieces, while a large one, such as the 100 ton 17.8″ bore monsters at Gibraltar and Malta would have up to 14 component parts. The trunnion ring was usually forged from a single lump of iron.The piece which became the bore of the barrel was pressed into place while the outer coils were still red hot, and held in compression when they cooled. Strips of iron are strongest along their length, so the coil method of construction was substantially stronger, and allowed larger charges of gunpowder, heavier projectiles, lower flatter, more accurate trajectories. When steel became more available after the 1870’s, it became the metal of choice for the rifled bores.The bore itself was then rough bored…….and then fine bored, using the technique invented by Wilkinson ~1800. Interestingly, the cutters are steel, and the guides are lignum vitae.Forging the trunnions from a solid lump of red hot iron, using a steam hammer. Alternatively the trunnions were forge welded into bored holes. I was happy to read that, having silver soldered the trunnions into holes on my models.This is a schematic of a 64 pound Armstrong RML. The 80pdrs were almost identical, tests having shown that the 64 pd barrels built this way were capable of handling the larger charges and projectiles. Note 4 separate coils, plus trunnions, plus cascable, plus steel plug and copper washer at the breech end of the bore.The tapered powder chamber was formed with a broaching head.The biggest muzzle loader ever built? Depends how you measure it. Not the biggest bore, but probably the most powerful, longest range.This is 20 years later. The Royal Gun Factory, Woolwich. No muzzle loaders in sight.
I have had this round column mill-drill for quite a few years. The head and the table are both able to be raised and lowered with a rack and pinion operated with a handle. It is a heavy unit, and raising the head or table by hand has always been a struggle, so much so lately that I have been planning to motorise the movements.
There are a few YouTube videos on the subject, but none for my particular setup. And both the head, and the table with its XY table and milling vice, are very heavy. I decided to really gear down the mechanism so the motor could be compact and not overloaded. So that meant another worm and gear in the train. I ordered a 1:40 worm and gear, but meanwhile a friend offered me one from his junk box, which I happily accepted. (thanks Stuart.)
A powerful, reversible, compact motor at a reasonable price, and not requiring complex wiring, is not readily available. But, then I thought, how about trying a reversible electric drill, with speed control? I have a Metabo 750w drill, and I decided to try that. If it worked I could buy another one on Ebay for about $AUD250. As it turned out, it is so easy to attach and detach the drill, that I will probably not need to buy another one. (note added March 11. I bought a second hand Metabo drill on Ebay for $30! It is very second hand, and battered, but has forward and reverse, 2 speed gearbox, and variable speed regulated by trigger pressure. 600 watts. Works like a charm!)
The next decision was whether to attach the motor to the head or the table. My original plan was to attach it to the head, but on testing the power required to turn the handles manually, it was obvious that the table was easier to move, so I have positioned the head at its maximum height, and will probably never need to move it again. The new mechanism was installed on the table.
The following video summarises the assembly of the components, and a brief demo. Click on the arrow to view it (10 minutes duration), or go to YouTube to see it full screen. It was shot on my iphone held vertically.
The cannon construction techniques which were pioneered by William Armstrong in the 1860’s led to more powerful and more accurate weapons. The 6.3″/160mm bore cannons which were shown in yesterday’s post, (and modelled by me,) were rapidly followed by larger cannons. The larger cannons were required to counter the iron clad steam ships which were replacing wooden warships. The colony of Victoria purchased 9″ muzzle loading black powder cannons for the defence of Melbourne, and yesterday I visited Williamstown to see 4 of them.
The 9″ rifled bore cannons fired projectiles weighing 300lbs! Cannons of this size were described according to the bore diameter, in preference to the weight of the projectile.
A fort was constructed at Williamstown (Fort Gelibrand), and 2 of the cannons are located inside a military establishment, unfortunately not accessible to the public.
As seen from about 20 meters, through the fence. Muzzle loading 9″ monsters. The projectile seen is said to be stuck there.
I was sure that I had seen some photographs of similar guns at Williamstown which were accessible so I asked some locals, and was directed to the foreshore.
That is Melbourne CBD in the background.
These 9″ guns are rifled (6 grooves), made in 1867, and muzzle loading blackpowder. They are very similar to the 10″ guns which were mounted on the monitor HMVS Cerberus, but these are garrison mounts whereas the Cerberus guns were rotating naval mounts.
The 300lb projectiles were loaded using a gantry which was mounted on the end of the barrel. The gantry mounting point can be seen as the small holes in the side of the barrel.The loading gantry can be seen in this old photograph of one of the 9″ Armstrongs when it was located at Fort Queenscliffe.A feature of the 9″ cannons was the “Elswick” recoil control mechanism. These substantial strips of iron extended the length of the chassis, and shorter pieces of iron were hung from the carriage to provide friction control of the recoil. The degree of friction was controlled with levers which adjusted the spacing of the strips.Unfortunately most of the elevation control mechanisms are missing. The small bracket top left was probably to hold the steel rod which was used to perforate the gun powder bag after it and the projectile were positioned.6 rifling grooves. The projectiles 1867 to 1877 would have had studs to match the rifling. After 1877 the projectiles would have used copper gas checks to engage with the rifling. The inner and outer coil layers of the chase of the barrel can be seen if you look closely.The 9″ guns were manufactured at the Elswick works, Newcastle, England. and the Royal Gun Factory Woolwich England. The gunmetal trunnion caps are original. If you look closely at the barrel surface you can make out the outlines of the strips of iron which formed the coils.
HMVS Cerberus is a topic for future posts. An excellent source of information is found at http://www.cerberus.com.au
There were only 25 Armstrong 80pd rifled muzzle loaders made, all in 1866. A special order by the Victorian colonial government to the Royal Gun Factory at Woolwich, England. Until today, I had seen and photographed 5 of them. 2 at Warrnambool, 1 at Portland, and 2 at Port Fairy. I believe that there are only 10 still in existence. Today I saw 2 more. These are in the Hopetoun Gardens, in Elsternwick, Melbourne. They are on wooden slides, and have wooden carriages. The wooden components have been repaired, extensively filled, and re-painted. Some parts are missing, including the quoins (the triangular elevating wedges).
The barrel exteriors are in good condition. The muzzles are blocked, so I could not see the bores.
Here are some photographs.
The lithograph on the left is of a 9″ Armstrong cannon. Centre is the battery at Queenscliffe before the present fort was built. On the right is the monitor Cerberus, with 10″ RML guns. Cerberus was scuttled as a breakwater at Half Moon Bay, Black Rock. Her guns were removed and placed nearby on the seabed, where, as far as I know, they remain.The weight refers to the barrel weight and does not include the chassis or carriage. Fort Gelibrand is at Williamstown, where there was a battery for the defence of Melbourne, consisting of 9 substantial cannons. I also visited Williamstown, and photos of the much larger guns which are still there, will appear in a later post.The Port Fairy 80pd cannons were almost certainly originally mounted on wooden carriages and slides like these, until upgraded ~1877.These carriages and chassis’ appear to be substantially original.Queen Victoria’s cypher on these guns is in good condition and exceptionally clear.
I like to think that I have very few vices outside the workshop, where there are quite a few.
But, one of the vices in which I indulge occasionally, is a good Cuban. And I make a point of indulging no more than 3 per week.
And, actually, that does add to the number of vices in my workshop, because that is where most of the Cubans (and Bolivians, and other central Americans) meet their destiny.
SWMBO does not encourage cigar smoking in the house for some reason, but I quite like the stale cigar smell in the workshop. Come to think of it, maybe that’s what is keeping the tigers outside.
To cut to the story, my son in law, James, gave me the Humidor pictured above, for Christmas. A great gift, which I greatly appreciated. Mind you, I have a sneaking suspicion that he might have had an ulterior motive, because James too enjoys an odd cigar, and he likes his cigars to be at the perfect humidity of 75% when he visits the workshop, “for a chat” or whatever.
The humidor box is very nicely made, with a Spanish Cedar internal lining. Made in Indonesia. It shuts perfectly tightly and just the size for about 50 coronas. And it has a hygrometer to measure the humidity.
But…… it comes with instructions to calibrate the hygrometer. WTF! If I buy a Mitutoyo gauge, I assume that the calibration is correct. What is this “calibration”. And then there were the instructions for calibration….
place a tablespoon of salt in a plastic dish, and add JUST ENOUGH water to make it damp.
Place the dish, and the hygrometer in a zip lock sealed bag and let them stand for 6 hours.
After that time the hygrometer should read 75%
Well that all sounded Mickey Mouse to me, so I asked my fellow model engineers at our second last meeting.
As usual, in our group of 15-20 participants, one person clearly knew ALL ABOUT humidity measurements, because he had worked in the munitions experimentation industry.
Next meeting, he brought the following hygrometers……
An electronic, high accuracy instrument.2 thermometers, one connected to a well, and one in the air. The well contains water, and the difference between the temperatures in the thermometers is read off a table, giving the humidity of the air. And this hygrometer……. see next photo for the reverse………which uses human hairs which contract when exposed to moisture, moving the indicator needle. The hairs in this instrument need replacing. Frank was looking for volunteers, but no members had enough hair to spare.
But! Do you know which method the explosives experts used?
The salt dissolved in water method!
Apparently that method is accurate to less than +/- 0.5 %.
So that is what I did. And after the hours of waiting, when the humidor hygrometer should have read 75% it actually read 65%.
There was a screwdriver slot at the back, which enabled me to adjust the calibration on the hygrometer.
The figures in the columns refer to percentage humidity at different temperatures with different dissolved salts.
Apparently the explosives scientists carried a kit which contained a selection of the above salts, and they used them to calculate the humidity of the air before conducting their experiments.
NOT MANY MODEL CANNON POSTS LATELY!
But I have been working on finishing Armstrong RML number 2.
Not much to show but I have been working on the gears, brake, and chassis……
This photo shows the brake drum on the big gear, the lever cam, and the stainless steel band bent into position, and pinched ready for silver soldering. Easy to make, but difficult to get exactly right. Too loose and the actuating handle bottoms out. Too tight, and the gear wheel refuses to rotate in reverse. So I ended up making 2 steel bands. The flaps were silver soldered. Top right, and I also made a dog clutch support bracket. Not physically necessary IMO, but consistent with the original.
I originally examined the Armstrong 80pd RML cannons at Port Fairy a year ago. Then spent 2020 making a 1:10 scale model. Now, I am completing a second model. Here is a photo of the current status of the 2nd model. And no. There will not be a third.
The components are almost all made, but I estimate that there are many hours required to finish and fit them.
But this post is about my recent 2021 holiday in Port Fairy.
I spent some hours checking and getting more measurements……….
Assisted by my very curious grand daughter “what are you doing Pop?”Who then decided to take over.
My son in law brought his drone to Port Fairy. It is a Mavic 2 Pro with a Hasselbad camera. I was sooo jealous.
And here is his footage of Battery Point. If you look carefully you can see me, my daughter, and Steve controlling the drone. This was a day after the photos above were taken, and my grand daughter was not in the video. Click on the arrow to see the 2″ video.
My daughter was interviewing me again. Amazed at the details being so similar on the real thing compared to the model. My SIL says that the Port Fairy cannons are 10:1 scale examples of my models. Unfortunately the wind noise was too excessive to post her video.
My current project is finishing the second Armstrong 80pd RML model cannon. I expect that will keep me occupied for a couple of months. But I probably wont post the steps, because it will be very similar to the posts from last year.
Yesterday, my GSMEE friend Swen Pettig asked if he could use my ring roller. The following video is a 7 minute rambling chat while he was finishing the job.
I made the ring roller quite a few years ago. It is slow, but quite controllable, and does a nice job. The 1/2 hp motor is geared down, 1:40. I have rolled steel up to 100mm wide and 10mm thick.
As you will see, Swen is making a scale model approx 1:4, of the first internal combustion car by Karl Benz.
Here, he is rolling the wheel rims from 10×10 mild steel square section rod 1.5m lengths. He made 2 front and 2 rear wheels. (needed only one front…. the car is a 3 wheeler).
Sorry about the absent chain guard. Just an oversight. I warned Swen about the possibility of inadvertent circumcision.
When visiting the Armstrong 80pd RML’s recently at Port Fairy, Portland and Warrnambool, I made sure to take photographs of any old photos which were on display. Some were very interesting.
Portland RML, not dated, but I would guess early 20th century, after decommissioning.Portland RML, probably 1880’s?1880’s Information sign at Portland batteryProbably my favourite. The cannons of the Warrnambool Battery being relocated to Flagstaff Hill 1887. On wooden carriages, and towed by a steam traction engine.The Warrnambool RML on its original wooden chassis & carriage. Adjusting the elevation with crowbars while using the sights. Traversing had been adjusted with the blocks and tackles.Pulling the lanyard to fire. There was a recoil dampener. See next photograph.At Flagstaff Hill Warrnambool there is an 80 pounder on its original teak carriage. I asked to see the recoil dampener which had been removed. 2 staff members very kindly took me into the warehouse where many unrestored items are located. This is the dampener. I guess that the bronze clamps were compressed onto a metal rod to reduce the recoil distance at firing.Externally the 64 pounder was the same as the 80 pounder. On its original teak chassis.
10 members of my family had a brief vacation in South West Victoria after Christmas. It was a nice holiday, but with three 5 year olds and an 8 year old, it was noisy.
I took the opportunity to revisit the Armstrong RML’s at Port Fairy and Warrnambool. And to visit the one at Portland for the first time.
Every time I see these cannons I learn something new about them. And I got to talk to a local historian at Port Fairy. Colonial Victoria purchased 25 or 26 of these muzzle loading rifled cannons in 1866. 10 of them are still in existence. I have now seen 5 of them. I believe that there are further barrels at Fort Queenscliff, Point Nepean, and possibly Cerberus which I have not yet seen.
“80pr” indicates that the cannons fired projectiles weighing 80 pounds. On all of these cannons the case of the elevating gears is stamped thus….
I am not sure what M2 GAR. stands for. Could it be an abbreviation of Mr WG Armstrong (later Lord Armstrong), the designer of these guns? (note 27 Jan 21. I spoke at length with Australian cannon expert Peter Webster. He said that GAR stands for “Garrison”. Not sure why, but maybe to distinguish it from naval guns.) R.M.L. will stand for “Rifled Muzzle Loader”. 80 PR will be 80 pound projectile. 6 FT PAR had me puzzled, but when I saw that the guns were designed to sit behind a 6 foot parapet I am pretty sure that will be the solution. And in a smaller font below, WD with a vertical arrow will indicate that the part has been approved by the War Department.
The Portland 80pr RML
From a distance, it looks good. The shapes in the carriage and chassis stand out with the white paint, and the assembly looks reasonably complete, except for absent winding handles and sights. Closer inspection however is disappointing. The cannon was restored in 1985 and the parts which were replaced such as the biggest gear, the elevation quadrant scale and trunnion caps, and elevation gear are significantly different from the originals on the Port Fairy and Warrnambool cannons. They appear to have been cut from mild steel in a fanciful representation of the original designs. Arc welding has been extensively used to join components. It is OK as a tourist attraction, but useless for historic study.
And instead of pointing over Portland Bay, it points at the large grain silo.
PORT FAIRY CANNONS REVISITED
Overdue for restoration works, the carriage wheels are largely crumbling into rust, and the girders have large rusted missing sections. The barrel of number 22 is elevated to a high angle which would never have been used, but is useful for firing blank charges for the entertainment of tourists, and which I enjoyed 12 months ago. Number 17 barrel rests on its parapet, at such a low angle that it too would never have used. The total lack of restoration does allow one aspect of the barrels to be visible, and that is the coil construction of the barrel segments.
Number 22Close up of the breech steel. Pitted and rusted. Can you see the spiral strips of iron which were bent and hammered as red hot strips up to 200 feet long, around a mandrel?
I measured the widths of the strips, and found that those on the narrowest part of the barrel (the chase, near the muzzle) were the narrowest at 36mm, and those of the biggest barrel diameter, the breech, were 50mm wide.
As a comparison to the previous photo of a coil constructed barrel, this similarly rusted 1861 SBML (smooth bore muzzle loader) shows no evidence of the spiral iron strips, and would have been a cast iron construction with machine bored bore.
I was also able to work out the structure of the girders on the Armstrong RML, and the reason for all of those rivets. The top and bottom pieces are T section iron, and the sides are 3/8″ (9.5mm) plate iron. There are small pieces of iron to fill the gaps at the ends, and where intermediate rivets are used in the middle sections. Using a percussion technique, taught to all medical students for diagnosing pneumonia, I could work out the locations of all of the small middle pieces.
The girder end, showing the T pieces, side panels and middle filler piece.My sketch of the construction of the girders.Another family member being introduced to the Port Fairy RML cannon, probably as a fashion accessory.
WARRNAMBOOL ARMSTRONG RML’s
These have been expertly restored, and are the most complete examples which I have seen. They were painted entirely black which makes photographs more difficult to interpret.
Whales are commonly seen in the bay. Unfortunately none on this day.
This is a close up of the projectile loading cradle. The deep groove at 6 o’clock caused me to re-examine the history of studded projectiles and non studded gas check projectiles. Apparently the studded type were used until the mid 1880’s but were discontinued when gas checks were introduced. Gas checks were effective and caused less bore erosion wear than the studded type. The groove at 6 o’clock would have accommodated the lowermost stud. The cradle would have continued to be used with the gas check projectiles.
Next post will include some interesting historical photos, and other restored cannons which were recently installed at Port Fairy.
Christmas 2020 seemed to hold particular significance. Our children, their families, grandchildren all congregated and had a superb vegetarian meal with food preparation shared. Vegetarian, because a majority of our extended family are now vegetarian. One is a vegan, and some of us are inching our way towards that aim. Even the omnivores are mostly reducing their meat intake.
We enjoyed some lovely Australian wines, with Pavarotti in the background.
This was the first time that the whole family has been together for 9 months.
Everyone had a hand in food preparation. Two Hands Shiraz 2017.Perfect weather. 25ºc. The grand-kids had a separate table outside. A very happy gathering. 3 daughters on the right. Sons in law and a family friend on the left. You know who at the end.
The grandchildren had been forbidden to get up for presents before 6am. And my son in law set their clock back an hour! So it was a leisurely start to the day. 7am.
We usually do a Kris Kringle for adult presents, but this year, we just decided to have no restrictions.
I had wondered (and to be honest, been slightly anxious) how the model Armstrong RML cannon would be received by my son in law (front) and youngest daughter (right front). Neither of them have any interest in weaponry or military history. My son in law grew up in Port Fairy where the original full size cannons are slowly rusting away. And my daughter took part in 2 casting sessions to see what casting was about. But neither had any idea that the model cannon was for them, and apart from the aluminium casting, neither had seen the cannon gradually being made.
Their reaction exceeded my most hopeful expectations. Both became teary, as did I.
The following video was made by my daughter. The daggy paper hats are part of our celebration. Totally unscripted. And I have had a few by this stage of the day.
I bought this 100 year old French vase for SWMBO for Xmas. I had no idea what its value was, but just loved the decorations, colours and shiny surface. It is quite small, and would hold only one flower if used as a specimen vase.
But….
It had no base. Was open at both ends. And had been slightly damaged from being top heavy and falling over for the previous owner on several occasions.
The damage had been professionally repaired. As you can see from the photos, the vase is quite exquisite.
The antique dealer, with whom I have dealt on many occasions, has had a tough few years. Antiques of all types had really become unfashionable. I asked how things had been in 2020, and was very surprised to hear… “Business is booming. Never been busier. Despite viewing by appointment only for most of 2020.” Which I was very happy to hear, because Moorabool Antiques, in Ryrie St Geelong, is one shop that I always enjoy browsing, and chatting to the very knowledgable staff.
Since the vase had no base, he said that it was much cheaper than if complete. It was still quite costly, but I am pretty sure that SWMBO will like it.
And……I am pretty sure that a half competent machinist could make a base for it. Paul, the Moorabool Antiques proprietor was interested. I showed him a photo of my model Armstrong cannon, and he became VERY interested. We discussed designs and materials for the base, and methods of attachment. It would have to be water tight if it will be used as a specimen vase. The attachment method would have to not affect the existing structure or decorations. I mentioned Super Glue. Paul suggested Silicone. So Silicone it will be.
I searched Google Images for similar vases, and discovered at least a dozen designs by the same artist, Alexandre Marty. It is Limoges enamel over silver foil on copper. And as you can see from the photo of the similar example with a base, the missing base was probably gilded brass or copper or bronze.
I searched my workshop for bronze/brass/copper of sufficient size, and found some copper, LG2 bronze, aluminium bronze and brass. After looking up the properties of the materials which I had to hand, I chose the aluminium bronze. As the name suggests, al-br is mainly copper, with aluminium being the second constituent. It is particularly resistant to corrosion so is commonly used in marine applications, such as propellors.
First I turned a shoulder which would loosely fit into the base of the vase. Then cut off a 10mm disk.The alu bronze turned really nicely. The hardest aspect was the tiny lip (2mm) that the lathe chuck gripped. The workpiece came free from the chuck several times. I probably should have drilled a central hole and attached a rod through the headstock of the lathe. And filled the hole when finished. (But I didn’t.)
Can you see the gold coloured rebate? That colour developed when the workpiece became hot during machining. That gold colour is a property of al-br, and is often used by jewellers. I slowed the feed-rate to avoid further heating, and got the contrast from the other bronze coloured surfaces. It will be interesting to see what happens to the colours with time. Although the vase base diameter has increased only by 10mm, it is much heavier, and should resist toppling.
The result, and the image of another M. Alexandre Marty vase which I used as a model for the base.Just to show that my life is not all gunpowder, cannons and steam.
So, the first model Armstrong 80lb RML is finished. Final photographs following. I admit that some artistic license has been taken, as directed by SWMBO, and some scale details have been modified slightly in order that it is finished in time for Xmas.
Yesterday I fished out the components of the other model cannon, the “A” version, which I am making for myself, and which will be used in model engineering exhibitions. I predict that it will take another 2-3 months to complete. I am intending that it will be more rigorously an authentic scale model, and probably less pretty and decorative than the version pictured below. But it will look interesting alongside the 24lb long gun of the Nelson era, the 32lb carronade, and the huge Ottoman 1465 bombard, all to 1:10 scale.
Here are the final photographs of the “artistic” B version.
The FIRING position. The gunpowder bag and projectile have been loaded, the gun captain has set the elevation and locked it. The dog clutch has been disengaged. (the dog clutch handle is behind the squared shaft in the above photo).After firing the recoil has pushed the carriage up the inclined chassis. The big handwheel will be used to position the carriage higher on the chassis for loading.After swabbing to douse any embers, the gunners will lift the gunpowder bag onto the loading cradle and it will be rammed into position, then 2 of them will lift the 80lb projectile onto the cradle and ram it into position. A rope quoit stops the projectile from sliding out of the barrel. The barrel is levelled, then rolled forward into the firing position, controlling the descent with the brake. Brake lever shown here. The elevation is set and locked (locking handle on the other side), ready for another firing. The rear bumpers were the final parts to be made and fitted. Just seen here.
When I make the sights for my “A” model, I will also make some for this one.
There is a name plate which was lasered by my colleague Stuart Tankard but that reveals a bit too much information to show here. Suffice to say, it names the cannon, a few basics specs, maker’s name, and year. It will be fastened to the wooden base. It also states “NEVER FIRED IN ANGER”.
Thankyou to all of my readers, many who have supplied useful advice and welcome encouragement. Particular thanks to Stuart Tankard for his lasering expertise and machine, and other technical advice. And thanks to SWMBO, who has warmed to this project as it approached completion, despite having absolutely no interest in weapons of destruction. She does have a good eye for form and colour. And mostly for putting up with my foul moods when things went wrong.
Now. It will be interesting to see if the recipients of this model actually like it.
I have machined a wooden base and I will fasten the central column of the cannon chassis to the base. The reason is that people cannot resist swivelling the cannon around on its column and the the wheels tend to mark/scratch polished surfaces. Better to mark a wooden base than a polished mantelpiece. But how to finish the surface of the base? Any polish/paint will quickly develop marks from the wheels. I have decided against making steel railway lines for this model.
I have used an Australian hardwood (mountain ash, a very hard dense wood, reclaimed from a demolished building). I am thinking that I will just oil it. The colour of the wood will darken with age, but will never be as dark as the table, which I made decades ago from Australian Iron Wood. (note, not iron bark. Iron wood. The hardest, densest wood I have ever used. And yes, I have worked with lignum vitae, and Australian red gum. The marks in the surface of the table are only in the polish. The wood is almost impossible to scratch. My kids used to dance on this table 30 years ago.)
The burn mark on the end of the base is from the belt sander. I will remove it with hand sanding before oiling.
The machined finger grips on the ends were made on my vertical mill with a steel moulding cutter intended for metal machining. It worked well.
I discussed the finish which I wanted to achieve with my resident finishes expert. SWMBO. I wanted a slightly darker, low sheen finish, which would not get scraped off with the cannon wheels.
She recommended this stuff. It is a stained, penetrating oil. Smells very chemically.
It is actually a surface repairer, rather than an overall finish but I did what I was told.
OK. That looks good. The surface will be easy to touch up if required.
1:10 Model Armstrong rifled muzzle loading 80lb cannon WILL be ready for Xmas.
Apart from minor touch-ups, the model and painting is completed.
I will take some careful photos before it goes to its final home, but here are a few snaps to show how it appears with some paint and lacquer.
Oops. Forgot the big handwheel.The gears, brake and dog clutch all work well.and a few more chassis bolts to insert.I extended the recoil piston rod to allow full travel of the carriage on the chassis. The join is smooth.
So, was SWMBO correct about not painting the chassis? I like the look of this finish scheme, but now have to decide what to do in that regard with the “A” model, which was put aside while I finished this one.
p.s. I weighed the model, because I was curious. The full size original barrel weighed 81.5cwt/4.1 tons plus the carriage/chassis, about 5 tons/5080kg total. The 1:10 scale model should weigh 0.1 x 0.1 x 0.1 or 1/1000th of that which would be 5kg/11lbs. It actually weighs a tad under 10kg/22lbs which is almost exactly double the predicted. It is a bit of a lump to carry around and I do NOT know where the extra weight came from. Or maybe my mathematical assumptions are incorrect.
(note added 1 March 2021. See the post added 1 March 2021. The total weight of the gun barrel, carriage, and slide – which I have been calling the chassis, was close to 10 tons! So my assumption that the model should weigh 1/1000th of the original was very close to correct!)
The accuracy of cannons was dramatically improved in the 19th century with several developments.
The bore was machined rather than just cast, as result of the invention by Wilkinson of a powered boring machine. Incidentally, this process was also adopted by Trevithick in making steam engine cylinders, significantly improving the efficiency of steam engines.
The adoption of sights, calibrated for distance, and movement of the target, instead of just eye balling along the barrel.
Changing from round iron balls to cylindrical projectiles, with a pointy front and slightly rounded rear.
Rifling the barrel bore, causing the projectile to rotate.
Standardising the weight and granularity of the blackpowder, making shots more repeatable.
Increasing the power of gunpowder by increasing the size of the “corns” which sped up the rate of combustion. This permitted flatter, more accurate trajectories.
Improvements and calibration of degrees of barrel angulation.
Increased research and knowledge of the science of ballistics.
Increased training and professionalisation of gun crews.
The Armstrong 80lb rifled muzzle loader had a projectile which weighed, you guessed it, 80lb (36kg). A bit later cannons were categorised by the weight of the barrel. e.g., the 80lb Armstrong would have been named a 4 ton cannon. The gunpowder was standardised at 20lb per firing. The gunpowder filled silk bag, then the 80lb projectile were manually lifted onto the loader cradle, then ram rodded into position. Later, bigger cannons, needed a small crane to do the lifting, but in 1866, the 25 Armstrong 80lb cannons which were made specially for Victoria and South Australia, and were the most advanced cannons made at that time, required strong gunners to do the lifting and ramming.
My model Armstrong cannon is basically a display, rather than a working (firing) model. So, for the display, I have made some projectiles, and fake gunpowder bags. I was fortunate to find some old diagrams of both.
As you can see, for an 80lb RML cannon, the projectile is 15″ / 380mm long, and just under 6.3″ diameter. The barrel bore is 6.3″ diameter, and to cope with heat expansion the projectile must have some “windage” (a gap) to avoid jamming. The 1866 projectile has a pointy end, and a rounded rear, which is relatively aerodynamic, and similar to the form used in many modern guns.
Attached to the rear of the projectile is a (dark shaded) copper disk, which expands into the rifling grooves after firing, and further reduces the windage, and causes the projectile to rotate. The copper disk separates from the projectile after they leave the barrel, and it falls to earth. The best examples of the copper “gas checks” have been retrieved from the sea, in front of shore batteries where these cannons were located.
Before gas checks were introduced, the projectiles had copper studs attached to their exterior. The studs fitted into the rifling grooves. The studs were effective at causing the projectile to spin, but they caused rapid wear of the cannon barrel, excessive drag and lower muzzle velocity of the projectile, and were slower to load. The 25 Victorian Armstrong 80lb RML cannons were designed so that studded projectiles could NOT be used. (n.b. note added 7 Jan 2021… that last sentence is incorrect. The 80lb RML’s would have used studded projectiles until mid 1880’s, and then changed to gas check projectiles. instructions were issued then that studded projectiles should not be used.)
The following drawing shows a silk bag, containing the gunpowder. It also shows the central wooden rod which prevented the bag from bursting during ramming. This powder charge is for a 10″ RML, so it is bigger and heavier than the one for the Armstrong 6.3″ RML, but the design is essentially the same.
After loading and aiming, the gunner would perforate the silk bag with a long spike, then insert a quill or later a copper tube, full of fine gunpowder which extended through the vent from the touch hole to the perforated silk bag. Royal Gun Factory experiments showed that the best firings occurred if the silk bag was perforated about half way along the cylindrical bag, so the vent and touch hole were located at that point.
Some scaled projectiles in mild steel and copper gas checks. Some more shaping required for the gas checks, then they will be attached with gunmetal (bronze) pins to the projectiles. The 1866 projectiles had a cast iron case, were packed with explosive, and a fuze. The book is a reprint of an 1897 publication. It has been consulted many times, as you can see from the workshop stains.
The method of igniting the gunpowder will be described in a future post.
Today is the 40th successive day that Victoria has had NO new covid cases. It seems worth the prolongued horrendous lockdowns experienced earlier this year. Full marks to our public health officials, health workers in hospitals, and politicians. (yes, even the politicians. They had a steep learning curve, and made mistakes, but I believe that they tried very hard to make correct decisions.)
The result is that we had our first face to face GSMEE meeting since January. And with Christmas just a couple of weeks away, it was our annual Xmas BBQ. I hasten to add that the vegetarians in our group were well catered, as well as the omnivores.
There were 5 entries in the club competition for making a small engine, and it was convincingly won by Neil McMeekin. Neil’s engine was beautifully finished and it ran smoothly without any mechanical noises. Frank Mullins 2 entries both ran well, and he was awarded the second prize.
Judging the competition engines. checking the finish, and running on compressed air. To the right is Rudi vanderelst’s “Britannia” which is taking shape with Rudi’s expert attention and knowledge. Rudi was a marine engineer, originally on steam ships, and what he does not know about triple expansion engines ………… Hanging on the staircase rail is a one meter micrometer, brought in by Chris Tywonek, our resident gun expert.
The “models on the table” included my still not finished scale model Armstrong cannon. It is now painted, and clear lacquered.
In the foreground is Stuart Tankard’s model of an Otto D2 gas engine, originally made in 1895. As usual with Stuart’s work it is perfection in motion. Not quite finished, but when it is, I will post a more detailed description and photos.
To the right of that is a bronze cannon cypher off an Ottoman cannon which was captured in Mesopotamia in WW1. The wooden mounting plaque is from a British Spitfire propellor. Owned by Laurie Braybrook, at 95 our most senior member, and raconteur extraordinaire. Laurie fought in WW2 in the Pacific islands, and he has many wonderful stories.
Ottoman cannon cypher. I love the Arabic (I think) calligraphy, and the symbol of the horn of plenty. It is quite a thick and heavy object.
Behind Stuart’s Otto is a Bolton 7 horizontal mill engine, made by Neil Ellis. Again, not quite finished, but it is displaying an incredibly high standard of machining and finish. This is Neil’s FIRST model engine. Again, I will feature it in a future post with more details. Neil comes from a boatbuilding occupation, so he is no stranger to precision and machining, but this level of model engineering in a metal working beginner is amazing.
Then my cannon, which is probably suffering from some overexposure in this blog, so I will add just one more photo, since it has now been painted and laquered.
Still a few pieces to be added to the Armstrong. Our member Neville, who used to fire the original full size Armstrong at Port Fairy, saw the model for the first time today, and he was interested to see the hand wheels and other bits, which are missing from the Port Fairy original. I think that he was a bit disgusted that I have not made a vent/touch hole.
At the rear are Swen Pettig’s “Minnie” 1″ traction engine which is looking great, and his therapeutic Grasshopper Beam engine. I say “therapeutic”, because the Grasshopper is Swen’s escape from working on the Minnie. His size 13 hands have been a serious handicap to assembling the Minnie, and I gather that there has been much stress and frustration. (But he is talking about making a triple expansion engine like mine, so he is clearly a glutton for punishment. The barring slots in the flywheel of the grasshopper are an interesting feature, and I hope to get post from talking to Swen about those.
I think that everyone was excited and delighted to be face to face again, and looking forward to normal GSMEE meetings in 2021. Zooming has been a good “stop gap” but I think we are all ready to resume normality. Hopefully with no further lock downs.
First, I have decided to NOT rivet the final joins of the chassis. Instead I am using dome head stainless steel bolts and nuts. The main reason is that the other end of the rivets are in impossibly small (for me) cavities and spaces, and I could predict that the final riveting result would be horrible. Even using threaded rivets would be incredibly difficult. This decision does cause me to reflect on the 1866 cannon builders who managed such perfect results with red hot rivets in confined spaces, and again, to be awed.
As you can see, the bolt heads are same shape and size as the 2mm copper rivets. My intention was to paint the rivets and the bolts (after filling the hex holes) and then they would be virtually indistinguishable. However, that plan was blown out of the water by SWMBO. (read on).The copper rivets and stainless bolts. Not kosher. But interesting?
To divert, back to the painting.
Question. When painting a model, is it best to assemble the whole model then paint, or to completely disassemble every part, paint the parts then reassemble?
1. Disassemble and paint the parts then reassemble. This results in complete paint coverage of all parts. It results in clean separation of different coloured parts. Mistakes involve limited areas and are easier to correct. However, the thickness of the paint can alter carefully machined tolerances. And surfaces can be painted which were intended to be unpainted.
2. Assemble the entire model, then paint. This can make some recesses, corners and hidden areas difficult to access. But the appearance of the entire model can be assessed as the painting progresses, and major mistakes in colour choice can be corrected. The painting process does not alter dimensions or fitting together of components. But paint edges and joins can be difficult to keep neat and straight, particularly in my inexpert hands.
3. (Obviously what I chose to do). Partial assembly, into modules, then paint the modules separately. This has the advantages of both 1 and 2. The modules can be stacked together to periodically assess the results. The modules are smaller than the complete model, and easier to handle. Difficult decisions regarding colour, or whether to paint at all, can be deferred until the easier parts are painted, and some idea of appearance ascertained progressively.
So that is what I am doing. I have painted the bottom part of the chassis, and the carriage. Etch primer at this time, but already firming up ideas about final colour. And my colour and design expert advisor (SWMBO) has had some input into this decision.
These are the main modules, 4 of them. The barrel assembly is stainless steel and it will not be painted. At the rear are the carriage and bottom part of the chassis, which have been primed. The main chassis beams containing the movement gears are unpainted. The carriage looks naked without its bling.
At this stage, I asked for advice from SWMBO. She has suggested that the primed modules should be painted satin black, which should contrast nicely with the brass/bronze components. Avoiding gloss will minimise the finishing defects. Some filling of defects will be required in any case. The black colour will be tested on the carriage, and if it looks OK, the chassis subframe will receive the same colour.
SWMBO’s most interesting suggestion is to NOT paint the main chassis beams at all! Well, a clear lacquer will be required to prevent rust.
But. What about disguising the copper rivets/stainless bolts?
SWMBO: “they look interesting. Leave them.”
Me: “but, but, but, they do not look authentic.”
SWMBO: “This has to look like a work of art, otherwise it will be just a boring dust gatherer.”
After my crap riveting of the carriage, I could have ripped them all out and started again. Or, I could slap on a coat of paint, and take another look.
Well, that’s what I did.
Well, actually, before that I telephoned my riveting expert about my rivet problems, and he gave me some further advice……
Put a G cramp on the compressor hose to restrict the air flow
Polish the ends of the snaps, and round the edges slightly
Check that the shape of the snaps mirrors the shape of the rivet heads. It didn’t. I had thought that the dome rivets had hemispherical heads, but on closer inspection, they were flatter than a hemisphere. So I made some new snaps, and took great care to make sure that the rivet heads fitted more precisely into them.
Be more careful to keep the snaps perpendicular to the surface.
I did replace the worst rivets, and I was much happier with the results.
Then some paint. But first I gave the carriage a thorough wash in detergent to remove any trace of machining oil.
Then, using a pressurised can of etch primer, used my spray booth (a cardboard carton open at one side) to give it a coat.
I quite like that colour. The blue splog is some marking paint. The etch primer refused to stick to the marking paint. Next time I will give the parts a wipe with acetone before painting.
And, with a bit of paint, the carriage doesn’t look half bad?
Even the crappy rivets do not stand out too badly.
Of course, some areas showed up as needing some filler…..
Some time and effort required in some areas to fill defects and divots before the next coat of paint.
I quite like that colour. Maybe with just a touch more blue in it.
The cannon carriage, partly disassembled, ready for final riveting.
I am no expert at riveting, but I have had some good advice from an expert. He has had years of experience in the aircraft industry. Prior to this cannon project I would have inserted fewer than a dozen rivets. You cannot beat experience. And knowledge.
As you look at these photos, and grimace, bear my inexperience in mind. Actually, my results improved as the day wore on.
An eye bolt goes in the X hole.Note the use of nuts on the rivets where access was difficult.I give myself 5/10
I learned a few lessons as a result of this session of riveting.
Riveting is a manual and knowledge based skill, which must be studied and practiced.
Items which are riveted change their dimensions. Components which fitted perfectly when machined and bolted together develop gaps and warps after riveting. Not surprising, considering the hammering of relatively unsupported pieces.
The tools must be perfectly designed for the job. The snaps must be the correct shape and size for the rivets.
Rivets from different manufacturers differ in dimensions, even when supposedly the same.
Soft components like aluminium can deform and break when riveted.
Retired gynaecologists should not rivet. Stick to nuts and bolts.
I am hoping that the bruises and cracks and deformations which I have caused with the riveting will be camouflaged by the paint job.
Surprisingly, the carriage still sits flat on a surface plate. And the barrel sits squarely in the trunnions.
A few more photos of the model Armstrong RML cannon. Close ups which are useful to me, because they show up defects in the finish which need attention before painting.
Makers mark (mine) to be added to the recoil tube cap. And rubber washer to the bumpers.Screws and bolts to be replaced with rivetsMetal polishing required for the muzzleOil holes for the shaft bearings, and replace the wonky rivetsFile and finish the trunnion cap keysfinishing and polishing the loader cradle.ditto more finishing.Attach the left side buffers. And make chassis wheel axles. Those M5 hex screws are wrong.Distance hides a multitude of faults
I have commenced the teardown of the model Armstrong cannon. But first I took some photographs, just in case the paint job is not the best. To explain, I do not have a great history of good paint jobs. SWMBO bans me from painting around the house (that is NOT a loss, believe me) because of runs, brush hairs in the paint, paint applied too thickly etc etc.
So here are the photos….taken with my iphone. Just to reiterate, this model cannon cannot be fired. It has no touch hole/vent.
In the firing position.
After the teardown I will complete the insertion of rivets, replacing many of the 8BA screws with rivets.
After firing, with the barrel depressed to 17º, after swabbing to remove persisting embers, ready for the 20lb of gunpowder in a silk bag, with a wooden rod in the middle to prevent the bag from collapsing while being rammed. Then the 80lb projectile with “plate like” copper gas check (to engage with the rifling) is lifted onto the loading cradle and pushed into the barrel with a wooden ram rod. The projectile had a rope quoit around the pointy end to jam it into the firing position, and stop it from inadvertently falling out while the carriage is rolled down to the firing position.
The firing rate for these 80lb cannons, with a trained crew, was about 1 round every 1.5 minutes.
There should be an OH&S sign saying, “best not to stand here during firing”.Wooden side planks for the gun crew, and a short shelf near the front to rest the projectiles before loading, yet to be made.
So, wish me happy painting. Still haven’t finally decided on colours. But probably black for the interiors, silver for wheel assemblies, wheels barrel gears and brass components unpainted. Maybe a light grey-blue for the exterior of the carriage and the chassis.
Today the gunners’ platform at the rear of the chassis was completed and fitted. It has vertical handles at each side, presumably for the gunners to steady themselves, while aiming the cannon.
The platform, ready to be attached to the chassis. The wood here is Australian Jarrah. The handles are stainless steel, discoloured from silver soldering them to the side brackets. They will eventually be painted. ps. a day later I decided that the fasteners were too big, so I have replaced them with something more appropriate. Pics later.The platform in position. This photo shows up my first efforts at riveting. Some of those rivets will be replaced when everything is disassembled prior to painting. Those brass nuts holding the wooden boards are too big and will be replaced also.
So, just 2 more parts to be made for this model cannon. Those are the sights.
The information which I have to base the sights on is a bit sketchy. But I do have photos showing these cylindrical holes in the Port Fairy cannons….
The sights are placed in the holes in the right hand trunnion shoulder, and in the breech.
After extensive searching I found several books which were published in the 19th century. This is the best diagram which I found of the rear sight. It is calibrated vertically up to 3600 yards, and there are lateral adjustments to take into account speed of movement of the enemy. The sight is angled at 2+º to the left to compensate for the rifling, which causes the projectile to deviate to the right. The front sight is located in a relatively shallow cylindrical hole. The front sight is a fairly simple point.
Not a great photo of the platform at the rear of the Armstrong 80lb RML at Portland Victoria. But, this is what I started modelling today.This is the Port Fairy cannon, which is missing the woodwork, but shows the brackets.These are the brackets which I fabricated for the 1:10 model. I did make some small design changes to make the model. I think that my changes are an improvement on the original, using existing fasteners. The wooden planks and vertical handles are yet to be added.
The central angle brackets are machined from some RSS.
75x25x2mm RSSSawed and machined to size. The bent steel is true to the original Port Fairy cannon.
You might also notice that the eye bolts have been added.
The bracket is now bolted to the chassis. The arm is stainless steel, and the top bracket is silver soldered to the arm. The loader cradle is bolted to the top bracket, the angle being determined with a neat fitting rod inside the bore. The rod looks interesting, no? I will turn up a projectile to sit there.
Then I fitted the bracket which restrains the movements of the elevation gear lock-release…
This is the “locked” position. The handle drops into a recess. The bracket looks a little rough in this magnified view. A bit more filing and sanding required. A simple curved piece encloses the handle. I will make and fit that tomorrow.
So those are the last major parts to be fitted to the cannon. Oops. I forgot. I need to make the aiming sights, and bore the holes in the barrel to hold them. None of the cannons which I have inspected have exisiting sights, presumably stolen-souvenired, but some 19th century publications have good diagrams which I will be able use to make scaled versions.
I will add a rear wooden platform, and the eye bolts.
Then a complete teardown, painting some parts, polishing others.
The investment plaster is is what the mold is made from when parts are cast in bronze and aluminium.
It is incredibly fine dust until mixed with water, and these need to be in precisely measured weights.
The mixture is poured into the casting cylinder in which the parts are attached to a wax or PLA “tree”. (see yesterday’s post for a photo of a tree).
After casting, much of the investment plaster is blown out of the cylinder when the still hot cylinder and its contents are plunged into cold water. The steam which forms acts like a steam cleaner.
But the parts are still covered with a tenacious layer of investment plaster. More can be scraped off with a screwdriver, wire brush, pressure hose etc. etc. but there remains a lot of plaster in the nooks and crannies, joins and holes.
And it is a fair pain to get it all out.
Yesterday’s castings looked like this after I had sawed the 34 pieces off the trees.
and after more sawing and use of a thin disk abrasive wheel…
there is still investment in the grooves and crevices.
Then most of the unwanted bronze branches were machined and sanded off…
still the investment powder clings on….then the investment powder all disappeared!
It happened serendipitously. I placed the parts in a gemstone tumbler with sharp stainless steel shot, to take off the sharp edges. And hallelujah! The remnants of the investment powder were also removed. The curved arms in the photo are stainless steel and brass, bent around a mandrel. I have not yet decided which to use.
In future I will use the gemstone tumbler at an earlier stage, to get rid of the investment as soon as possible.
And here is another stage of the pruning of the trees…..
I wonder if holding the angle grinder in a vise, and holding the trigger with a spring clip, will void the warranty?
It was a bit too warm for casting bronze today. 33ºc/91.4f. But I went ahead. It was sweaty.
I had installed a new thermocouple in the potters oven and it performed flawlessly. Fumes from burning out the PLA and wax from the mold had caused the older thermocouple to behave erratically, but the new stainless steel type was unaffected.
And, as I displayed yesterday, I had made a very ambitious tree with 32 parts to be cast, and a second tree with 2 largish parts.
No vents. No vacuuming of the melt. Just a straight pour.
A few minutes after the pour, the bronze is still at a beautiful fluorescent red heat.The cast 2 trees. NO bubbles (I painted the PLA trees with a slurry of investment before the investment pour). All parts look perfect, except for a tiny area of moth eaten edge on one of the parts in the top tree. Too small to show up, and quite repairable.The other side. Not much surface oxidation (phosphor copper used).
So, a very successful pour. Some careful hand sawing required to cut off the parts.
This casting tree has 30 parts. That is a record for me. Admittedly, most of the parts are quite small.
There are 20 eye bolts, 2 cannon loader brackets, 2 cannon loader cradles, and 2 ends of loader arms. Oh, and 3 bevel gear locking lever handle guides. And one extra eye bolt to make 30.
It will be interesting to see how many of these parts are useable.
Note, that the tree has a bifurcation. The parts are so small that I decided to split the flow of molten bronze into 2 trunks.
But, I joined the 2 trunks at the other end, just in case.
Pour tomorrow.
Then I decided to add another mould cylinder. I am making some more cannon chassis wheel brackets, in bronze, after improving the design.
GSMEE meeting tomorrow. But, I will be casting bronze. I might have a few minutes to join in the meeting.
Some parts on my model Armstrong cannon could not be made until measurements were checked on the assembled model.
The projectile loader was one such group of parts.
The 80lb projectile obviously sits on the cradle. The carriage is at the top end of the chassis, with the barrel angled down by 17º. The arm with the cradle swings around and meets up fairly precisely with the muzzle of the barrel. I am not sure if the projectile is placed on the cradle before or after it swings around. (does anyone know?)
I had these photos, and a few measurements of the loader assembly from the Port Fairy cannons, so I drew them up in 3D.
The components of the loader are fairly simple, and can be machined rather than cast. But I printed the components in PLA so I could test the design before I started to cut metal.
3 components. The bracket bolts to the chassis, the curved arm, and the cradle.
But, when I positioned the PLA assembly on the cannon, it was clearly incorrect. It did not line up with the muzzle of the barrel.
The only way that I could make the cradle line up with the barrel was to lift the arm out of its bracket by 13mm! I am glad that I did not waste time and material making a metal version to these dimensions! Not sure how this error crept in. But I will redraw the arm with an extra 13mm height.
I have not yet decided whether to machine the parts or cast them in bronze. Both processes are a lot of fun. I will reprint the curved arm in either case.
Well, actually, it is a 1:10 scale model of a 5 ton cannon. The model weighs around 5-10kg at a guess.
The brake is to control the descent of the barrel/ carriage down the 4º slope of the 5 meter long chassis.
On the original, the brake was a steel band on a steel drum which was attached to the big gear.
The drum is approx 600mm/2′ diameter.
This is how it appears on the scale model..
From the other direction. The stainless steel band winds around the drum, and is attached to a small lever which is operated through the shaft by a much larger lever on the outside of the chassis.
I was a bit apprehensive about this job. The lever is very close to 2 gears. the steel belt has to be properly tensioned, because the degree of movement of the control lever is quite restricted. And the width of the band has to be slightly less than the 5mm groove on the drum.
But, I found these…..
Stainless steel cable/plumbing ties. 4.75mm width, and in various lengths. And quite inexpensive.The cable ties are sharp and springy. Feeding them into position was tricky. But after bending them around the pins on the shaft I was reasonably confident about silver soldering them with a loop at each end. The soldering was straight forward. Stainless steel silver solders well.The handle is almost 1 meter long. 96mm brass on the model. It will be pinned to the shaft.I will adjust the shaft length in the next workshop session.
So, for once, my apprehension was not warranted. The job was fiddly, but no major mistakes!
WTF! I thought that this site was about model engineering, metal working etc.
Well. I just need to say that typists correction fluid is an essential tool in my workshop.
Not for typing, I hasten to add. But for silver soldering….
Today I needed to silver solder an extra 1mm thick disk to a tiny part, which already had 2 silver soldered joins. I had spent an entire workshop session designing and making the part, and I did not want it to fall apart when I added an extra component. Which I admit, was an afterthought.
And the central hole in the extra disk HAD to line up precisely with the threaded hole in the previously made part.
I had been advised by another GSMEE member that a metal surface painted with typists correction fluid WILL NOT accept silver solder. I have tried this method once before and it works. This is another demonstration.
In front of the correction fluid is the part, with the extra 1mm disk, silver soldered with the 2mm screw holding the parts together. And after soldering, the screw came out. It was not soldered into the assembly because it was coated with the correction fluid.So annoying. WordPress used to enable rotating images. Not now. So these are the components to be silver soldered. Fluxed. And parts which I do NOT want soldered are coated in the correction fluid.The work rests on brass blocks to function as heat sinks, to protect the existing soldered joins. This shot shows the workpiece after soldering. Has the correction fluid worked? Well, you have already seen the evidence. Amazingly, it does work.
This handle locks the elevation gears into position after the cannon barrel elevation has been set. Several more hours were required to file a central tapered ridge into the added material, and a corresponding groove where it rests. It all worked out OK.
Typists Correction Fluid. I hope that it never disappears from OfficeWorks.
Thanks again Frank Marrian GSMEE, and jimmymouse, for this great tip.
Attached the recoil tube yesterday. But I cheated. It is a gas strut.
The recoil tube from the front. On the original Armstrong RML’s it was filled with thick “Rangoon Oil”.
But, it is SO close to the dimensions that I required, that I decided.. what the hell. It is 18mm diameter (17.5mm required), and 200mm long (198mm required).
I degassed the strut by drilling a 1mm hole, and the gas came out under considerable pressure. I had to do that, because the strut was too strong for the cannon. Even degassed, the strut has enough shock absorbing action to be useful and realistic. I made some brass brackets and a cap, for visual consistency.
Today I made the lever which locks the elevation gears.
Not much to show for an entire day in the workshop, but it did involve a lot of planning, a bit of CNC cutting, and silver soldering. Still some small details to add.The Port Fairy original. Some bits are missing.
Yep. To make my models I use a computer for drawing, making lists, ordering fasteners and materials and tools on Ebay and from suppliers, driving CNC 3D printer, driving CNC machining tools. And laser marking parts. I also do a lot of traditional machining, hand filing and sanding.
This is 2mm thick brass sheet. I asked Stuart T, who has a 30w fibre laser, to mark the elevation scale protractor for my Armstrong 1:10 RML cannon. Not sure of the outcome, I supplied some blanks (LHS), and cut out parts (RHS), and a CAD drawing of the part and the text.
The cannon barrel will elevate to 30º, and depress to 5º for firing, although in practice deviations from a degree or two from 0º were rare. Plus there is an extra mark for 17º depression, which was the reloading angle. The numbers which the laser marked are only 0.6mm high. Hard to see with the naked eye. But in scale.
Lasering the tiny marks and numbers took 2 seconds per pass. That is, 2 seconds to make all of the marks and all of the numbers. After some experimenting, we settled on 50 passes. Which was still less than 2 minutes per part.
Click on the following frame to see the video…
How fantastic is that????
So quick, precise and clear. Yep. I am quite happy to employ any new technology which is available to me.
Then today I made the fittings to secure the recoil tube, and drilled and tapped the 8BA fasteners.
The carriage, chassis and bling is really coming together. Just a few more bits to make and install, then the final riveting and painting. Ready, I hope, for Xmas.
The recoil tube is a commercially available gas strut. It was so close to my 1:10 scale dimensions that I decided to cheat, and use it.
I drilled a 1mm hole in the gas tube to release the gas and oil, turned and re-threaded the front end of the piston rod to 6mm, and made the brass supports and end cap. I released the gas because it was too stiff for the model. Even without the compressed gas the strut has some “shock absorbing” activity, and I am quite happy with the decision.
I suspect that this post will not be of much interest.
But the parts represent 2 whole days in the workshop, so I am writing these notes for my own diarising more than your entertainment.
The chassis of the model Armstrong RML cannon has a cross bar, which is bolted to the longitudinal bar, and is attached to the side girders with some small, shaped clamps.
On the original Port Fairy cannon. There is a 4º difference between the girders and the central bar.
The crossbar is under the big gear. Still some shaping required to improve the appearance. When I have finished the gaps will disappear. The difference between the original and the model cross bar relates to pragmatics of shaping miniatures. Compromises inevitable. And if you noticed, the fasteners on the left are BA8, and 2mm cap screws on the right. I need to buy more BA8’s.
The cross bar doesn’t look much, but it has 4 bends and a twist. The space was too tight for me to measure the angles, so I bent the cold bar by estimating the degrees by eye. Same with the twist, except that the twist had to be confined to the section not attached to the girder or the central longitudinal bar. So I heated that to red heat with oxypropane. The twist was 4º. But I eye balled that too.
8BA bolts x6 in a hex pattern join the cross bar to the longitudinal bar.
The clamps required some planning. I considered machining them from solid bar, but work-holding was going to be problematic.
So I silver soldered 2 strips together, cut off the pieces, then sanded, filed, and manually bent the angles.
The silver soldered join overlaps by only 2mm, but it survived some aggressive bending. 100mm long. The parts were sawn off, then further sanding, filing, and hole drilling. Workshop dirty fingers with swollen arthritic joints.
p.s. Another day later, more of the same…
This is the underside of the model Armstrong cannon carriage. I have bolted on the 4 cast bronze fittings which hold the carriage onto the chassis. Later those fittings will have wooden/steel disks sandwiched and bolted onto them to become bumpers at the extremes of travel of the carriage on the chassis. All of the cap screws will be replaced later by hex head BA bolts.this is a view of the underside of the chassis, with the carriage secured above. An unusual view.
I would prefer to use 2mm metric bolts rather than 8BA, which is a similar diameter and pitch, but unfortunately I have been unable to find a supplier of 2mm bolts with hex heads. BA bolts are several times more expensive per piece than metric, and it adds up when using hundreds per cannon.
2 days in the workshop, and not much to show…. just one photo.
Yes, the trolley wheel axles need to be shortened. Next time the carriage is disassembled. The recoil tube is just sitting there, for effect.
The curved brass bar is a protractor for measuring degrees of elevation of the barrel. I used High School trigonometry to work out the distance from the pivot point at the centre of the trunnion, to the pivot centre at the fitting under the barrel.
Then cut out the shape from 2mm brass with the CNC mill. That was the easy bit. Although it did takes 3 goes to get the radius of the curve correct.
Today, although feeling depressed after the Cats loss last night, I made the cross bar with the rectangular cutout, then spent a couple of hours bolting it into place. It all works smoothly. The rectangular cutout is 2.2mm wide and 7mm long. I chain drilled with a 2mm carbide milling bit, then milled the slot sides, then filed the corners square. It is stainless steel. Slow work.
I have not worked out how to engrave the protractor marks, which are at 0.25º intervals for elevation, and whole degrees for depression. I could ask Stuart T to engrave it for me. The design and actual lasering would be straight forward, and I am sure that Stuart would help if requested. The problem would be to align the part on the laser machine, so that the engraving occurred exactly at the correct location. Actually, as I type this, I think that I have the solution. Watch this space.
I need to make a pointer next, and to determine the 0º position. The carriage sits on the chassis which is at a 4º slope. Not rocket science, or brain surgery. Just need to get it right!
I made a 1:10 model of this Ottoman bombard a few years ago. This one was made in 1465, and is thought to be a copy of the bombards which brought down the walls of Constantinople in 1453. This one resides in the Royal Armories Museum at Portsmouth, UK, and I photographed and measured it in 2019. It has a bore of over 600mm, and fired stone balls of over 350kg.
Last used in anger against the Brits in 1807, where it and others like it, were instrumental in preventing a British fleet from invading Istanbul (renamed from Constantinople). How many weapons have an active life of ~350 years?
…and the model turned out well. 550mm long, but, it is made of wood.
So I am contemplating making a model at the same 1:10 scale, like the original, in BRONZE. It will have the same shape and size, but will look like and feel like BRONZE.
I still have my original measurements and drawings of the model. So my plan is to print the cannon parts in PLA, taking into account my extra information from the 2019 visit, then to cast it in BRONZE.
I had planned to stop this blog after finishing the Armstrong RML, but maybe , if there is enough interest, I will keep it going for the next project. You will need to let me know if this project will be of interest. Because lately, comments and likes are few, and numbers have been discouraging. And the renewal date for WordPress is approaching. I get it that people prefer videos, but that is not my style. If this written plus photographs style is not wanted then I will not persist.
The part measures 20x12x7mm. And it has some tiny details.
Not quite finished here. Still needs a shaft hole drilled and reamed, and the top holes to be threaded.
The design is simply and quickly drawn on V-Carve. A rectangle with rounded corners for the base, and a rectangle with 2 arcs on each corner of the column. Circles added for fastener holes.
This is where it ended up….
The part is a bracket for the shaft. It locates the shaft in 3 dimensions, so the height of hole above its base is exact.
There are many ways to approach the machining of the part, and this is the technique which I used……
The part is machined in the end of a piece of material which can be held in a vice for milling, and later held in a lathe chuck for parting off. The hole for the shaft was made after parting off. The parallel end faces permitted it to be held in a vice. The shaft hole could also have been made by holding the brass rod in a vice or chuck before parting.Not quite finished. When the bracket comes off next time, it will spend some time in the gemstone tumbler to take off the sharp edges and improve the surface finish.
The control wheel for the elevating gears was found in my rejects box. It was made for the triple expansion engine. It looks pretty good? Cant remember why I rejected it for the triple. Maybe my standards are lower these days.
There are not many photos of these cannons on the net, and none of them show this wheel. Or was it a simple handle? The shaft has a squared end for a wheel/handle of some sort. So this wheel is my best guess as to what would have or could have been used. Virtually all of the cannons remaining of this type have had the small parts removed/souvenired/stolen which is sad. Some old photographs of bigger Armstrong RML’s show wheels of this type, so I feel justified in making this design assumption.
P.S. And after making that comment above, I rediscovered this photo a few days later. I think that it is the Armstrong RML at Portland, Victoria. Note the hand-wheel at the front, which will be for barrel elevation. This is a different setup from the gun which I am modelling, with the gears within the carriage, but the hand-wheel is similar to what I came up with.
Another design consideration. SWMBO likes the cannon without the chassis, as in the above photo.
But this is how it looks on the chassis.
…and there are many hours of effort in making the chassis, and movement gears/brake/big wheel/riveting etc. and still more to be added, such as the projectile loader, gunner platforms, etc.
The gun and its carriage have brackets which make separation from the chassis very difficult/almost impossible. So I am considering a design modification which would permit a choice of with or without chassis. What do you think?
(please note. this is a MODEL cannon, has no touch-hole/vent and is therefore not capable of being fired.)
Firstly the right hand carriage side was removed from the carriage.
This is a side of the model Armstrong RML carriage.
I turned a disk with a small hole to locate one arm of the dividers at the centre of the trunnion, and positioned the quadrant gear. Then super glued it, and its pinion, into position. Marked the locations. The super glue will be removed later.
Then drilled and reamed the pinion hole.The location of the barrel fitting was determined after reassembly of the carriage, with the quadrant gear still glued into position. Very tentatively drilled and tapped the holes for the bronze fitting into the barrel. That cap screw will be replaced by a shop made countersunk screw.
The bevel gear case was located through the pinion gear hole, and keeping the control handle shaft level. The case was drilled and bolted into position. The control handle shaft will be replaced by one of smaller diameter, in keeping with the 1:10 scale.
starting to look like the real thing….That cap screw is temporary.
A couple of days in the workshop working out how to position those parts and drilling, tapping, and reaming. The other cannon will take less time.
This photo is the original Port Fairy cannon, and the 3D printed 1:10 model size copy. The original is ferrous and the guide is bronze or gunmetal. I decided to make my scale model versions from brass, for ease of construction, and to avoid rusting because these parts will not be painted. I did not have a piece of brass big enough and thick enough to cut a 360º disk. It would have been 182mm diameter and 2.5mm thick. So, I made this fixture, and attached an aluminium plate.Bolted on some bits of brass bar the correct thickness, using holes outside the gear, plus one which will be incorporated into the gear.Then cut the teeth, using my CNC rotary table.Then used the same fixture held in the milling vice, and cut the interior contour, and a rebate.The ends still need to be shaped. Showing the curved guides, rebates, and the bronze castings which secure the gears to the barrels
Making brass fittings is always a nice and enjoyable part of a modelling job. Making “bling” as my GSMEE friend John B characterises it.
I had 3D printed another tree with 4 cannon parts. Brackets. The complete tree fitted into a steel flask 100mm diameter and 120mm high. So I repeated the steps of the last successful pour, and painted the tree with investment slurry, mixed the main investment, degassed it, poured it, and degassed the entire flask, investment and all. That method had worked well before, so I repeated it.
But I was a bit concerned because the investment was only a few mm thick at the bottom of the flask. Would it hold up? Read on.
So then commenced the drying, burnout, and baking cycles in the potters oven. Normally it is about an 8 hour process, and I did not get to start until 12 midday. So I was in for a long day.
But then the oven started to play up. It would suddenly switch off. The temperature gauge would swing wildly. And would not heat above 400ºc and it needed to reach 710ºc.
I did not know the source of the problem. Thermostat? Wiring? Controller? Power supply? I did know that the thermostat wire was not rated for temperatures above 600ºc, but it had worked OK previously. So I turned everything off, and removed the electronics compartment. Changed the thermostat wire to the proper grade (thanks Stuart!), then found a loose main heater element join, so fixed that too. It all took another 1-2 hours.
Started up the oven again. The temperature had dropped to about 200ºc, but the the temperature started rising slowly, so maybe the problem had been fixed? By this time it was 4pm, and there were still 7 hours of heating required, so it WAS going to be a late night in the workshop. Made my peace with SWMBO. She was happily watching the footy, and not too worried about about my travails. (and our team won convincingly!)
To finish this story, I eventually poured the bronze, and my earlier concerns about the thin layer of investment at the bottom of the flask were realised. The bottom fell out, and molten bronze poured out through the breach. I normally rest the flask in a tray of sand when pouring, and fortunately, the bronze seemed to harden when it hit the sand, and the outflow ceased.
This was the result….
Amazingly, the parts seem fully formed, with no voids or bubbles. The ugly lump underneath is the bronze leak through the bottom. Note the length of feeder sprue. And the funnel. If you zoom into the photo you will see that the fine detail of the 3D printing has been reproduced. I will cut the parts off and finish them tomorrow. I got home about midnight. I needed that shot of single malt.The bronze brackets, after sawing them from the tree. I will add a photo after another session of machining and finishing them.After some more tidying. The investment powder can be persistent.
CHEAP SPANNERS.
I have several machines which use 40ER collets. I have enough collet spanners, but only one locking spanner for the chucks, and it is always on the wrong machine. So I decided to get some more locking spanners, and I sent my drawing to the laser cutting company. I picked up 4 spanners from them a few days later. Cost $AUD55. (cheap!)
My Colchester, with ER40 chuck. And one of the new stainless steel locking spanners. Drawn up as a dxf file, which was emailed to the laser cutter. The square hole is to lock the carriage to the bed. A few moments on the belt sander removed the sharp edges. Not elegant, but works perfectly.2 spanners are required to tighten the ER collet. Here I am making a jig which will be used to cut the quadrant gear which elevates the cannon barrel. More about that in a day or 2.
Not much happening to show visual impressions, so fewer posts, but lots of hours making bits function.
The three main gear shafts now have brass end caps. They will have oil cups drilled into the 12 0’clock positions next time the caps come off.
The adjustable parallels do not get a lot of use, but they are very handy to align parts in horizontal positions, like the holes in the end caps above. Especially when the girder is at an odd (4º) angle, and even the bottom of the girder is at 1º.
Currently I am planning the making and installation of the barrel elevation gears. Here is a PLA version, paper clipped into position.
Very handy having plastic versions to decide drilling positions etc. In the above photo is a plastic version of the main elevation gears, printed at the correct centres. The little bronze bit is the casting which is screwed to the barrel.
And just to demonstrate the current appearance of the cannons….. Lots of bits yet to be added, but it is exciting to see the size and form of the models.
Do you know what tension drilling is? Well, read on.
Having made the gears which position the carriage on the chassis of the Armstrong RML model cannon (I assume that regular readers will know by now that RML stands for “rifled muzzle loader”), I had to drill the chassis for the gear shafts.
There are 3 shafts, 8mm, 6mm and 5mm diameter. I knew the theoretical distances between the shaft centres by applying formulae taking into account module and tooth numbers. And also by using “Gearotic” software.
(I tripled checked with a lash up and direct measurement.)
But! I did not know the distance between the big gear and the rack gear. Because, the rack is attached to the base of the carriage, and the big gear is attached to the chassis. Considerations such as trolley wheel diameters, rectangularity of chassis and carriage, and position of the trolley wheels on the carriage all come into play. I will not bore you with details, but determining that measurement involved a lengthy, tricky, and complex setup using a surface plate, height gauge, adjustable parallels, straight edges, and averaging the errors. Amazingly, it turned out OK.
Then came a decision. To drill and ream straight through both girders at once, or to measure and drill/ream them individually. Luckily for me, I had a visit from GSMEE member Swen, (to borrow a tool), who is a retired ex-army Warrant Officer artillery fitter/turner. When I explained my dilemma, he was in no doubt. Measure them and drill them independently, he advised. So I did just that.
But, having invested many, many hours to date in making the chassis’, drilling a big (relatively) hole in the chassis girder was a very tense moment. (hence “tension drilling”).
Before drilling any more of the 6 holes required, I tested the fit between the rack and the big gear. Amazingly, it seemed pretty good. Maybe a little bit tight, but not too bad. So, I drilled and reamed the remaining holes.
Collars, splines, pins, bronze bushes and brake fittings yet to be made.
That photo represented a very long day in the workshop. I think that I arrived home about 9pm.
And there was a problem.
The big gear and its partner would rotate freely in one direction, but were catching and lumpy in the other direction.
Closer examination revealed that the teeth of the pinion appeared to be bent, allowing free movement in one direction only. Hmm…. how could that have happened? And how to fix it?
Root cause analysis of the issue concluded that the mill Z axis must have been bumped when I cut the teeth on that gear, causing them to be slightly off centre, producing the “bent” appearance. (the top photo shows the faulty gear. Can you make out the distortion?)
Solutions? Make a new gear. Or fix the distorted one. I decided to try the second option. I was not wanting to make another ratchet. So, I filed and tried, filed and tried, filed and tried…. you get the picture. And gradually the lumpiness disappeared. Several hours later, with blisters appearing, it seemed quite good, and will not be visible to casual inspection. You, dear readers, will be the only ones to ever know.
Yesterday I drilled the second chassis. I completed the task in only 2-3 hours. A fraction of time compared with the first one.
One of my readers made comment about the pliers which I used to hold the domes of 2mm copper rivets while I threaded them.
The pliers are worthy of comment, so I decided to say a bit more about them, and also some other pliers which are often used when I am working with tiny fasteners.
These are the pliers which started this line.
They are Japanese, not as expensive as some German brands, but beautifully made. And not inexpensive. “Engineer” brand.And these are the jaws. Note the transverse, and longitudinal hardened grooves/ridges. The longitudinal grooves are in cylindrical contours, so they will grip cylindrical objects such as screw heads and small cap screws, with ferocity. And not let go. These are the ones which I use to hold copper dome head rivets, with plastic tape covering to protect the copper.They come in various sizes. I purchased the two smallest. They are indispensable. Behind them are two other small pliers which I also use frequently.These are Maun parallel pliers. They also come in various sizes. These are the smallest. Incredibly useful. Do not damage tiny nuts or bolt heads. And will hold sizeable objects.……..and tiny objects.
Finally, the most expensive tiny pliers which I own……and probably the best…
Knipex Miltigrips, holding a 2mm nut. Parallel jaws. Incredibly strong. Beautifully made. Very expensive. totally indispensable. You should save up and buy a pair.
All of the above tools, and many others in my workshop, were purchased over many years at Qualitool Tools, 77a Mercer St, Geelong 3220. tel 035221 8915. David, the proprietor/owner is incredibly knowledgable and enthusiastic about tools, and was a supplier to the aircraft industry, and also to auto mechanics. He stocks only good quality tools. I often pop in there to ask “what is new?”, and invariably he will demonstrate some fabulously useful (read “expensive”) tool which I cannot continue to live without buying. If you are in Geelong, you should visit for a wander around Qualitools. David has no idea that I have given him this rap. Nor do I have any pecuniary interest in his business, except that I hope that it continues. I am happy to support it.
Another small bronze pour yesterday, and it was my best one yet. No bubbles. No voids. And excellent surface definition. What did I do that was different?
First, the 3D parts were printed already attached to the tree. So the trunk and branches were 3D printed with the parts attached. That meant that I could determine more accurately the bronze flow, the gaps, the spaces. The only “failure” was that I added some wax air vent sprues as an afterthought. And those wax parts were the only part of the pour which failed. Fortunately, the absence of the gas vents did not seem to matter.
The 3D printed tree. There are 9 PLA brackets ready to be replaced by bronze. I increased the height of the trunk for extra melt pressure. The air vents failed, and were not needed anyway.
Next, I painted the tree with a slurry of investment. The slurry was much more watery than the normal investment, but it was thick enough to leave a thin layer of investment on the surfaces, paying particular attention to the corners and internal edges.
Then I used my new, 1 hp vacuum pump to degas the investment mixture. It took about 15 seconds to reach maximum negative pressure, compared with about 1-2 minutes which the 1/4 hp unit was taking.
Then, after pouring the investment, I placed the full flask containing the tree and investment, and degassed the entire unit. I was shocked at how much extra air bubbled out.
The rest of the process was as usual, drying for 4 hours (except that this time it started at 6am, having put the process on an automatic start timer), burnout 2 hours, and baking 3-4 hours.
The cast tree was looking hopeful. And not much surface oxidation to see. (I had given the 15% phosphor copper a full 2-3 minutes to work this time.) ….and there are my brackets. 9 ducks in a row. They need a bit of filing, and some time in the gemstone tumbler.
BEVEL GEARS
Top is a bevel pinion as it arrived, and a mandrel which I made. Middle row is an unmodified bevel gear which is too big for the case. Bottom row is a machined bevel gear which now fits into the case, and a pinion on shaft, which also fits into the case.
While the investment flask was cooking, I experimented with the bevel gears which move the cannon barrel elevation. I had cast some bronze gears, teeth and all, some weeks (or was it months?) ago, but was not happy with the result. So, I had bought some bevel gears on Ebay. They are spare parts for an RC model car. Not quite the correct size, but close. The metal is HARD. Sintered? But, machinable with carbide cutters. (ps. added weeks later. Even carbide cutters struggled with machining these gears, so for the second set I used a tool post grinder on the lathe. That worked well, and produced a better finish.)
It all now fits.
Now before you all start shouting at me to make the bevel gears from scratch, let me just say that I might do just that. Not yet decided.
This was a feature of the model Armstrong RML cannon that I was not looking forward to. (to which I was not looking forward. Plogies to W Churchill. Something about split infinitives).
It is small, cannot be CNC’d with my degree of knowledge, and requires a lot of stuffing around. Which means filing. Or in my case, use of a Dremel.
This is the result after 5-6 attempts. It will have to do.
It is 11mm diameter, and 9mm long. Small and fiddly. And tucked under the cannon carriage out of site. As I said, it will have to do. 2 of them have taken several half days in the workshop. A bit of a tumble in the gemstone tumbler should pretty it up. (?should up it pretty?). The ratchet on the right slides on a spline. The gear spins freely until it engages with the ratchet.
Occasionally I have a good idea, try it out, and after it works, I think “I should have taken some photos of that for the blog”.
Today I had one of those moments.
This was the result….
This morning, at the GSMEE Zoom meeting, I asked my fellow members where I could obtain some rivets which I could NUT into position. The reason being that some rivets in my cannon chassis are located in impossibly small cavities. And the dome end of the rivets are visible. Apparently “rivet-bolts” are available, but I could not find a supplier by searching my usual suppliers. One GSMEE member had some spares in BA8, but I suspected that I would need more than his small supply. And I was concerned that the dome head size might not match my copper rivets already installed.
Then I had a brainwave! Why not put a thread on my existing copper rivets! So that is what I tried. And it worked!
The biggest issue is not damaging the copper rivet head while holding it and running a threading die down the shaft. The copper is very soft.
The rivets in the photo above have a shaft diameter of 2mm. And the head is easily damaged.
These are Japanese pliers, designed with longitudinal, and transverse grooves. Very useful. Beautifully made. And not cheap. But they do grip. The rivet at the bottom of the top photo is evidence of the gripping power.
So I tried this…..
A bit of electrician’s tape stuck to the jaws, resulted in minimal damage to the rivet head. See the top rivet in the photo.
And a 2mm threading tool was required…
M2 x 0.4 threading tool.
Holding the rivet like this does leave a 4mm non threaded length of rivet shaft, but it can be packed with washers, or something else. It works!
So that was my brilliant idea for today. HEY IT WORKS!
This was 4 days ago. Today. Re the gears on the right, bottom row…. one was machined from bar stock, the other was cast, had the outer ring removed, and a new ring soldered on, then the teeth were cut. Can you pick which is which? And all of the round gears have spent 3 hours in the gemstone tumbler to remove sharp edges. The tumbling has reduced the surface oxidation on the large gear castings, but some more time required to totally remove it.CNC milling the spokes in one of the intermediate gears. Neat job, but the internal corners with fillets are not really kosher. This gear is barely visible in the finished model.
And the gears with ratchets attached need 2 mates. I tried to make them yesterday, but we had a wild day with thunderstorms and high winds, and my machines were playing up. I might get back to them today. (the ratchets can be seen in the header photo).
In country Victoria we are out of level 3 lockdown! Hooray! Still can’t see family from Melbourne, and minor restrictions on visiting local friends, and need to wear masks when out and about. But things are on the improve. I doubt that we have seen the last of the virus however.
I spent few hours finishing the racks today. But not yet installed. Some photos.
Firstly the racks were surfaced…… then drilled, then given an outline using CNC.….then tested against their corresponding circular gears. But not yet installed.
For once, a job proceeded without a mistake. Hooray. Hmmm. Look at that big gear. Thinks… “I quite like that blackened inner area with the polished bronze hub and teeth”.
(p.s. For non-Australian readers, “rack off” is an expression sometimes used in Oz, when telling someone to leave or desist, in a forcible, but not quite foul manner. Used in the post heading in a hopefully, mildly humorous effort to be eye catching.)
The final gear in the cannon carriage positioning train is a rack gear. It is 198mm long, 7.2mm wide plus tabs for bolting it to the carriage of the model Armstrong cannon.
A rack gear is a flat gear, and it is cut with the same cutter (number 8) which makes a circular gear of 135 teeth or more.
The teeth of a circular gear are cut by dividing 360 degrees by the number of teeth. But the pitch of the teeth of a rack gear is determined by a formula found in Machinery’s Handbook. rack gear pitch = module x 3.1416. Which for my module 1.25 = 3.927mm. Hmmmm. 3.1416. That is a familiar number. Light bulb in brain switches on! A rack is just part of a circular gear of very large diameter.
At first I thought that I would use the same mill arbor which I had been using for the circular gears, but as soon as I started to set it up I realised that the stick out of the arbor would be ridiculously excessive. So, reluctantly, I set up the horizontal milling attachment of the mill. Reluctant, because the attachment is heavy, fiddly, and time consuming. Luckily, I had a 22mm shaft for the attachment, the correct diameter for the cutter. I had never used this shaft before, and it was missing the nut, and bronze bush. Bought it on Ebay years ago. Found a suitable nut and made a bush.
This is the setup. The 350mm shaft was not long enough to make the rack in one setup, and it took a bit of trial and error to work out the best compromise.
The horizontal attachment on the vertical mill. Setting it up takes me a couple of hours.No CNC here. Just lots of calculations using 3.927.
I need 2 racks, so I will split this one down the middle.
Did not have a piece of bar stock big enough for this job.
So I joined 2 pieces end to end with silver solder. Will that be strong enough? My friend Stuart T insists that a well made silver solder join is stronger than the parent metal, so we will see.It meshes nicely. The mounting holes (which I did not use) will disappear when the outsides of the 2 racks are shaped.
A bit of a story about that heavy horizontal mill attachment. When I bought it some years ago, I put it in the rear compartment of my SUV. But on the way home my SUV was T-boned by an idiot at an intersection. No injuries, but a big expensive dent to the passenger side of my SUV. Air bags activated. And the rear window was smashed. I could not figure out why the rear window was broken. After the police and fire engines had finished, and the tow trucks arrived (my car was out of action for 2 months, the other vehicle was a write off), a by-stander approached me with a familiar object which he had found in the gutter on the OTHER side of the 8 lane highway. Yep! It was the horizontal mill attachment. Been flung through the rear window by the violent impact of the collision, and across 8 lanes of the road. It was scratched, but otherwise intact. And thank goodness, it had not hit me or anyone else in its trajectory!
The big bronze gears on the bottom row were cast, had M1 teeth cut, had the teeth machined off, a bronze ring silver soldered on, and M1.25 teeth cut, which is what you see. They are almost finished. Above them are an almost finished M1.25 pinion and a pinion which will be parted from the stock bronze shaft tomorrow.
The right hand smaller gears are M1, with teeth cut. The right hand one started life like the ones on the left, but was a reject. I machined off the outer ring, and part of the spokes. and silver soldered on a new outer ring, and machined the M1 teeth. The similar solid gear has been made from bar stock from scratch. The spokes will be CNC machined, maybe tomorrow.
The bar at top has M1 teeth machined, ready to be bored for the shaft, and gears parted off.
The pinions for the big gears have a 4 tooth ratchet. This will allow the gear train for carriage movements to be disconnected for firing.
Making the big spur gear which pushes the gun carriage up and down the inclined chassis has been a bit of a saga.
For a start, I decided that fabricating it with lathe and mill was going to be very difficult, and it was an obvious candidate for casting. In bronze. After making a model with 3D printing in PLA.
So, I drew up a 3D model, saved it as an STL file, and printed it. But did not take into account shrinkage of the PLA part. Or shrinkage of the cast bronze part. So instead of 58mm diameter, the blank gear was only 57.4mm diameter. By reducing the number of module 1 teeth to 57, I could get a reasonable gear, and the teeth were duly cut.
But, module 1 teeth looked skinny and pointy and not correct. Plus, 3 of the cast gears were total casting failures and were discarded (remelted).
So, I machined off the module 1 teeth, made some bronze disks, and silver soldered them onto the cast central hubs and spokes, and machined the blanks to 60mm diameter. By this stage I had decided that the big gear teeth should be module 1.25. Chunkier. Looked the part.
But I did not have 1.25 module gear cutters. And no-one in our club had them for loan. So I ordered a set from China. Delivery any time up to the end of November!! Then I found 2 of the set from an Australian dealer, but they were priced almost as much as the full set of 8 cutters from China. But, thinking that they would arrive more quickly I bought them. They were Chinese. It is a seller’s market.
Then today, at our GSMEE meeting Swen P said that he had a set! And I could borrow them! So, gratefully, I did. And I cut the teeth this afternoon.
The module 1.25 gears at bottom. The module 1 gear top. Please tell me that you can see a difference.
While the teeth were being cut, I tidied up another bronze T rex.
Two of them now face off on my Trevithick engine. They should amuse the kids.
Next to cut the M1.25 rack. Should be straightforward.
My brother Peter, on reading my tribulations regarding the making of the big gear in the Armstrong RML cannon, reminded me of a saying of our father regarding any difficult job. That the job would not go well until some blood had been spilt.
My brother has not responded to my invitation to visit, in order that some some blood be spilt.
And to be frank, I have many so cuts and nicks and embedded splinters, that Hephaestus, the god of blacksmiths, should be happy….And, I have made some progress on the big gear…
Today I machined off the module one teeth, and silver soldered on a bronze blank disk ready for the module 1.25 cutters when they arrive. Yes, it was painful. Not sure if Hephaestus will be satisfied. But the invitation to my brother stands. If he will risk the Victorian Covid 19.
The module 1 teeth on the left gear has been rejected. So I have ground off the teeth on the middle gear and silver soldered on a blank disk ready for the module 1.25 teeth. Same with the gear on the right.and these are the big winding handles, with the defects repaired. I silver soldered in some segments from the reject handle to replace the defects. Can you pick the handle which was perfect? Not quite finished, but looking pretty good?
When bubbles occur inside a casting, the cause is probably in the design of the pouring system, or the way the melt was poured. If you watched the video a few posts ago by Prof. John Campbell you would think, as I did, that our pouring funnels and sprues should be more complex and more carefully designed. Difficult at an amateur level. I have made some changes in this direction, using a side reservoir to tip the melt into, and trying to avoid the gurgling and glugging.
With the sort of castings which I have been making for the Armstrong cannon, I am not so concerned about internal voids. The scaled down model always has an advantage in strength of the part, compared with the full size part, within limits.
But, bubbles which stick to the exterior of lost PLA/wax models are replaced by solid bronze, or whatever metal is used, and these metal bubbles can be tricky and difficult to remove.
I decided to remake the big gears, which were the subject of the last few posts, and the cause of a lot of bad language. I decided that the gear teeth were too skinny and pointy, and redesigned the part using larger module teeth. To compensate for PLA shrinkage and metal shrinkage I printed the PLA parts with a 2mm machining allowance.
The gears with the narrow pointy teeth.
I printed the PLA blanks, leaving the gears and brake drums as a blank lump which I will turn to shape after casting. But the internal decorative holes and ribs will be cast. And they are the site of many bubbles in previous castings.
So, to avoid the bubbles, I am trying something different in the current casting session. I am trying a method which was suggested by a GSMEE member, and that is to PAINT the first layer of investment material thinly on the tree components, making sure that no bubbles stick to the parts, then to pour the rest of the investment filling the cylinder. There might be some bubbles in the main volume of the pour, but they should not be sticking to the parts. That is the theory anyway. I am waiting for a bigger vacuum pump to arrive by post, which should be more effective at sucking out the bubbles, but meanwhile, I will try this…
The gear blanks, painted with investment, particularly in the bubble prone areas between the spokes.
Today, I heated 2 cylinders/moulds in the investment oven, and melted some bronze.
For the pour I tried the negative pressure apparatus.
I did not notice any change in the level of the molten bronze in the reservoirs when I applied the negative pressure, so I doubt that it added much to the process.
The results were like the curate’s egg… some good, some bad.
This was one cylinder. The reservoir/funnel at top, then 4 rather spindly round handles. The top one had a defect, the second was perfect, the third had a couple of small defects, and the fourth was unusable.The bottom one will be used to repair the 2 with small defects. There were 4 tiny parts in addition. 2 were excellent, 2 must have broken free from the tree and disappeared into the ether.
There were 2 big gears in the other cylinder. The one at the top did not fill properly and is not usable. It will be remelted. The bottom one was close to perfect.Note the absence of bubbles. I think that my pre-painting the investment into the recesses must have worked. The failed gear again was near the top of the tree. It seems that even bronze requires a bit of head to create filling pressure.These are the tiny 20x19mm fittings. Some time in the gemstone tumbler should polish them up nicely.
I am waiting for a more powerful vacuum pump to arrive by post. The 1/4hp one that I am currently using is too slow, when time is critical. I have a 1hp pump on order. No more casting until it arrives.
When my workshop activities mainly involved woodworking, I realised that concealing mistakes was a major skill of the craft.
As an amateur metalworker/model maker, the same principle applies.
So, today, I took a long hard look at yesterday’s disaster. (and apologies for my bad mood, and worse language. Actually, I toned down the language for the post.)
It was pretty bad. Huge gash, bent brake drum, damaged teeth.
And what I did is as follows….. first, a bit of amateur blacksmithing to bend the bent brake drum roughly back into shape. Then….
I found a bit of brass, and roughly fitted it in the big gash. Some belt sanding improved the fit. Then silver soldered it into place. I rested the brass shaft on a piece of brass as a heat sink. I really did not want that join to let go yet.… then bandsawed and belt sanded and turned it closer to shape…. then recut the teeth.… and it turned out pretty well, no?
Still some work to be done on the reverse face, but it is looking useable.
This time I wrote my own CNC gear cutting program. And it worked perfectly. And I used the same program to cut another gear.
Repaired gear on right. Some further filling, filing and machining required. But, nothing can go wrong now. OK?
After yesterday’s post my readers were very supportive and nice. Made the post worthwhile. Thanks readers!
So today, I machined off the bent shaft, silver soldered on a new bigger one, and re-machined the damaged brake drum. It looked resurrectable.
Silver soldering a new, bigger (13mm dia) shaft. Note the damged teeth, filled with silver, and the brake drum, hammered roughly into shape, and filled with silver.and then machined the shaft to 12mm, perpendicular to the gear face.And then milled new gear teeth….and it looked really beautiful. Ahhhh!
BUT!. There was a line in the gear cutting program which I had checked, but not noticed. It said Y0. 3 lines earlier the program said G0. If you program CNC you might make the connection. With 3 lines difference, I did not spot the problem. But this was the result….
Fuck, Fuck, Fuck.
The CNC mill did what it was told to do. Really buggered about 3 days effort. NOT impressed with Mach 3 Wizards for gear cutting.
I will look at it again tomorrow, to see if it is fixable, again. Excuse my French.
Actually, I think that you TRY to learn from your mistakes. It makes you feel a bit less stupid when you make mistakes. Or, at least, it puts a bit of worth into having made a mistake.
At the rate of my mistakes in recent days, I should be turning into an Einstein. Somehow, I doubt that is happening. I think that I will stick with my motto of avoiding making the same mistake more than 3 times in a row.
Yesterday, I was cutting gear teeth into the big gears which I had cast a few days earlier. Due to the mistake of not allowing for shrinkage of the castings, the wheels were almost 1mm smaller diameter than planned. (#1.). That meant that the wheels would have 55 teeth, rather than the planned 56 teeth. Not a big problem, just an annoyance.
Also, I had not cast a shaft in the gears, or any method of holding the castings for teeth cutting, (#2) so I had to drill a central bore, insert an 8mm shaft, and solder it in position. I should have used steel for the shaft, but for some reason I chose brass. (#3.)
Then, I could not find my module 1 gear cutters. The cutters, I knew, because I had seen them recently, were in a small cardboard box. I went to where they were usually stored, and they were not there. OK. I must have put them somewhere else. Then spent 2-3 hours searching every shelf, drawer, bag, box, floor, machine…. you get the picture. And could not find them. So I searched my vehicle, the other shed, and could not find them. Had I loaned them to someone else? Surely I would remember that? So I went and had a cup of coffee. Hmm. What next? OK, start searching again, going over previously searched spots in case I had missed them. So, first to the cupboard where they were usually stored.
And there they were. Exactly where they should have been. Well bugger me! (#4). There was a small upside to this long and frustrating search. I had found a few other tools which I had not seen for quite a long time.
So then I commenced the gear cutting. 55 teeth into the bronze wheel. The setting up of the CNC rotary table on the mill, attaching the cutter to the arbor, cutting teeth marks onto the circumference to check my calculation of the number of degrees per tooth (360/55 = 6.545454º….). All going well. Each tooth required a cut 2.66mm deep. But I was a bit concerned about that 8mm brass shaft. Would it bend under the pressure of the tooth cutting?
So, I cut the teeth in 2 stages. 1.5mm deep for the first cut, 2.66mm for the second. The first cuts went well. Looking good. After a complete circuit, the partly cut teeth were all even, and gleaming. So, onto the full depth of 2.66.
DISASTER! (#4.). When I attached the cutter, I had carefully placed it on the arbor so that the securing nut would tighten, rather than loosen with the cutting process. But I had got it wrong. Totally wrong, and it loosened! BAANG. I hit the big red button. The mill spindle stopped, but the now loose cutter was still spinning wildly. What if it comes off while spinning like that? Would it fly across my workshop, cutting whatever it hits? Like me?
When I bought a woodworking spindle moulder many decades ago, an uncle advised me to NOT use it. He had seen a co-worker die, when a cutter flew off a spindle moulder, slicing into his abdomen. I did use the new spindle moulder, but with great caution, and never had any problems.
Visions of the gear cutter slicing into my belly.
But, the cutter slowed, then stopped, to my relief.
A quick look at the workpiece was disheartening.
The brake drum attached to the gear was bent . A spoke had a big gash. The tooth which was the culprit for this disaster was gashed too deep. and the shaft was bent to a crazy angle.
First thought. “Bin it and start again”. Steps to make another big gear. 1. 3D print a new PLA gear (with machining allowance this time, and include an oversize shaft). 2. Make a casting tree. 3. Mix and pour the investment. 4. Dry, burnoff, and bake the investment. 4. Melt the bronze and pour. 5. Machine the gear blank, cut new teeth. 2 days estimated, if all goes well.
Oh well.
No photos of the damaged gear. Not in the mood. But I did take a closer look. I wonder if it can be repaired. Maybe the distorted brake drum could be bent back into shape? Or cut off totally, and silver solder on a new one? Fill the defects, and tidy up the damage.
I decided to call it a day. But first I used a hammer on the damaged bronze gear brake drum. Somewhat to my surprise, it went back into reasonable shape, without cracking. So, a bit more tapping, and it looks quite good. It will require a bit of filling and filing, and machining, but maybe it is resurrectable.
After a sleep, and fresh look, I relented and took a couple of photos.
But what about finishing cutting the gear teeth? It will need a new shaft. My plan is to machine off the bent shaft, insert a new steel shaft while holding the external circumference of the gear in the lathe chuck. Might just work. If the over-gashed tooth looks too odd when I finish cutting the teeth, I will fill the void with bronze or silver and re-machine it. Watch this space.
Just to recap, I made the trees and investment powder moulds about 2 weeks ago.
The biggest gears on the Armstrong cannon. Some with cast teeth, and some with blanks for teeth to be cut. And some brackets in red on top.And the 2nd tree has 6 brackets on top, and another T rex to fill the spare space.
The first problem was that when I was adding the carefully weighed and expensive investment powder to the carefully weighed water, the f***cking scales timed out and shut down. So I had to guess the amount of powder to add. Then mix furiously. Then a briefer than normal degassing. All to be completed in 10 minutes. 10 minutes sounds like a long time. But it is all too short when there is any hick-up at all. (read.. “stuff -up”). #1.
I knew that the scales had a shut down timeout, and following the Chinglish instructions, I thought that I had turned the timeout off. But apparently I had not. After that I ordered some new scales.
Then I had to wait almost 2 weeks for the 15% phosphor copper to arrive.
Yesterday, after installing a new heater element in the melting furnace the day before, I fired up the investment oven and went through the drying, burnout and baking cycles, about 8 hours. And prepared another tree and mould for the next pour, in a few days time.
The melting furnace with its new element took a lot longer than previously to melt the bronze ingots, about double the time. But that was OK. Just had to ring SWMBO to warn her that I would be very late. (Got home about 9pm. She had organised take away.)
I added the 15% phosphor copper in approximately the recommended amount. And poured the first cylinder. But I forgot to wait the recommended 2″. #2.
Then I poured the second mould. And there was not enough melt!!!! #3. I had underestimated the amount of bronze! Those 4 big gears were guzzling the molten bronze! So what to do? Abandon the second cylinder? Or melt another ingot and just pour it on top of the first one after another 30-45″?. Nothing to lose, so I plopped in another bronze ingot, and waited for it to melt. Meanwhile I put the mould half filled with bronze back in the investment oven to keep it warm at 710ºc. Then, for some reason, the electronic controller of the investment oven shut down, and the element stopped heating. #4.
When the extra bronze melted I added bit more phosphor copper and completed the pour into the now substantially cooler mould which was already half filled with bronze which presumably had solidified. I assumed that the join between the 2 pours would be a problem. And it was.
Forgot my camera. Some photos to be inserted here later.
Somewhat surprisingly considering the guessed amount of investment powder at the original mix, and short duration degassing, the first mould was, apart from a few bubbles, completely successful. The second mould, with its 2 pours, was not a total disaster.
Today I sawed apart the trees, removed the bits of sprue and vents, and partly machined the parts. These are the bits.
The toothed gears and non toothed gears are the biggest gears on the cannon. And they include the drum brake, I was unsure whether the cast teeth would be adequate, or whether I would need to cut the teeth. It was not a fair test, in view of the interrupted pour, and the brief degassing. But I will cut the teeth from the blank wheels to the right. The toothed gears were probably the join between the 2 pours and total failure and will be remelted.
Even the blank wheels are not without problems. I did not allow for shrinkage, #5. and the diameter of the wheels is 57.5mm instead of the intended 58mm. So I cannot cut 56 teeth per wheel. I can cut 55 teeth on the smaller diameter. Still pondering that one. Do I repeat the entire exercise with a machining allowance? Or just be satisfied with one tooth less? I have not decided definitely, but am tending towards accepting a slightly smaller tooth count.
But, at least the brackets to the right came out well. This photo was taken after some belt sanding….not perfect, but not bad at all.
Incidentally, the T Rex is quite good. substantially less surface oxidation, and the oxidation layer that was present came off much more easily. Next pour I will add a bit more of the phosphor copper. And I will wait the recommended 2″.
It arrived today. Rather uninspiring small grey bits of metal about the size of rice grains.
But how much to add to the melt?
So I searched the net and found this.
Description: 15% Phosphor Copper Shot is use as a deoxidizing agent for copper, brass & bronze alloys. It will also increase fluidity and inhibit gas porosity. The shot we carry is approximately 1/8″ x 1/32″ in size.
Usage: Melting of brass, bronze and copper should be done quickly in a slightly oxidizing atmosphere. The crucible is removed and surface is skimmed, then phosphor copper shot is added by simply dropping it onto the surface. The reaction is very visible. The metal will become fluid and bright. Allow a minute or two for the reaction to complete, and pour.
The phosphorus is a reducing agent (deoxidizer). This product must be carefully measured so that enough oxygen is removed, yet a small amount remains to improve fluidity. Too much phosphor can cause the melt to be so fluid that it leaks from the mold and penetrates the sand. A little goes a very long way!
The primary reason to use the shot is because the molds aren’t filling well or have gas porosity problems. The literature suggests that 1 ounce of 15% copper phosphor shot be added to 100 lbs of metal. A teaspoon of shot weighs about 1 ounce.
Start with these amounts: 100 Lbs add 1 Tsp. 50 Lbs add 1/2 Tsp. 25 Lbs add 1/4 Tsp.
For lesser amounts start with about 1 to 4 granules per pound of metal
The video featured in this post is fairly recent, and will probably be of interest only to those who are actively involved in casting, and those who like to keep up with developments.
While aimed mainly at industrial level casters, there are lessons which amateur casters can apply.
Thanks to GSMEE member John Bernoth for sending me the link.
As a very amateur beginner, the video made me aware of how little I know about the subject.
You can watch the video on the small screen here, or find the YouTube link to watch it full screen. The video quality is pretty ordinary, but the message is, I found, very interesting.
ps. waiting for the 15 phosphor copper to arrive by our very slow post before I do any more casting. Still in level 3 lockdown. I am making a negative pressure pouring apparatus, almost finished, but after watching the above video I wonder if I am on the wrong track. Maybe I should be thinking about bottom filling, spinners, and restricting the flow rate.
The heavy plate with the hole is connected to the water chamber on the left. The mold cylinder will sit on a silicone pad which will have a corresponding hole. The hot air will pass through a copper coil in the water chamber to the left, and the cooled air will then go through a tube to the evacuation chamber and then the evacuation pump. The filler and drain plug positions were determined by pre-existing holes in the copper tube.
My bronze castings had been coming out of the investment mould looking like this. I had been expecting to see a wonderful shiny golden bronze colour, and was a bit disappointed in the irregular black coating. But the casting itself was complete, with no voids, and having fine details like fingers, and 3D printing marks showing up clearly. And after laboriously attacking the black coating with Dremel wire brushes, files, sulphuric acid (ineffective), a lot of the black was removed.
This baby T Rex has found a home on my model dredger engine. The variegated skin colouring is reasonably convincing, but was not the shiny bronze colour which I wanted.
Maybe a problem with the LG2 bronze ingot? Something else?
So, I telephoned the supplier, Clingcast Metals, Sydney. Paul answered the phone, and he knew exactly what I was describing. “copper oxidation. Did you add 15 phosphor-copper shot to the charge? (The “charge”, I gather, is the crucible loaded with bronze pieces, for melting?)
“No. What is 15 phosphor-copper shot?”
“Small metal balls. If you add a tiny amount to the charge you will avoid the surface oxidation which you are experiencing, AND it will make the bronze melt thinner and run more freely.”
“Great. Where do I get it.”
“Oh. We have heaps here.”
“Would you post some to me?”
“Sure. How much do you want?”
Quickly thinking….”Maybe a kilogram”.
“That will last you a lifetime. $15, plus postage”.
“Fantastic.” – but I can’t find my credit card. Darn.
Paul. “I will post it. Just pay us when you get around to it.”
So, no more casting sessions until the 15 phosphor-copper shot arrives.
And big kudos to Clingcast Metals.
Meanwhile, I am making up trees and moulds.
Another T Rex, and some cannon parts.The transparent PLA disks are the biggest gear with brake drum. I have not yet decided whether to cut the teeth on this part. And the red PLA parts are brackets for the cannon chassis.
Also meanwhile, I noted that Banggood have a special on melting furnaces which seem identical to the one for which I paid $425, and I have seen advertised at up to over $500. Banggood are asking $AUD290 + $20 p&p. So I have ordered one, as a spare. If you are interested I suggest that you check out this special, ASAP.
p.s. 2 Sept 2020. The 15% phosphor copper arrived today. I found this info on how much to add. I think that my 1kg will last a lifetime.
Description: 15% Phosphor Copper Shot is use as a deoxidizing agent for copper, brass & bronze alloys. It will also increase fluidity and inhibit gas porosity. The shot we carry is approximately 1/8″ x 1/32″ in size.
Usage: Melting of brass, bronze and copper should be done quickly in a slightly oxidizing atmosphere. The crucible is removed and surface is skimmed, then phosphor copper shot is added by simply dropping it onto the surface. The reaction is very visible. The metal will become fluid and bright. Allow a minute or two for the reaction to complete, and pour.
The phosphorus is a reducing agent (deoxidizer). This product must be carefully measured so that enough oxygen is removed, yet a small amount remains to improve fluidity. Too much phosphor can cause the melt to be so fluid that it leaks from the mold and penetrates the sand. A little goes a very long way!
The primary reason to use the shot is because the molds aren’t filling well or have gas porosity problems. The literature suggests that 1 ounce of 15% copper phosphor shot be added to 100 lbs of metal. A teaspoon of shot weighs about 1 ounce.
Start with these amounts: 100 Lbs add 1 Tsp. 50 Lbs add 1/2 Tsp. 25 Lbs add 1/4 Tsp.
For lesser amounts start with about 1 to 4 granules per pound of metal
One to 4 granules per pound of melt! It really will last a lifetime. My crucible will melt a maximum of 3kg/6.6lb.
The model Armstrong cannon has 7 gears, 2 of which are bevel gears, and 5 spur gears, including one quadrant gear.
4 of the original spur gears. These position the carriage on the chassis for loading and firing. There is also a decoupling mechanism on the second shaft. (Portland cannon)
The spur gears will be machined and cut from bronze, brass or steel. I have a set of module 1 cutters, which are close in 1:10 scale to the originals which are close to module 10.
The bevel gears I have made by casting them in bronze, teeth and all, and they are pretty darned good. Not perfect, but they will be hidden from sight in the gear case. They seem to mesh pretty well, but, if they are not up to the job of elevating the barrel I will cut some replacements.
The biggest gear is a spur gear, and it has a brake drum as part of the casting. It is a bit more complicated than a simple cut spur gear. Apart from the brake drum, the gear teeth have flanges at each end of the teeth, which will make them difficult to cut, unless I add the flanges later. I guess that the original was cast, teeth and all.
From below, the biggest gear with the brake drum on the left of the picture. The brake band is a steel band. (Port Fairy cannon)
I have decided to cast this gear also.
You can see the flanges more clearly in this photo. (Port Fairy cannon)So I have 3D printed casting blanks with teeth and flanges (left) and without teeth and flanges (right). I will cast both, then decide which to use. 58mm diameter, 25mm wide. The prints are colourless PLA. I have had problems with plate adhesion with this PLA.The bevel gear case. Cast bronze. Some more finishing required.The cast bevel gears. Since this pic I have machined bores and improved the finish. PLA blanks.And can you guess what this fingernail size piece is? It will cast in bronze.
I found out the answer to this question today, unfortunately.
This is the PLA + wax tree which I wanted to cast. There are 3 bevel gear cases, for the Armstrong model cannon.
There are internal cavities for the bevel gears, holes for the shafts, and external/internal surfaces, quite a complex shape.
Yesterday I mixed the investment, and poured into the flask, around the tree. It was a tight fit in the flask. I had miscalculated the flask diameter, and some parts were probably touching the metal cylinder. So I was not too confident about a good outcome. But I went ahead and commenced the drying out, burning out, and baking cycles. About 7-8 hours altogether.
Then started the bronze melt in the electric melting furnace.
Strange.
The temperature was not rising.
Usually, 1100ºC was reached in 30 minutes or so.
But it remained at 19-20ºc. Ambient temperature.
Penny dropped. Bummer. The Melting furnace was RS.
6 months old, still under warranty. But how long would it take to get parts or replacement from China? Email sent.
And what to do about the already prepared investment flask, happily baking away? So I turned off the investment oven, and let it slowly cool down.
Discussed the situation with Stuart. Probably burnt out the heating coil, but could be the relay or the control unit. Whatever, it will take days/weeks/months to sort out. Bummer.
Stuart: “You can borrow my spare unit”.
Me: “you have a spare melting furnace?”
Stuart: “sure”. “you can borrow it”.
Me: “wonderful, thank you”
So today I wondered if the investment flask could be reheated to 710ºc, and accept the molten bronze. Stuart: “Don’t know. Never done it”.
So today, I reheated the investment flask to 710ºc, over 3-4 hours, held there for an hour, melted some bronze in Stuart’s loan furnace, and poured.
Here is the result.
3 almost perfect gear cases. I have removed the sprues and funnel and most of the investment. Not showing up well in the photo, but I have demonstrated that the investment mold CAN be reheated. I will machine off the unwanted bits and surfaces tomorrow.
Casting with bronze seems a bit more forgiving than with aluminium. And Investment mold, at least with Goldstar Omega Plus, CAN be cooled and reheated without cracking up.
And a replacement heating coil will be sent from China. Maybe I should buy a spare melting furnace.
In common with every modeller, woodworker, metalworker, boat builder, surgeon, “hands on” person that I have ever met, I love tools, particularly tools made with thought and care and passion for quality.
And, although I have never been a knife maker, I have been a frequent watcher of “how to” make knife videos. Who knows, maybe I will branch out into that hobby one day.
This post was prompted by my purchase of a new knife. Undoubtedly the sharpest knife I have ever used. At first glance, it has an attractive, basic shape, and I thought, “that will make a good kitchen knife”. It is long and slender, not for chopping sweet potato or pumpkin, but more for fine slicing of tomato, or coriander. (or meat/fish if you are a Neanderthal).
And sharp! It is sharper IMO than a surgeon’s scalpel. It passes the paper held at one edge slicing test with ease. I could shave with it, except with a 8″/200mm blade, that would be a bit terrifying. Even cutting up vegetables is an activity to be approached with caution. A touch on a finger would end up as a trip to the casualty department for stitches.
The knife is Japanese. Of unknown age. Probably handmade.
It was offered to me by GSMEE member Neil, who has a substantial collection. One glance at the photo he sent to me was enough for a “yes please”.
The knife, and its wooden sheath.Can anyone translate this? The handle, ferrule and blade are asymmetric. The grip is quite positive. Previously I have rejected asymmetric blades because they tend to deviate sideways while cutting, but this one, for some reason, cuts straight.
The wooden sheath is not Japanese. It was made by Neil, and the blade snicks perfectly into place. The pattern on the sheath is unique, and random. Looks the part, no? Considering the terrifying sharpness of the blade, the sheath is an absolute necessity IMO.
Japanese knives, chisels, saws and other implements are available from Tetsu, Ocean Grove, Victoria, tel 0403 549485. If you want a knife with a fitted wooden sheath (strongly recommended), contact Neil McMeekin at neilmcmeekin@bigpond.com. tel 0491 212 258.
Actually, I had some spare space on the tree which I used to make some more small gears, and I had some PLA T. Rex’s, so I added one.
And this was the cast result, in bronze. Yet to be cleaned up, tree bits ground off, and polished..
Again, the gears are close to perfect. I like bronze.
And the gears have a short length of shaft, printed in PLA and cast in bronze, which I will be able to hold in a chuck for tidying and turning. Lesson learned. Think ahead, how the cast part will be machined….
And at our society Zoom meeting, Frank M asked about the colour of burning Borax. I could not remember, so took a shot today…
I would describe the colour as white-gold, with a touch of green. Like a volcano. Maybe I overdid the Borax?
Oh. And I had a brainwave. When degassing the investment mix with negative pressure, add some vibration. I tried applying my sanding machine once, and filled the room with old fine sawdust. But for this session, I placed the vacuum pump on the vacuum chamber, and could hardly believe the volume of air which came out of the mix. The best degassing to date.
and it takes less bench space. A no-brainer. Try it!
The bronze gears which I cast yesterday were cut off the tree with small bolt cutters, band saw and hack saw. Then a belt sander to reduce the daggy bits.
The gears, and the tree trunk and branches which will be remelted.
The faces needed to be flattened in the lathe, but how to hold the rather thin, delicate, irregular gears?
Soft jaws.
Soft jaws made of aluminium, and exactly machined to match the external diameter of gear teeth, so there are multiple contact points, and minimal chance of damaging the teeth. I made these soft jaws ages ago, for just this sort of job.
The soft jaws are machined to exactly fit the workpiece.
The soft jaws may be used multiple times, machined to shape each time. Very handy in this situation.
The larger gears are good. I silver soldered some extra material on one of them for the shaft, then turned the shaft to size . But, holding the small pinion gear is more problematic. I will need to machine a soft jaw with a taper to hold the teeth. Next session. I should have anticipated this situation and designed the gear with a shaft to be PLA printed as one piece.
Bevel gears seem to me to be rather difficult, even with CNC control of X,Y,Z and A axes. The bevel gears on the model Armstrong cannon are rather small, being 32mm and 14mm outside diameter.
I read Ivan Law’s book on the subject, and I think that I understand the requirements, and I was prepared to try and cut the gears. But, first, I decided to try to cast them.
That involved…
Using “Gearotic” to design the gears, and save them as an STL file which was able to be imported into the 3D printer.
Made PLA gears with the 3D printer.
Attached the gears to a wax “tree”.
3 pinions and 3 gears. I need 2 of each. 1 spare of each. Plenty of venting sprues. And a head of about 70mm.
4. Then mixed the investment, poured it into the flask. At least that was the intent. The investment makers specify exactly 40:100 by weight of water:powder. But the bloody scales switched themselves off while I was adding the powder to the water, so I had to guess the quantity of powder. This was not looking promising. First bronze casting pour not off to a good start.
5. Dry the mold flask in the potter’s oven for 2 hours, then 2 hours of burning out the PLA and wax, then 2-3 hours of baking at 750ºc. A few minutes into the burnout phase, the oven died. ?heating coil failure, ? control box failure?, ?thermocouple failure, something else? So I replaced the control unit and thermocouple (I had a spare of each), but problem persisted. I rang my expert friend for advice. “sounds like a broken wire” he says. Suggested 3 or 4 things to try. And the 4th suggestion worked! The oven was working again! Brilliant! Thanks Stuart Tankard. So I restarted the oven at the burnout temperature (400ºc) and continued. Nothing to lose, after all.
6. Melted a couple of bars of LG2 bronze at 1100ºc in the melting furnace. Added a pinch of Borax. Let the investment oven cool to 710ºc for 1 hour to let the core of the mold cool to 710ºc.
7. Without any great expectations of success, considering the various problems, I poured the molten bronze into the mold flask. It seemed a bit more viscous and thick than I was expecting. Oh well. It is experimental.
8. When the mold flask had cooled to 150ºc, I plunged into cold water, and flushed out the investment.
THE RESULT….
Unbelievable. No voids. Hardly any surface bubbles. ALL teeth intact and complete. 6 good gears! You can see the head of molten bronze between the funnel and the top gear. It did not need vacuum or positive pressure.
I will turn the faces, bore the shaft holes, and if necessary file the teeth.
Totally delighted with this result. Beginner’s Luck.
I did not expect these mounts to require a third day session, and they are still not finished!
I discovered that two of the drilled holes in each bracket were in the wrong position, by approx 1mm. That is a really bothersome error, because the correct position includes half of the existing hole.
I managed the problem by threading the errant holes, and Loctite gluing in some threaded rod. Each rod was trimmed flush with the surfaces. Then drilling the new hole, partly through the Loctited metal patch. That fix worked well.
Threaded rod glued into the errant hole. Trimmed flush later. Then redrilled correctly.
THE TRUNNION PINS.
The pins hold the trunnion caps in place. And they took another whole day to make and install. Ah…. just as well I enjoy all of this. They are tiny, and I spent at least 50% of the time looking for them on the workshop floor after accidentally dropping them on several occasions.
Milling the pin handles from 2mm steel. The handles ended up at 7mm long. The holes were drilled before the outlines were cut. Then the tabs were ground off using my newly made belt sander belt. The belt lasted 15 minutes before the belt itself tore, with the join still intact!
Then some delicate silver soldering of a ring to attach a securing chain later, then the pin shaft itself. The wire through the ring is just to hold it in position during soldering.
And that is one of the 8 pins made. I will polish them in a gemstone tumbler next session.
On the model, the pins are jammed into position with a cam action, after some filing-shaping. On the original cannon there was a small protrusion on the inner end of the pin shaft, which fitted through a slot in the side of the carriage. I could not figure out a method of making such a tiny slot (1mm wide x 1mm deep) through 4mm of steel plus 2mm of brass, but the cam action seems effective. I will attach some chain soon, because I do not wish to make any more of these. And yes, the pins handles are slightly over-scaled, but I think not outlandishly so.
So, apart from polishing riveting and painting, I think that the trunnion mounts are finished.
Now planning to make the gear train for the carriage positioning on the chassis, and the pinion, quadrant gear, and bevel gears for the barrel elevation. We are currently in level 3 lockdown for Covid containment, with level 4 looking likely any day, so obtaining brass for the biggest gears is difficult. I am considering workarounds. Apparently community anxiety and depression, family violence, and even suicides are mounting. When I am in the workshop I am in a different world, thank goodness.
This idea is not original. I spotted it on YouTube.
I have a very nice small bench belt sander made by Sorby UK. I don’t use it often, because the Australian made Radius Master is much more versatile and powerful, but occasionally it is the tool of choice. Problem is the belts. They are a really odd size. Not available on ebay, and they are expensive. So when I saw this method, I decided to try it.
Basically, you buy a roll of relatively inexpensive 50mm wide sanding paper, and make your own belts. The issue is, the join.
I have had this roll, and several others, for years, using a few inches at a time.
I removed the old belt, cut it along its join, and used it as a model to cut some pieces off the roll. The angle of the cut was 30/60º. I used Tullen cutters in preference to scissors.
And this is the method of the join. Use “Iron On Mending patch”. Freely and cheaply available on Ebay, and in haberdashery shops.
I asked SWMBO if she had some spare IRON for my workshop, and this was produced. Sorry about the confusing ironing board pattern.
Important: the ends of the cut sandpaper are precisely aligned, and the side edges are lined up against a straight edge. Then the mending patch, cut a bit oversize, is laid on the join, and the heated iron is applied according to the instructions on the mending patch. In this case the iron was heated to “cotton” heat (whatever that means) and pressed down for 25 seconds. Best to use some brown paper underneath, otherwise the patch will glue to the ironing board cover.
Then I tried it. Click on the arrow to see a short video.
So, the test was surprisingly successful. Later I made another belt, and applied the patch obliquely, at the same angle as the join. It was MUCH improved, totally removing the noise of the patch running over the workpiece. I would certainly recommend this modification.
This patch was applied straight across, but it was a bit noisy and I kept wondering if it would hold. It stayed intact. But an oblique patch is better.
After some use, the join opened about a millimeter, but remained intact. I probably should have let it cool totally before using it. Or maybe the patch fabric in this case was a little stretchy.
I think that this will be a good method, and I will continue to use it. It is inexpensive. I got 4 joins per $AUD5 patch. I suspect that I overdid the size of the patch, and could probably get double the number of joins from this size material. Try it!
Today, for the first time since I retired 5+ years ago, I wore a face mask. In my professional life I wore them for 4-6 hours at a stretch, and never thought twice about them.
But in retirement, and with Covid social restrictions, I have not shaved for 6 months.
And grew quite a respectable beard and mo.
But with the mask on today, because I had passengers in my car, I was obliged to wear a mask.
It was hot, my beard got in the way and was scratchy, and my glasses fogged up. And there will be at least 6 weeks more of this…..
So I decided the growth had to go…..
After the dog clippers….
and then a blade…..
SWMBO has not commented yet. Maybe she has not noticed. I know that she detested the beard.
It took a whole day making and fitting the top caps of the trunnion mounts from brass.
A 76 x 76mm piece of brass was milled to 10mm thickness. The trunnion straps will finish at 9.5mm , giving me a 0.5mm machining allowance.
The 4 straps were cut out using a new 4mm endmill. Rounded internal corners were milled square, and the bottom tabs were milled to 2mm thickness.
2mm wide slots were milled into the brackets, and ends of the slots were filed square. None of my rifling files were small enough, so I ground one to size, leaving the faces and one edge intact.
Trunnion mount almost finished. Pins in the tags to come, and they will pull the strap down tight with a cam action. The half circle line on the bottom bearing is a painting border to delineate the bottom bracket from the bronze bearing surface which will not be painted. If you inspect the full size trunnion in the previous post you will see what I mean.
Now I can take some measurements of the model, and start the barrel elevating gear. There are 4 gears to be cut, including bevel gears, handle, shafts, gear case, and some complex mounts.
On the Armstrong 80 lb RML model cannon, the trunnions are secured to the carriage with steel brackets riveted to the carriage sides, and the trunnions rotate in a bronze bearing.
The original trunnion on the Port Fairy cannon
These are the component parts.
The RSS ready for cutting out the brackets. And my working drawing, with alterations.
First the 2mm rivet holes were drilled, then the outlines were CNC milled. The steel is 2mm thick.
Tidied the parts with a file and belt sander.
The brackets sitting on a photo of the original Warrnambool cannon.
The bronze bearing involved some basic lathe work.
Then the components were silver soldered together. Delicate work. I did not want the solder running into some areas, and the join needed to retain a degree of precision.
After cooling, sulphuric acid soak, and washing, the top half of the bearing was milled off.
Some filing to make it fit the carriage, then rivet holes drilled with a Dremel while the bracket was clamped in position.
Bolted in position temporarily. Tomorrow I will make the top half of the bracket. The gap between the bracket and the carriage caused by the metal folding will eventually be filled, and invisible. A millimeter or so will be removed from the width of the bracket and bearing.
I had a bit of milling excitement while cutting out the steel components. I was using a 6.35mm 4 flute carbide cutter, and when I started the program the machine plunged into the shape at extremely high speed. When I checked, the feed speed was 60 times higher than I had specified. Somehow, the units had changed from mm/minute, to mm/SECOND. Amazingly, the cut was close to perfect with no damage to the workpiece. But, alas, it wrecked the carbide cutter.
I had recently upgraded the CNC software (Vectric V-Carve Pro) from version 10 to 10.5. Maybe some of my settings in the program had been changed in the upgrade? I never use mm/second. That is a woodworking CNC router unit.
I needed 20 spacers, 2mm thick, 13mm OD, 5mm ID, to finish the carriage axles for the Armstrong model 80pounder RML.
I could have turned some 13mm OD, drilled a 5mm hole, and parted off the spacers in my lathe, but I know from experience, that the pieces never end up exactly the same thickness (in this case, 2mm thick).
So I decided to try a Banggood tool which has sat unused since I bought it many months ago.
It is a HSS hole cutter. 18mm OD, but the disk removed is 14mm OD, just a bit bigger than I wanted. 2mm thick waste brass plate.
So I cut off 25 disks, from a piece of waste brass, 2mm thick. The Banggood tool worked well, except that it need swarf picked out after almost every disk. But it was quick, reasonably accurate, and the central drill bit was 5mm, just what I wanted.
The disks were slid onto a 5mm capscrew bolt, and nutted down hard.
The head of the capscrew was held in the lathe chuck, and the tail of the threaded end in a shop made tapered tailstock socket. And turned to 13mm diameter.
About 12 spacers made per run. Very quickly. Reasonably accurately. A bit of tidying to follow.
The Banggood tool worked pretty well. I will buy some more of these. They were quite inexpensive.
Today I polished the ends of the trunnions, being careful not to remove the lasered lines and markings. I used a 200grit sanding pad in a sponge backed sanding disk in my milling machine. Also worked very well. I removed about 0.1mm of steel, without destroying the markings.
Well, I found it interesting. Maybe says something about me.
My 2 carriages have 20 wheels and 20 axles between them. Plus the 4 big ones under the chassis’. I had made the wheels. The axles required some planning and thought, after all, whatever I did was going to be repeated at least 20 times.
I decided on stainless steel for the axles, and brass for the end caps. The originals were steel, but they will be painted, so the appearance of the metal is irrelevant.
First steps were to cut up 20 pieces of 5mm stainless steel, 25mm long, and drill 5mm holes in 12.7mm brass rod, and part off 20 pieces 5mm wide. With a few spares.
The the brass end caps need to finish 4mm wide, so there was a machining allowance of only 0.5mm on each face. So the silver soldering of the 2 parts needed to be reasonably precise.
To assist with keeping the brass disks square to the rods while soldering, I drilled some 5mm holes in an aerated concrete block, exactly 21mm deep.
Fluxed the mating parts, and silver soldered 5 at a time. Very quickly. I could have used Loctite 620, but would have had to wait until it cured before machining.
A soak in sulphuric acid for a few minutes, then a water rinse.
Then turned the end cap shape on the Boxford TCL125
Not quite finished. M2 Holes to be drilled through the end caps, and threaded to the brackets. I will use the CNC toolpost milling attachment which I made in 2019. That might warrant a short video.
A short video. Well, a bit over 5 minutes…
The capscrews are not kosher. The original cannons had large slot screws. But will anyone notice? (idea… I could fill in the hex hole with JB Weld, and machine a slot?!). Maybe.
In retrospect I could have done the entire shaping and drilling and milling of the brass end cap using the toolpost mill on the CNC lathe. Would have been a lot more efficient.
Back to the model Armstrong cannon carriage this afternoon, and fitting 2 internal transoms, which provide rigidity to the carriage.
The transoms had been laser cut some months ago. I cut the floor from 2.8mm stainless steel.
Each transom is attached to the sides and floor by angle iron, 2mm thick. In the original cannons the angle iron was mitred at the corners, and for this model “A” carriage I decided to try to replicate the mitres.
The angle iron was again bandsawn from RSS tube and milled to 10x10mm. I used the following setup to form the 45º angles…
This is the Eccentric Engineering tool sharpening arm, set up to 45º on my RadiusMaster belt sander, about to form mitre angles on the angle iron resting to the right.
The Angle iron pieces were glued to their respective transoms, and 2mm holes drilled. Bolts progressively inserted. The lengths and cutouts will be trimmed later.
Then milled and filed the corners until the parts fitted neatly into the carriage. Rivets will be inserted later.
…and for your interest/amusement, depending on your UFO opinion… Listen to the information, and try to ignore the appearance of the narrator.
….and do I think that UFO’s are real? I would say that my “belief” has risen from 95% to 99% YES. One of my readers, with whom I have spoken directly, and for whom I have no doubts about personal veracity, has seen one at close quarters. Do I think that they are of non human origin? A bit less positive about that one, but it does seem more likely than not. Waiting to see if and what NYT does publish.
Friction welding is a technique which is used in industry. It involves rotating 2 metal surfaces against each other, under considerable pressure. The heat generated from the friction is enough to make the contact surfaces to become red hot, then melt together. There is a funny and instructive YouTube video on the subject by AVE.
I had a costly and unintended demonstration of friction welding in my workshop yesterday. I was drilling multiple small holes in the 2mm thick sides of the model Armstrong cannon, when, somehow, I activated the Z axis downward in fast motion. Probably I miskeyed G0 instead of G1.
The hole was drilled in a fraction of a second and the chuck continued downward. My reflexes are not TOO bad, but by the time I hit the big red button, the bottom of the drill chuck was grinding into and bending the workpiece. Which was glowing red hot!
“Oh Dear”! (Or something along those lines.)
I could tell at a glance that the workpiece had been destroyed. I had a spare piece, so it was going to cost some time to repeat the work already spent on the part, probably at least a day.
But that was only the beginning.
I backed off the quill, and tried to remove the workpiece from the of the chuck. It would not budge, so I released the 2mm drill bit (actually a carbide end mill) from the chuck. Well, I tried, but the chuck key would not rotate. The chuck was frozen solid. So I went and had a cup of coffee.
On return, it was apparent that the workpiece was welded to the end of the chuck, and the chuck jaws were welded together at the tips.
So, I released the chuck and its arbor from the mill, and broke off the workpiece from the chuck with a hammer. The weld and the drill bit broke. But the jaws of the chuck were still welded together.
You might recall that I had accidentally destroyed an expensive Japanese chuck some months back, and this one was its “temporary” replacement. Obviously I will need to buy a replacement this time, but I am in the middle of my cannon build, and want to get on with it. What to do?
On close inspection the weld between the jaws stopped about 3mm from the jaw tips. It involved the surfaces between the jaws and the still present carbide drill shank, and the sides of the jaws. So I ground about 3mm off the ends the jaws until they started to move. Then used a tiny grinding wheel in my Dremel to remove most of the weld between the sides of the jaws. At this stage the chuck is looking very ugly, but it works in a fashion, and I was able to resume my drilling. Very carefully.
I did straighten the bent workpiece, but it is RS. I spent the remainder of the day using my spare workpiece, repeating the lost work. No photos of the damage. I was not in the mood.
These are the sides of the second carriage. For this one I am drilling the holes in both pieces simultaneously, by clamping, and then bolting them together. Pretty obviously a better method. Sometimes I am slow learner. But I do try to not make the same mistake more than 3 times in a row.
The “B” carriage on the left, and work to date on the “A” carriage on the right. The bolts will eventually be replaced with rivets.
BTW, I have de-monetised this blog. You should not see any more advertisements. I noted that the income from the ads from the one post on which they appeared, was one cent. Yep. One cent. If I had monetised the site from its beginning, 6 years ago, I would have earned approximately $AUD6 dollars. Nuf said.
Meanwhile, I discovered some more videos from posts 5-6 years ago. I have deleted the videos. A pity about that, but it has created some more storage space and allows me to continue to post on the current plan.
If you have been following the build of the model Armstrong cannon, you might remember that most of the steel panels for the carriage were laser cut a few months ago. In the past few days I have been drilling dozens of 2mm holes, ready for final riveting. Meanwhile the parts are held together with 2mm bolts and nuts. I expect that the rivets will not be installed until I can see that everything fits and works as it should.
Only a few fasteners so far, but it is surprisingly rigid.
The angle iron is cut from the corners of rectangular section tube with 2mm wall thickness. It does require some more finishing and rounding off, but the scale is accurate. The big hole is to allow the hydraulic recoil tube to be inserted. The recoil cylinder will be 18mm diameter.
SWMBO’s comment…. “It looks like it is made from Meccano”. I guess that there are a lot of holes.
Meanwhile I have discovered an excellent reference source, published in 1879. It is a free book, available online at Google Books. “Treatise on the Construction and Manufacture of Ordnance in the British Service”. 517 pages. Original price 9 shillings. It is full of gems for the cannon modeller. As an example, this is a drawing of the sights on the 64 pounder RML converted to 80 pounder. You will see that the barrel shape is different from the one which I am modelling, which is a mark 3. But it is probable that the sights remained the same as those pictured. A great find, with enough detail for me to scale down and model.
Note that the sight on the right is not vertical, but sloped at approximately 2º. That is to compensate for the slight deflection of the projectile to the right, caused by the rifling.
From the same book, a detailed description of the Vent / touch hole / ignition hole. It was NOT just a simple hole drilled into the barrel, but a copper cylinder which was threaded into the barrel. The touch hole was drilled through the copper. The reason for this was that the touch hole gradually became bigger with use, and needed replacement after a certain number of firings. It also allowed repair of the touch hole if the gun was “spiked” by the opposition, but that was a major exercise which required specialist knowledge and tools, and a return to the factory or one of the 5 workshops listed above.
Geelong is not yet in total lockdown, and the weather was beautiful sunny and cool. And, the Flagstaff Hill Maritime Museum website indicated that it was again open! So I grabbed my camera, jumped in my car , and had a very pleasant 2.5 hour drive to Warrrrrnambool.
Out the front, I spotted this…
It is a 68 pounder, smooth bore muzzle loader, not an Armstrong, but VERY similar. But what excited me, was that it is on its ORIGINAL teak wood chassis. Original chassis’ like this are incredibly rare. The barrel date is 1861.
My Armstrong cannon would have been mounted on a wooden chassis like this. The wheels are almost identical to the Armstrong chassis wheels.
Then I entered the museum, and asked where the Armstrong cannons were. The very pleasant lass directed me to The Battery . The museum itself is really interesting, with wonderful relics from the tragically wrecked “Loch Ard” and superb ship models, sextants, octants, clocks, a fabulous Minton porcelain peacock raised from the Loch Ard. And heaps of other fascinating items.
But I was heading to the Armstrongs…
There are two of them. 80 pounders, identical to the one which I am modelling. And they have parts which are missing on the ones which I had originally measured and photographed. One item is the big wheel seen in the photo, which winds the cannon carriage on the sloped chassis, to its loading and firing positions. It is almost 3′ / 1 meter in diameter. The handles and rear platform are also in good shape.
And a comment about the black paint. The cannons on HMS Warrior, of similar vintage, were also painted black. So it is tempting to accept that as the original colour of the Warrrrnambool and Port Fairy Armstrongs. But look at the colour of this Armstrong (Singapore or Hong Kong, can’t remember).. the barrel is white, and the chassis a bluish grey.
and this one… Portland Victoria I think.
It seems that in hot climates, black was not universal, at least for the carriage and chassis. But I digress. Back to the Warrnambool Armstrong…
This was the other item which I really wanted to measure and photograph…
It is the brass, or bronze, (gunmetal, I discovered from one of my references) quadrant shaped protractor, which measures to a quarter of a degree, the elevation/depression of the barrel. It had been broken off, probably stolen, from the Port Fairy cannons.
I spent 3 hours crawling over and under the cannon.
The manager of the museum casually wandered past, and started up a conversation, and gave me permission to take a rubbing of the VR crest on the barrel. She seemed very interested in my project, and even suggested that I should join the cannon maintenance and firing volunteer group. Maybe, when the virus has gone…..
I took 90 photos, and multiple measurements. This time I had some calipers. A beautiful day. No whales seen, to my regret.
When doing my aluminium castings for the model Armstrong cannon, I noticed that the objects in the wax/PLA tree which were closest to the funnel (i.e. the topmost ones) were the ones which were most likely to have significant deficits, and I wondered whether the pressure of the molten metal at that level was the problem. The objects at the bottom of the tree were most likely to be successful.
Well, my friend Stuart Tankard is working on a positive pressure system, and I am working out a negative pressure system, to increase the pressure at the higher levels within the tree.
An interesting number is that for every 1″ / 25.4mm increase in the head of molten aluminium, the increase in pressure forcing the molten aluminium into the casting voids, is only 0.1 psi!!! Bronze, being much more dense (x3 – x4) would be less problematic, but still less than 1psi.
Some casters use a centrifugal system to increase the pressure on the molten aluminium. Frankly, that idea frightens the shit out of me. One episode of molten metal flying around my workshop was enough.
Stuart T is working on a positive pressure system, using approximately 5psi on the melt, to force it into the tree spaces, and he is well along the path of manufacturing the hardware to accomplish that.
I am inclined to use negative pressure to suck the melt down. I already have a vacuum pump, and I think that it might be easier to seal the hot steel cylinder to the silicon gasket which is required. There is a YouTube video on the subject.
(oops. I pasted the wrong VOG video. The one below is the intended one.)
I have ordered some 3mm thick Silicone sheet.
VOG, in the above video, allows the surface of his casting cylinder to cool to 100ºc before pouring the aluminium melt, so the silicone gasket does not burst into flame, and he has had some excellent results. It is casting heresy, and he should be burnt at the stake. But if it works…. hey?! (maybe the core of the casting cylinder is still closer to the molten aluminium temperature of 710ºc?).
So that is the path which I am following. Not exactly. But using the principle. Watch this space for my results.
Actually, molten bronze is my next pour. I doubt that it will require vacuum or pressure.
I needed to machine some of the aluminium castings which I had made for the cannon chassis. They were too high by 1-2mm. But, the flanges were delicate and thin walled, and although the ends were flat and roughly parallel, they were not actually parallel. I wanted to use my most rigid and precise lathe, which is the Colchester Master 2500. But the bore on the chuck was greater than the diameter of the part which I was turning.
So this is the setup. A chuck in a chuck.
The Colchester 3 jaw is 200mm diameter, and it neatly holds a 80mm chuck off my Boxford TCL125 CNC lathe, which holds the part. It is a centre column from the scale model Armstrong gun which I am currently assembling/making. It is a bit irregular, with thin 2mm flanges and fins. I really did not want to damage it, but it needed 1-2mm trimmed from its height.
So, I held the part in the 80mm 3 jaw, centre drilled it, and supported it in the 3 jaw and the tailstock. It worked well. No disasters.
I machined the three castings which I had made. And reversed them to machine the bases. The setup worked well. I need only 2 of these, and could use any of them. The machining did reveal some porosity of the castings, but overall I am quite pleased with the end result.
p.s. You might notice some advertisements in my posts from now on. Unfortunately I am at my storage limit on my current WordPress plan, despite deleting virtually all embedded videos, and placing the main ones on YouTube. I am facing the prospect of either deleting old posts, or increasing my WordPress payment plan to a business plan, which is substantially more expensive. I have decided to see if monetising the site will cover the cost of upgrading to a business plan. I do hope that the ads will not be too intrusive. Let me know what you think.
The assembly of my Armstrong cannon is progressing more slowly than I anticipated. No excuses. Just lots of holes to drill in precise positions, parts to turn and mill. And my workshop sessions have become shorter in the winter cold. Not that I mind the cold. I just light my workshop wood fire to remove the chill.
Today I have been making the wheels for the chassis.
Not a great photo. It shows a front wheel, 33mm diameter, turned from stainless steel. No axle yet.
And a rear wheel, 50mm diameter. Yet to have the track groove turned into the periphery.
I thought that the wheels would be easy to make. Just a bit of basic turning to size and form turning for the track groove and decorative relief on the faces. But as usual, I used whatever material I had on hand in the size. In this case stainless steel. It looks great when turned, but does work harden quickly, causing tooling problems. Parting off, through 50mm of hardened stainless steel is not much fun. In the end I used the band saw for parting, then tidied up the ends on the lathe.
Yesterday I spent some time with 600 grit emery paper on the barrel. A bit more elbow grease is required, but I took some pics of the progress….
From the left, the sighting line called the “line of metal”. There will be a corresponding line on the muzzle. Next is the weight of the barrel in hundredweight. 81cwt = 4 imperial tons plus one cwt plus 2/4ths of a cwt plus zero pounds. One hundredweight = 112 lbs, so this barrel weighs 9128lb / 4140kg. The arrows indicate that the barrel has been “proofed” and accepted for service and also possibly mark the end of bore. The dot would be where the “vent” would be located (the ignition or touch hole) usually about half way along the powder cartridge. Then the reigning monarch’s cypher. In this case, Queen Victoria, with her motto, that of the Order of the Garter. HONI SOIT QUI MAL Y PENSE. The translation from French is “Shame to him who thinks ill of it” (“it” being the Order of the Garter)
The Royal Gun Factory number of this barrel, and axis lines. One reference stated that they mark the centre of gravity of the barrel, but according to my assessment, the COG is well behind this point.
The other trunnion marks are yet to be lasered. Maybe late next week.
I am delighted with the quality of the laser “engraving”. It is sharp, crisp and finely detailed. Again, thanks to Stuart Tankard for the use of his laser, and for operating it.
The earliest cast cannon barrels were cast in one piece, and the trunnions were included in the casting.
By 1866 however, large barrels were made from 4 or more separate pieces, which were heat shrunk together, and additionally forge welded together.
The following information comes from “Naval Gunnery” by Captain H. Garbett, published in 1897.
The diagram is of a 64lb Armstrong rifled muzzle loader. The 80 lb muzzle loader, which I am modelling, was very similar to, and based on the 64lb gun, except that the diameters of the sections were larger, giving greater wall thickness.
The “A” tube, containing the bore, was made from best quality forged steel, in one piece, although earlier models used the “coil” method described below, and earlier than that it was wrought iron. It was permanently closed at the breech, but in slightly later models it was open, sealed with a copper disk which was held against the cascabel. The A tube was bored and rifled after assembly of all of the barrel pieces.
The “B” tube, or tapered chase was heat shrunk onto the “A” tube. It was a coil construction. (see below).
The “Breech Coil” had 3 components, plus a cascable which screwed into place with a deep, asymmetric thread. One of the components was the “trunnion ring”, which was welded to, and separated the other 2 components.
“COIL” TUBES.
When steel is forged into a strip, apparently it is strongest along its length due to the orientation of the crystalline structure. It was discovered that the strongest cannon barrels were made from long strips of forged iron or steel (up to 200 feet long), which were then wound around a mandrel, while red hot, forming a cylinder. The red hot coil was then hammer welded into a solid cylindrical mass, with most of the steel crystals aligned circumferentially. It was then machined into its final shape, with allowance for final heat shrinkage onto its mates.
The “TRUNNION RING”.
The trunnion ring was forged from a single billet of steel. Two holes were punched through the red hot billet, expanding the sides. Further hammering shaped the trunnions from the lateral expansions. The final shape was then machined.
The three breech pieces were forge welded together, and heat shrunk onto the “A” tube and the “B” tube. I could not discover the construction sequence of welding/shrinking these components.
This post is to correct an earlier post about the trunnions in the Armstrong cannon construction, in which I stated that the trunnions were heat shrunk into the barrel. The incorrect implication was that the trunnions were heat shrunk into holes in the barrel sides. My recent reading indicated that the “trunnion holes” method, which I used in my model, was NOT the method used in 1866. I am not losing sleep over this lack of authenticity in construction of my model. One of many compromises which are made when scale modelling.
This is the Queen Victoria emblem and motto on the original cannon at Port Fairy, Victoria.
The “Victoria Regina” emblem, and Order of the Garter slogan motto.
And this is what is now lasered onto the model cannon..
Pretty good, Hey? On the model, the emblem is 20x12mm. It was downloaded from the internet, edited with Corel draw, saved as a BMP file, and then lasered onto the steel model barrel. This is a photo of the emblem on the model cannon. The rectangular background will disappear with polishing.
It was made with a 30 watt fibre laser, driven by its owner, Stuart Tankard. It took about 30 minutes, 200 passes. Shows up my substandard turning.
Shows the emblem appearing after 100+ passes.
and this is an enlarged image of part the laser engraving.
I have some videos of the process, and I will make them available after some editing.
This was incredibly exciting. The model cannon requires more polishing, and colouring with a gun blacking chemical.
We also engraved the cannon weight, sight marks, and year of manufacture on the trunnions. I will post those photos when available.
The small cap screw bolts will be replaced with solid rivets.
The wheel axles are yet to be made and pinned. (the Philips head bolts will replaced with solid pins and washers, and held with taper pins.)
And just to remind you of the appearance I am aiming for…
I do wonder about the original colour of these 1866 cannons. The rusty iron colour has some attraction, but I would be certain that it is not original. So far I have had no luck finding out what the original colours were.
After 4 -6 weeks of making castings, and remaking them, and remaking them again, I have finally started drilling holes and bolting pieces together, in preparation for final riveting.
I ground a 2mm diameter end on my centre punch so I could transfer the cast holes on the brackets to the sides of the carriage for drilling. (using a toolpost grinder on my lathe to grind the center punch.)
Center popping
I could not resist pushing some parts together to visualise how the carriage will appear. 10 wheels per carriage to be made. This is the “B” carriage, on which I try out the techniques.
More riveting.
Using my new riveting gun, I inserted a lot more rivets on the “A” chassis…and I used a technique suggested by one of my readers…bearing in mind that my first riveting efforts marred the surface of the parent metal, and were generally rather irregular rather than neat.
Virtually NO surface dents, very regular, a big improvement. I had intended to polish out the machining swirls, but SWMBO said that they were appealing and interesting.
And the technique was this….
The rivets are inserted 5-10 at a time, then the heads are covered with tape. Duct tape in this case. The work is then turned over, and the rivets do not fall out.
Each rivet head is centered over the anvil, and the pneumatic gun is used with the snap on the other end. The tape stops the rivets from falling out, and also protects the parent metal from the snaps. I experienced virtually no parent metal bruising. And was VERY fast. A major improvement. Many thanks Timothy G!
If you want to watch a video of a model cannon being fired, try YouTube. Or you could watch the following video, sent to me by one of my readers. This is a slightly larger scale than my model, and a breech loader. Superbly built. Click on the arrow to watch it.
When anyone finds out that I am building a model cannon, the inevitable question arises “are you going to fire it?”
Up until recently my answer was “no”, because, 1. I do not have a shooter’s licence, 2. I did not intend to register the cannon and 3. Australia’s gun laws which I support, are strict and policed.
If a model cannon is capable of being fired, it must be registered. As an owner built gun, it would have to be “proved”, i.e. be inspected by a gun expert, and have some proving shots with powder alone, powder doubled alone, powder plus shot, double powder plus shot, and finally double powder plus double shot. Then the gun is certified for the particular weight of powder plus shot. I think that I got that sequence right. It was explained to me by a gun testing expert recently.
For a model cannon not required to be registered it must be incapable of being fired. For one such such as I am building, a muzzle loading, black powder cannon, that would mean not drilling the touch hole. In my case I could have the appearance of a touch hole, by making a dot at the site, but no drilling.
To investigate the situation, I have checked the Victorian Government website, spoken to police, and spoken to a firearms safety course instructor. I also visited a shooting range where a blackpowder gun club was having a target shoot. Members were shooting black powder guns and rifles at targets 50-100 meters distant.
About 50 years ago I was in the Citizens Military Forces, a university infantry company, and had instruction and practice in using a 7.62mm SLR, an F7 submachine gun, and an M60 machine gun.
My point is that the black powder guns were VERY loud. Painfully loud in fact, until ear plugs were fitted. Substantially louder than I remembered SLR’s, F7’s or M60’s. But maybe I have just forgotten. And the blackpowder shots were accompanied by a gout of flame, and a large puff of smoke. Spectacular, in fact.
Then, under the close supervision of a gun owner, I fired a black powder hunting rifle myself. It was loaded by the owner, using a ram rod for the charge, and a mallet then ram rod for the ball. 2 triggers. The first was a heavy pull to ready the shot. The second was a hair trigger to fire it. And hair trigger it was. Just a touch and it fired. Despite the BANG, some fire and smoke, and the instantaneous puff of dirt where I had aimed, the recoil was minimal, more of a firm push against the shoulder. It was an interesting and exciting experience. Less smoke and flame than the other blackpowder guns nearby, but maybe being a hunting gun, he had used a more modern powder. The following short video shows my son in law taking instruction.
I have put in an application for the firearms safety course which is supervised by the Victorian Police. Then there is a 2 part multi choice examination, with no incorrect answers permitted on critical questions, and 18/20 (I think) for the rest. If passed, there is a criminal history check, and references required. Then a compulsory 4 week wait.
I will get the shooter’s licence, to keep my options open, but have not yet decided about registering the model cannon. It would be nice to have a video of it being fired, for this blog, but it is very likely that it would be a once only event. My interest in the cannon is its historical associations, and the technology, plus the challenges of building it.
If the cannon is capable of being fired, it would have to be registered indefinitely, and the owner would need a shooters licence. After all of the time and effort in its research and construction I would hope that someone in my family would eventually own it, so I am thinking that I will not make a touch hole, and make it incapable of being fired. Another possibility which I will explore, is to register the cannon, make a video, then make it incapable of being fired by partly filling the bore and touch hole with molten metal then deregistering it.
For some reason which I do not really understand, my youngest daughter has become interested in my metal casting activities.
First she watched me do a molten aluminium pour.
Then she rang me a day or two later and asked if she could have a go. She really wanted to do it in brass or bronze, but as a relative beginner myself, and with only one episode of molten brass, and that one did not go so well, I demurred, and said that her first effort would have to be in aluminium.
So I prepared 3 flasks, printing the plastic parts, and gluing them into a wax tree, then slowly heating the flasks in the potters oven, up to 750ºc over 8 hours. Then lowered the oven temperature to the pouring temp of 710ºc. And preparing the aluminium melt at 710ºc.
When Eleanor arrived, we had a couple of practice runs with flasks full of sand, so she could get used to the weights and handling the tongs, and the various movements while wearing the protective gear.
Then the pour. This is Eleanor’s video of the event.
I admit to some substantial reservations about this exercise, but Eleanor listens carefully, asks intelligent penetrating questions, and follows instructions precisely. Full marks.
In order to increase the head pressure of molten aluminium during my casting pours, I increased the height of the casting cylinder to 250mm (previously 100 to 150mm).
That meant that the weight of the casting investment mix increased to 5.25kg. per 250mm cylinder.
This was the result today, when I poured the investment mix, then moved the cylinder with the rubber cap at the bottom. It would have been OK if I had waited for the mixture to set. (about 20″).
The rubber end cap slipped off, the investment mixture came out, the 3D printed parts tree fell apart, and an horrendous mess resulted.
After a barrage of unprintable expressions, I hosed the 3D prints down (outside), and washed the cylinder and end cap (outside).
By then the mess on the bench and floor had set, so I was able to scoop most of it up with a BBQ spatula. Then multiple wipe downs to get the very fine powder off the surfaces.
I still wanted to prepare the moulding cylinder(s), and for some reason I had lost my desire to use the 250mm cylinder, so I made 2 trees with the parts, and split them into two 150mm cylinders. Without further incident.
While waiting for the investment mixture to set, I did some further work on the previously cast parts.
Applying some JB Weld onto one of the cast rear wheel bracket and column assemblies.
Today I attempted another aluminium casting session with trees that I had made 2 days ago. More wheel forks, and barrel trolley brackets. 16 parts altogether.
And this time I installed air release vents, following my previous poor results, and at the suggestion of reader Rob R.
I also made some 50mm extensions of the pouring funnel, to increase the head of melt pressure. The extensions were “add ons” rather than designed into the system, and the molten aluminium leaked between the extension and the main flask with the tree, so I doubt that they were very effective.
BUT! Of the 16 parts on the trees, 14 were good to excellent, and only 2 showed any voids, and I assess one of those as repairable. So, 15/16 is very pleasing. I feel that I am closer to getting good results every time, if I can make an effective system of increasing the delivery pressure of the molten aluminium.
These are the extension pieces to the funnels on the investment flasks. The shape was made with the plastic funnel. If I had positioned them before the investment plaster had set hard they might have worked better, but as they just sat on top of the already hardened plaster, the join leaked molten aluminium rather badly. I have a different system in mind for my next pour.
Previous failures were cut up and thrown into the melt.
See the tiny silver dots surrounding the central funnel. That proves that the air vents functioned as intended.
The aluminium trees. Not very pretty, but delightful to see. 10 parts on the top one, 6 on the other. It is odd to see the wax spaghetti turn into aluminium spaghetti. I will separate the parts tomorrow.
And while the investment burnout and baking was proceeding, I worked on previously cast parts.
The centre columns have beep painted with etch primer. A little more filling required, then I will use the best 2 on the models. The 2 bracket and column assemblies on the right were initially considered unusable due to large voids, but I used some aluminium solder to fill the defects, and they might possibly be OK. The 2 on the left just need some tidying, machining removal of melt tubes, and minimal filling.
I will probably remake this one, but will continue to salvage it and see how well it comes up. Note the solder fill on the RHS. That will not be seen on the model.
One more melt and pour, and that should be the last of the castings made for the model Armstrong cannons. It has been a challenge, and lots to learn, but very interesting and very satisfying.
Finally for today’s post… I noticed some black marks on the normally pristine white wall above the casting bench. They extend about 4 meters above the floor. Do you know what they are? The paint has been melted off the wall by bits of flying molten brass, resulting from the steam explosion 2 days ago!
Many thanks to Rob R for his spot on suggestion about the air vents.
Today I received by mail 2 new crucibles for my furnace, so I tried a melt of brass.
The source of the brass was machining offcuts, machining failures (quite a few of them), and machining swarf. The swarf was not very clean, probably containing some aluminium, cutting oil, dirt and grunge.
It was an interesting experience.
Firstly, the temperature had to increase to 1000ºc. Later increased to 1050ºc. It is very hot. And the impurities came off as smelly fumes, and dross.
But, I poured some ingots.
And I made another remelt. And later remembered something which I had read somewhere….. molten metal and water is dangerous.
After making a few brass ingots, and quenching the moulds so I could remove the ingots, I proceeded to another brass melt.
When I poured the molten brass into the mould, IT EXPLODED!
IDIOT!!!!
FU**ING IDIOT!!!
I had caused a steam explosion. Probably the mould was still damp. And when the molten brass entered the mould, it EXPLODED. I kid you not. It went BANG. Luckily, none hit me, but some of the molten brass had landed up to 2 meters away.
OK. Lesson learned. Molten metal must be treated carefully, with respect. And NEVER put it in a container which is not thoroughly dry.
And after inspecting those brass ingots, I will never try to melt dirty brass, or any other dirty metals.
Meanwhile, preparing for another aluminium pour.
Here is the next tree. You might note that there is a spaghetti appearance of wax tubes added to the tree, to allow efflux of air from the cavities, as the melt enter them.
Next aluminium pour on Thursday. Fingers crossed. Stay tuned.
This video was taken and edited by my daughter Eleanor. I was doing an aluminium pour of some parts for the Armstrong RML cannon, explaining the process to her. I was hardly aware that she was videoing, so the interaction is conversational.
Although the pour was not a success because none of the parts were good enough to use, it does show the process as seen by someone who previously knew nothing about it.
There is also a 20 minute video of the whole process which I will add to this post when it is available.
Reader Rob has suggested that the positions of the defects suggests that air entrapment is the cause of the voids and that the fix is to position some vents at the positions at risk. I will try that with my next pour. Thanks Rob.
Here is the 22 minute video. Just as recorded. Not planned or edited.
One definition of stupidity is repeating a set of actions and expecting a different outcome.
Well, after my partly successful first molten metal pour, I repeated the same steps, (with some minor corrections), and hoping for a more successful result.
The day was entertaining, with one of my daughters videoing the exercise. But this was the result…..
The aluminium melt has not properly filled the cavities at the top (nearest the funnel). The bottom cavities have filled nicely, with good definition of the printing details.
The second flask with the same result.
My daughter found the exercise very interesting, particularly the pour and the boiling out of the investment material. But she was a bit disappointed that the end result was not better.
So, I am considering how to change the process.
I believe that I need to increase the filling pressure in the upper half of the flasks.
Possible methods:
Install a vacuum system for the melt pour
Use a vertical extension for the melt funnel, to increase the height of the column
Increase the diameter of the funnel tube
Increase the number of the funnel tubes
Don’t place tree branches close to the funnel
I had previously considered 1. as recommended on YouTube by several contributors.
The investment powder is a significant cost, so I would prefer to use as much of the volume of the flask as possible, which makes 5. an unattractive proposition.
There are difficulties with instituting 2. but I am thinking about this one.
And possibility 6, is to try bronze or brass, which has a much greater density, and probably less viscosity than aluminium. I am waiting for some more furnace graphite crucibles to arrive before I can try this one.
My family is vaguely interested in the stuff which I make. Engines, traction engines, cannons etc. But I doubt that any of them read these posts. The grandchildren like the steam engines, particularly the 3″ traction engine.
But, the molten metal casting has struck a chord in the youngest daughter, and tomorrow, when I do my second metal pour, she is coming to watch! At least I will have someone to hold the video camera.
So I prepared 3 trees, and poured the investment material for 2. I took some pics but forgot to bring the camera home.
Also, I am conducting an experiment.
I know that my early 3D prints were too porous, and allowed the investment material to penetrate the the moulds.
Tomorrow I am still using the original models which I know are too porous, so I am trying something.
I have covered the porous surfaces with super glue to try and seal them.
So, watch tomorrow to see if this experiment looks promising.
Yesterday I made some cast aluminium parts for the model 1:10 Armstrong RML cannon. It was the first time I had done lost PLA casting, and seeing the castings emerg from the investment mixture was thrilling.
Today I had a closer look at the parts, band sawed them from the trees, and tidied them up with some belt sanding and filing.
There were 3 central columns. In each case the vertical side flanges came out almost perfectly, but the bases contained some voids.
The undersides of the bases shows that the voids match the internal structure of the original 3D print. This indicates to me that the fault arises from the 3D print, not from the molten metal pour. Those columns were among the first 3D printing that I had done, and I remember that the surface layers were only 3 layers thick. Since then I print substantially thicker surface layers, which I believe are more water tight, and less likely to let the investment material leak into the structure of the print.
Although they look very ordinary, I will fill these voids with JB Weld, then paint them with automotive filler primer, then the final paint coat(s). If they are still substandard I will start again with new 3D prints,
I also poured 6 wheel forks. 2 were so bad that I have melted them down into ingots for re-use. The other 4 looked resurrectable. Unfortunately I had a mishap when bandsawing the parts from the tree. The tree was flung across the workshop, and one of the forks snapped. Of course it was the best one.
So 3 of the 6 forks were put into the re-melt, and I did some tidying up on the other 3.
This lot was remelted into an ingot for future re-use.
The 3 on the left after some tidying. Same problem with the voids in one base, but structurally OK and can be fixed. I scrapped the one on the right. I might eventually remake them all.
So, although I ended up with 6 use-able parts out of 9 made, and most of those require filling, I am still reasonably happy with this first attempt. I think that the 3D prints were the weak link in the chain, and with that assessment I will try another casting run in a few days.
Meanwhile, back home I printed a Tyrannosaurus Rex. I think that it is my best 3D print so far. It is 250mm long, and the level of detail is excellent, even the vestigial arms are intact.
About the colour. No one has any idea what the original T Rex skin colour was. So even this red is possible (but unlikely). Nor do the scientists know what noises the T Rex made. Could have been a reptilian hiss, or a roar, or a porcine grunt. Whatever, I am glad to never hear it.
50% preparation of the PLA originals, 45% preparation of the investment, and 5% management of the pour. You have seen making the trees with the PLA originals. Today I melted metal, poured, and held my breath. First metal pour. I also made some videos, but the autofocus on the Panasonic LX100-2 is so crap (or maybe it was the operator who was more focussed on the metal pour), that I have scrapped the videos. But some stills are OK, as you will see.
I purchased an ingot of casting aluminium, and bandsawed some pieces to fit into my melting crucible. Then I washed and wirebrushed the pieces in hot detergent. There was minimal dross in the melt, so this step was worthwhile, and the ingots must have been fairly free of contaminants.
Next, was measuring the investment powder and water, using kitchen electronic scales. After mixing there is a 10 minute window for thorough mixing, removal of air bubbles in the vacuum chamber, and pouring into the investment moulds, which had been prepared beforehand. (see last post).
10 minutes sounded like lots of time, but this was a real time and motion study, having everything ready, with no delays. But when I saw the clouds of silica dust I remembered that I should be wearing a mask. So, quick dash, pull on mask, find hearing aids dislodged by the mask, and back to mixing the investment mixture.
Then, 1.5 hours for the moulds to set hard, and remove the rubber caps with the pouring funnels built in. That exposes the bottom of the wax trees. The hose clamps were to assist security of handling the steel cylinders with flask forceps. Next time I will position them closer to the funnel end.
The moulds, after removal of the rubber ends, are placed in the investment oven, for 4 hours at 250ºc, 2 hours at 400c, and 2+hours at 750ºc. The wax and PLA plastic is burnt out and the investment powder sets really hard. The steel cylinder is red hot. The wax and PLA comes out as smoke, with no other remnants seen.
The aluminium ingots are melted at 710ºC, and any dross is scooped off the surface.
Meanwhile, I have placed a sheet of cement sheet on the floor, a tray of dry sand, and moulds for any excess aluminium melt. There is a bucket of cold water ready.
when the mould has been at 750ºc for at least an hour, and the aluminium has melted at 710ºc, the mloten metal is poured into the moulds, which have been removed from the investment oven. Made a video, but not showing because very poor quality. After about 30 minutes, the still very hot mould is plunged into cold water, which blows out much of the investment.
And here is the result……
These are the rear wheel forks. I need 4. 2 were unusable, and will be remelted. 4 are good to OK, and after some filling with JB Weld, and painting, will be fine. The 2 failed forks were those closest to the funnel. Not sure why.
These are the centre columns. I need 2. All 3 are repairable. One is very good. Again, the top one, closest to the funnel, (RHS) will be remelted. I did not vacuum the melt into the moulds, and the weight of melt is lowest at that level. (maybe the cause for the poor result there?)
so, when I had a closer look at home, none of the pieces are perfect, but they are not too bad. For a first run, I am really pleased.
With many thanks to Stuart Tankard for his advice and encouragement.
The adequately sized vacuum chamber arrived today, much more quickly than I expected. Initially it would not seal and I could see no holes or leaks. But when I removed the silicon gasket I found a small silicon flake which was the problem. Thorough cleaning, and all was well.
The 1/4hp vacuum pump on the left. The new 5 gallon chamber hooked up. And the too small 3 gallon chamber on the right. I have an idea for using the smaller one, so will hang onto it.
With this arrival I am almost fully equipped to start casting. So today I built 2 trees.
The first tree has no branches, so it is more like a tree trunk. The red items are plastic models of the central pivot column on the Armstrong model gun. Glued together with wax which I melted with a soldering iron. (soddering iron for American readers). And attached to a wax stick which inserts into the rubber flask end at the bottom. The actual steel flask is behind.
And here is the “tree” trunk in position inside the flask, ready for the investment plaster to be poured around it. After pouring it sits and sets for a couple of hours. Then after removal of the rubber end, about 8 hours in the kiln to melt out the plastic and wax. Then the molten metal pour.
This is the second “tree”. Wheel forks for the cannon chassis. Wax glued to the central wax tree trunk. The 4″ steel cylinder behind.
Preparing the moulds, and the metal pour will probably occupy about 10 hours, so I will need a totally free day. Maybe Thursday.
I am waiting for delivery of the 5 l vacuum chamber so I can commence casting parts for my 1:10 Armstrong cannon. So today, I spent some workshop time riveting the chassis of the 1:10 Armstrong 80lb muzzle loading rifled cannon model.
I am a total novice as far as solid riveting goes. The following photos will prove that fact.
I am holding a new Taiwanese riveting gun. The girder into which I have just inserted almost 100 copper 2mm rivets is resting on the vice. The anvil is clamped into the vice. The snap (home made) is in the gun.
I have marked the surface of the girder with the anvil and snap. Doesn’t look good, but I am hoping that it will be acceptable after painting.
I painted the inside of one girder with layout paint just to see if the crappy riveting will be acceptable. Still considering that question.
A staged photo of rivet insertion.
And just to lighten this post, yesterday I had a visit from my grandchildren, 2/3 daughters, sons in law, and SWMBO at my workshop.
So I fired up the Fowler 3″ traction engine and gave the kids a demo of filling the boiler with water, lighting the furnace, a discussion about the nature of coal, and a ride.
Despite the wintery weather, it was a very happy afternoon. Audrey 4, Edward 4, Charlie 4, and John 7. And John 70. We have had an unusually wet autumn, hence the green grass. No tigers seen.
Setting up for casting molten metals into shapes for my model Armstrong cannon. Still getting ready.
Today I made some moulds for dealing with any left over metal melt. Not a big deal, but it does have to be done before the first melt. No point realising that there is nowhere to put the left over aluminium or bronze during the pour. It has to go somewhere.
So today I made some ingot moulds, in readiness.
The ends of the moulds are sloped to allow easy ejection of solidified aluminium or bronze.
4 ingot moulds. Made from 40mm ID thick wall pipe, with long handles. The diameter of my crucible is 48mm ID, so any ingots made should fit into my crucible later for remelting.
It seems a long time since I have done any welding, and the welding of these items was pretty ordinary. But the joins seem water tight, so hopefully they will be OK.
Today I fired up the casting oven, to 850ºC, and the load was some ordinary food tins. They are the correct diameter for investment moulds. I wanted to see if the tins would cope with these temperatures. (after removing labels of course).
3 ordinary food tins, at 850ºC.
It became apparent, that the tin joins were welded not soldered. And the inside and outsides of the tins were covered with some sort of paint or plastic, because it flaked off. But the metal cans remained intact. Admittedly, when hot they were VERY soft, but when cooled they retained their shape, and were quite stiff. I would be prepared to try these for single use moulding projects.
I have realised that my investment plaster mixing bowl is too big for the vacuum chamber which I had bought. So I have ordered another vacuum chamber, and waiting for it to arrive before starting a mix. I am using the delay to gather items like the ingot moulds above.
It will probably be another couple of weeks before I am ready to cast. Meanwhile my 2mm rivets have arrived at last, so I will get back to the riveting.
I made this 1:10 scale model of the Turkish Bombard which currently resides in the Royal Armories Museum, Portsmouth, in 2016. I specify “currently” because I originally saw this cannon in 1979 at The Tower of London. And long before that it was used in Turkey, guarding the Dardanelles. Quite likely used in anger in 1805 against a British fleet, approximately 340 years after it was made for Sultan Mehmet “the conquerer”.
And I re-visited the original in May 2019. It seems like half a lifetime ago. Mainly I visited the UK to see the Trevithick dredger engine in the London Science Museum, but the Turkish bombard was the second reason. I could not find a photograph of the touch-hole in the bombard anywhere. And my requests to the museum went unanswered.
The original bombard in the Royal Armories Museum, Portsmouth, UK.
So, here is my photograph of the touch hole, in case anyone else is inclined to make a model. I guarantee that this is the only photo of the touch hole which you will find, with my hand anyway.
The Turkish bombard touch holeMy 1:10 scale model of the bombard. I still have not added the touch hole.The Arabic script around the muzzle. Not as good as in the original. But as good as I could manage in 2016.and the large thread between the barrel segments
So, I made this model, in wood, as a practice run, intending to make a bronze model eventually.
The reason for this post script is that I had a question from a reader about a remark which I had made in 2016. And I could not find my original photographs. So I took some more, as you have seen.
And……… very excited to announce that I now have a foundry setup, and could possibly make a bronze example of the bombard. But first I intend to obtain some casting skills, by making parts for my 1:10 Armstrong cannon.
I replaced the analogue controller with a digital type in the potter’s oven which I had recently purchased, and today my wiring was checked by an expert before we ran a test run. (thanks Stuart!) All good, up to 750ºC, which is enough for preparing the investment molds.
Here is a shot of the oven, and the metal melting furnace.
from the right, the melting furnace which should be adequate for 3kg of brass/bronze, and the investment oven. The oven might also be useful for metal tempering. Note the Hebel bricks behind the oven.
Hopefully, the first attempt at a casting session in a couple of days.
There are 3 major components of each wheel assembly, plus the wheel, axle, and king pin.
The wheels, axles and king pins are straight forward metal turning, but the other 3, the wheel bracket, the king pin post, and the chassis bracket, are castings in the original.
For my 1:10 model I am planning to cast the king pin column, and the wheel bracket. But I will fabricate the chassis brackets.
There is one chassis bracket for each of the 4 chassis wheels, and they are all different. Front different from rear, left and right hand versions. And each one has angles of 90º, 30º, 20º, 6º, 2º so the machining was quite a mental exercise. No major stuff ups though.
Here is the main component of the left hand rear chassis bracket, being held in position. It will be bolted on later, and have several flanges silver soldered to it. Those M2 cap screws will be replaced by rivets eventually.
Meanwhile, having decided to cast the king pin casing, and the wheel bracket, I spent many pleasant hours (or was it days?), drawing them. Then yesterday, I 3D printed an example of the king pin casings.
2.5 hours to print PLA examples of rear (left) and front king pin casings. I need to see the original cannon to check some details before committing to cast these in bronze. The PLA parts will disappear during during the casting process. (A pity. They are quite attractive No?) You can see why I chose not to machine them out of bar stock. 3 pin holes in the left hand print ? the result of not storing the PLA spool in a dehumidified container.
So, it might not look like several days of computer and workshop time, but that is how long it has taken.
In Australia we have had some easing of Covid-19 restrictions, but not opening of museums or historic collections of cannons. So I still cannot go to Warnambool (a 2.5 hour drive) to check details on their Armstrong 80 pounder rifled muzzle loader. Flagstaff Hill Maritime Museum does not answer their phone. Hmmm. Maybe I could climb the fence and sneak in…… but maybe not.
The steel chassis is virtually finished, although I am delaying inserting the final rivets which join the girders together, in case I need access to the individual girders for more machining or drilling.
The 2 chassis’ are not identical. Can you spot the differences? And still waiting for more rivets to arrive. The copper colour on the front one resulted from dipping it in well used sulphuric acid after some silver soldering.
Considering how to model these wheel assemblies…..
The front wheel assemblies
The rear wheel assemblies
The rear wheels and supports are larger than the front ones. But the top views are essentially the same. The wheels themselves present no difficulties. They will be turned from 50mm diameter steel rod. And the axles will be all identical.
But, those supports are complex, and will need to be silver soldered parts, or possibly cast from 3D printed lost PLA bronze or brass. Just drawing them was challenging.
This is a complex project, and the parts are complex.
Considering that the original cannon barrel was made in 1866, and the steel/iron chassis made approximately 20 years later (the original barrels were mounted in a wooden carriage), the standard of the workmanship in the originals is simply superb. Even at 1:10 scale, and using modern equipment including CNC machinery, I am struggling to match the standard of fitting steel pieces together so neatly. I am in awe of the original engineers.
(and by the way. Neil M, who very kindly loaned me the rivet gun which died, has loaned me a replacement gun. The replacement gun is a bit bigger, and more fierce. It requires more care in not overdoing the hammering, and bending the steel parts or producing “two-bobs” in the work piece. “Two-bobs” will be understood only by older Aussies? They are unintended dents in the workpiece produced by hammering.)
The strength and resistance to twisting and other movements of the Armstrong cannon is in the chassis. Specifically the design and strength of the longitudinal girders, AND the box section structure at the front of the chassis.
The box section has been a challenge in the 1:10 model. Actually, it has been a bit of a nightmare.
It has taken me 3 full day sessions to work out how to construct this assembly, to make the parts, to join them together, then a lot of filing to make the assembly fit the girders.
And, of course, the parts are riveted together, and I am a total novice at riveting.
So this is the result. Not totally finished and assembled, but getting there.
Again, I left my camera at the workshop. These are photos which I took with my phone.
The box section is an assembly of parts. The ends were silver soldered. The panels which show are steel, and will all eventually be riveted to the end sections. At this time, some joins are still just bolted and nutted.
This is the front of the chassis. The rivets look OK yes?
And the inside rivets were the first ones to be inserted. Mostly worked OK. They are copper, will eventually be painted the same colour as the girders.
And after the riveting, I have spent almost a full day of gentle and progressive filing to make the box section fit the girders. It all fitted beforehand. But after riveting, nothing fitted. All of that hammering clearly changed some of the dimensions. But, despite all of my pessimism, it all eventually fitted.
Now, I have another chassis to make.
Do I repeat the method, or maybe try something more efficient. Like making a solid block of brass or steel, shape the exterior to dimensions, then hollow the interior? Still pondering that one.
Part of the equation is that the riveting gun died. Not sure what happened. Maybe a blown O-ring? The final few rivets in the above pictures were hammered. My hammering is definitely not as neat as the rivet gun. I do have a rivet gun on order, but they are estimating an arrival date of the END OF JUNE! I cannot wait until then. And the faulty gun is not mine so I feel diffident about pulling it apart and maybe repairing it, maybe really screwing it up.
The last time that I cursed the virus I lost 25% of my readers, so I will just think it.
THE HUMAN SKELETON AS EVIDENCE FOR CONFLICT IN THE PAST
By Martin Smith
Hardcover. £25 RRP. Pen-and -Sword. UK.
This book was not a relaxing read.
The author, Dr Martin Smith, is a Biological Anthropologist with particular interests in prehistoric populations. He examines human remains, taking a forensic approach, to try to determine whether violence was the cause of death. Since ancient remains rarely consist of more than skeletons, soft tissue injuries are not evident. So, the violent causes of death where bones were not injured are not assessable, and the incidence of violent deaths is certainly underestimated.
Crushed skulls, decapitations, cut wounds in bone, shattered bones, remains of weapons such as arrow heads and or spear heads inside skeletal remains are all assessed as violent deaths. Evidence of bone healing is also taken into account.
The book is divided into eras, from the deep past, the Mesolithic, the Neolithic, the bronze age, the Romans, Medieval England, the high Middle Ages-Renaissance. It does not deal in detail with the twentieth century.
Although the descriptions are often shocking, some fascinating conclusions are reached. Human history, it appears, has always been violent. At least 10% of all deaths in the “stone age” were violent, usually as evidenced by skull fractures, and contradicting the traditional “peaceful primitives” view of the era. The incidence of violent deaths is highest in the lowest, worst nourished classes, in all societies. Wounds resulting from black powder firearms were often more severe than from modern guns. (to mention just a few examples.)
There are many illustrations, line drawings and maps in the 290 pages. The text is a pleasure to read, although, I confess, I had to take it in small doses.
Another really fascinating read from Pen and Sword.
After a fruitless 3-4 hours searching for my lost hearing aid, I decided to make a bit of progress on the Armstrong cannon chassis. At least I got the workshop floor swept clean for the first time since last winter. The tigers should be hibernating in this cold weather.
In the above photo you can see that the rear cross member, which I have named the “transom”, is now bolted into place, with 14 M2 bolts and nuts. Later these will be replaced with solid rivets. I reckon that I had about a 70% success rate of inserting the tiny M2 nuts. The other 30% are somewhere on my workshop floor… probably keeping the hearing aid company, wherever it is.
When those connections were made, ensuring that the upper girder surfaces were parallel, I filed the angle brackets flush with the girder surfaces. To ensure that the file did not scratch the girders, I rested the end of the file on a sheet of paper.
The next job is to make the front joining piece of the chassis. It is a box construction, so will be more complicated, but should make the chassis quite rigid.
It is a bummer having only one hearing aid. About $2000 to replace the lost one. I would have preferred to spend that sort of money on a tool. Or a good drone. But SWMBO is adamant.” get that hearing aid replaced!! ” (at least that is what I think that she said.)
Sorry, no photos with this one. As I was leaving my workshop I realised that I was missing one of my hearing aids. It was dusk, raining, and I spent almost an hour searching for it, but no luck. Then I forgot to bring my camera. So no photos. Big cleanup of the workshop in daylight tomorrow.
A half day in the workshop today. Finished silver soldering the chassis angle brackets, then fitted them, and secured them to the girders with bolts. In order to make sure that the brackets are correctly located for the drilling, I glued them with Super Glue initially.
The first half of the day was spent on the computer, working on Queen Victoria’s Royal cypher which is on the top surface of the cannon barrel.
The “VR is for Victoria Regina”. “Honi Soit Qui Mal Y Pense” is the motto of the Order of the Garter. It translates from the French as “Shamed be (the person) who thinks evil of it”.
It appears to have been machined into the barrel. On my model it will be about 12.5 x 20mm. My friend Stuart has a fibre laser which was used to permanently mark guidelines into 2 steel grinder rests (featured in earlier posts), and I am hoping that it will work similarly to put the cypher onto my model Armstrong cannon barrel. Another option would be to V carve the emblem, using V Carve Pro. Whichever method is used, I needed a bitmap file of the emblem. I found several with a Google Images search, but they were very low resolution. I should have made a rubbing of the cypher when I was at the originals at Port Fairy.
236×277 but I have spent some time with a drawing program (Corel Draw) tidying up the image, then converting it to vectors, suitable for V Carving. The laser can interpret a bitmap file.
The curve of the barrel must be negotiated during the lasering or V carving. Still considering options for that.
So, when the Covid restrictions are lifted, that will be one of the first visits. To Stuart and his laser. A practice run on some scrap pipe first.
Only a half day in the workshop today. Wednesday is my Model Engineering Society weekly “Zoom” meeting, and I would not miss that for quids.
But, I did get into my workshop after that. And this is what I made….
I am trying to make a bracket to join the side girders of the Armstrong RML cannon to what I will name the “transom”. The transom is the lump of steel joining the side girders at the back of the chassis.
“No big deal” you say? Well, that bracket has angles of 90º, 4º, 6º, and some indeterminate ones. And must sit flat with 2 pieces. And is a single piece of steel.
First I tried to bend a piece of 2mm steel.
Even though the bender is rated only for 1mm, it managed 2mm thick plate.
Plus some hammering in the vice…
…but machining all of those angles and distances was just too difficult…. This steel effort was just not up to scratch. Look at the gap under the bracket. Yuck!
I cut out some brass pieces, and used a vertical belt sander (the Radius Master), to get them to fit snugly…..
then cut some separate pieces to complete the brackets and secure the transom…..
checking the fit of the right angle piece…
then silver soldered the pieces together. The bits of steel are to keep the brass pieces in position during the soldering.
That is the angle bracket being held to the transom by my rather dirty fingers. But, it is all nice and tight, and will do the job. Rivet holes yet to be drilled. Soldered joint? I hear you ask? “As strong as the parent metal” I answer. One made. A bit of filing required. And 3 more to go. They will be painted the same colour as the girders eventually, so who will know that they are not steel. Just you. don’t tell, or else….
Not much happens in each workshop session. I am still a bit unsure whether I should only post when some significant progress has occurred, or whether the minute daily progress is enough. Whichever occurs depends on my mood. At the moment I am posting daily progress. If it is just too trivial and boring, well, hang in there. No doubt there will be big significant gaps in the future.
Today I thought about how I would assemble the chassis for the Armstrong cannon. And I decided to do some woodworking.
So, I machined a block of wood, exactly the size to separate the chassis girders.
Wood has an advantage over aluminium or steel. Apart from being cheap, it is slightly compressible. Here, I have accurately machined a block of wood, and by adjusting the tension in the G-cramps, I can adjust the distance between the girders to exactly what I want. And using the granite setup block to keep the upper girder surfaces exactly parallel.
Getting those girder surfaces exactly parallel, on a granite setup block.
Then I marked out one of the end pieces, filed out the girder flange recesses, and fitted it into place.
The end piece will eventually be riveted into place, using an angle bracket. The dented girder corner top right, occurred when I dropped the girder onto the workshop floor! Or maybe it was a Russian shell hit.
So, not much to show for a 6 hour workshop session, but actually, some decisions made. And more small steps.
And a BIG discovery! Another Internet search has shown some more of this exact cannon at Warnambool, Victoria. And from the few photos on the net, those Warnambool cannons are more complete than the ones which I measured at Port Fairy!
6 hours in the workshop today. I am constantly surprised at how little progress appears per session. Also surprised at how quickly the time passes.
I had left the external dimensions of the cannon chassis girders rectangular, to facilitate holding the items, while doing as many machining processes as possible with the rectangular shape. But today I bit the bullet, and made the final girder shape.
There is a 4º angle at each end, and a 6º slope along the bottom of each girder. Also, the top flange is 11.5mm wide, and the bottom flange is 14mm wide.
Setting up for the bottom 6º angle. The 4º ends had been machined before this.
The rivet holes are different at each end
The 4 girders are all looking good. Next to start making end pieces and brackets. I am still waiting for rivets to arrive, so the assembly will be bolted together initially.
“Dedicated to Naval History in the Nelson Era”, the fourth volume in this series contains 21 essays, richly illustrated, and clearly reflecting the fact that the authors are enthusiastic, knowledgeable and articulate about their subjects.
This is a book to be read from cover to cover. It has classy feel, the illustrations and maps are excellent, the topics interesting and eclectic within the period.
I particularly enjoyed the chapters “The Decaturs”, “Nelson Was an Irishman”, “Russians on the Tagus”, “Captain John Perkins” (the first black officer in the Royal Navy) and “The Carronade”. The last because this reviewer has a particular interest in carronades. If I might take the liberty of showing a personal item….
Photo 1 Model carronade made by the reviewer 2015
The essay by Anthony Bruce is the best description of the history of carronades which I have read. Particularly the descriptions of naval actions where carronades made a significant contribution.
I eagerly look forward to further volumes in this series.
Today I drilled the girders of the chassis under the Armstrong cannon. Each girder has 91 rivet holes. Later I will need to drill more for the gear shafts, and for the center pivot bar.
The holes are 2mm diameter.
The mill drill setup. Re- indicating the vices again took me about 45″.
Firstly all of the holes were center drilled, then drilled through. The rivet confirmed a nice sliding fit.
364 holes, through 5mm of steel done with one center drill, and one 2mm drill. That is pretty impressive IMO. More than 1.8 meters of steel with 2 drill bits. And using my olive oil and kerosene lubricant-coolant. And the bits still seem to be sharp.
Each girder took about 28″ to drill the 91 holes. CNC of course. It has been a while since I said it….. “I love CNC”.
There are quite a few pieces of angle iron in the Armstrong cannon. In the original they measure 95x95mm, and are about 15-16mm thick. Also, there is a definite radius between the 90º faces. At my 1:10 scale, the material becomes 9.5mm x 9.5mm, and about 1.5mm thick.
After considering various options, which included using extruded aluminium, and bending some sheet mild steel, I decided on the following solution….
I bought some offcuts of RHS (rectangular section) with 1.5mm steel thickness, and used a bandsaw and milling machine to produce the required dimensions in steel.
This is a piece of 50 x 25mm rectangular section steel which has been bandsawn in half, then the corners cut off to produce 10x10mm angle of the correct thickness. Sawn pieces on the right, ready to be tidied up on the mill. The bandsaw really takes only a 5/8″ wide blade, but that is a 1″ wide blade which I made up with a silver soldered join, and it works fine! Note the improvised wooden fence.
Firstly, on the subject of metalworking lubricants, I have previously mentioned my homemade mixture of kerosene and olive oil. And here is my favourite lubricant…..posing with the not quite finished cannon chassis girders…..
For this model cannon I need quite a few sheet metal parts. At 1:10 scale the final metal thickness is 2mm and 2.5mm. Having had a good experience with laser cutting the HSS cutters for the rifling tool, I decided to send an electronic file to the laser cutting firm, and see how the parts turned out. I decided to not include the rivet holes, thinking that the final positions might not be completely predictable. If all goes well I will probably include all of the holes in future orders.
I ordered enough parts for 2 cannons, and some spares for the inevitable stuff ups. (or should it be stuffs up?). If I do not use the spares I might offer them for sale later, along with my plans.
The accuracy and quality of the cuts seems excellent. All of the parts will require final fitting and drilling for rivets, shafts, etc. I was pleasantly surprised at the modest cost of these 30 parts.
So next I can start assembling the chassis. Lots of riveting. About 500 rivets per cannon. Another skill to be acquired. Fortunately for me, one of my model engineering club colleagues used to work in aircraft manufacturing, and he has spent a session teaching me the ins and outs of installing solid rivets. And loaned me a riveting gun suitable for the 2mm rivets which I have chosen. Thanks Neil!
The gun is about 40 years old but it works well. The snaps are all imperial, so I made one, and modified one to fit the metric 2mm size.
The blank snap in the ER collet is an unhardened punch blank. Here being drilled with a carbide ball nose end mill. Not exactly the right size, but with some fiddling I got it very close. Since I am intending to use copper rivets I will not harden the snap.
My initial riveting practice run in aluminium was a bit unimpressive…..
….but I did improve. These are almost up to scratch. In aluminium.
And finally for this post, I drilled some holes in the muzzle of the barrel. Do you know why they are there?
A staged photo, using the 3D printed barrel, to show the drilling setup.
Having made the decision to try to mill the girders from solid steel bar, I bought some 50x16mm bar and cut it into 400mm lengths.
Then milled it to 46.4 x 14mm, then used carbide end mills to form the girder profile. This process produced a large amount of hot, sharp chips, and took 2 full day sessions in the workshop. Each evening I spent about 30 minutes pulling bits of swarf from the soles of my boots with pliers.
And I discovered the limits of my milling machine. The 5hp spindle motor never hesitated. Nor did the axis AC servos. I did manage to chip the cutting edges of a 12mm carbide end mill when it dropped onto the milling table. And I blunted another one. Not sure how that happened. Maybe hit a hard bit in the steel. No, the limit of the machine was the ability of holding the end mills in the ER40 collet chuck. If I pushed the depth of cut or the feed rate too hard, the cutter would start to move in the chuck. I managed to ruin one work piece in discovering that fact.
There is virtually no distortion resulting from the milling. The apparent bend in the photo is photographic distortion.
The Vertex milling vices are within 0.02mm for height. I picked up the second vice cheaply on Ebay a couple of years ago, with this exact purpose in mind. (milling longish workpieces)
3 made. One to go. Plus the bottom 6º shape and the 4º ends. Each 4.5mm deep pocket takes about 25 minutes, at 300mm/min feed rate, 1.5mm depth of cut, 2700 rpm.
I should be able to finish the girder shapes tomorrow.
These milling marks are visible but very not finger tip palpable. Any suggestions for a good method of improving the finish?
Then to mark out the rivet positions, and insert about 100 rivets into each girder. In the model these will mostly be decorative. In the original they held the components of the girder together. Luckily for me, a fellow member of our model engineering society is a very experienced riveter, having worked in aircraft manufacturing, and he has offered to spend a session teaching me some basics. In the original cannons, the rivets are superbly neat, regular, and obsessively carefully laid out. I will try to do likewise.
I will start by making the main girders. At 1:10 scale they will be 400mm long, 11mm wide and 46mm deep. Some fabrication will be required.
Many rivets required. I will need to improve my riveting skills. One issue to be decided. Do I use copper (easy) or steel rivets (authentic)?. Whichever, they will be eventually painted the same colour as the girders.
And another decision. Your opinions invited. 2 methods for fabricating the girders.
TIG weld the flanges top and bottom (right). Or, (left) join 2 pieces of angle iron, then TIG weld the bottom flange. I don’t like the top groove to be filled. I do not really want to paint the surface that the carriage wheels roll along.
It is a very long time since I did any TIGging, so maybe some practice runs first…
And another option comes to mind…. just to machine the shapes out of solid bar. I think that I will try TIG first.
Later…. just remembered. I don’t have any TIG gas. Easter. Bum. OK. Back to square one. Maybe I will try to mill the shape from bar…..
On my “reject” barrel the silver soldering was problematic, and one trunnion was subsequently glued into place with Loctite 620. This proved to be so effective, clean, and controllable that I used the Loctite for the main barrel. The following video shows the Loctited trunnions being machined, and showing no signs of being dislodged.
It also shows a possibly dodgy but successful method of rounding the ends of the trunnions.
The finished trunnions and shoulders. Resting on a 3D printed platform which is quite handy.
Silver soldering the trunnions into the barrel and the squared blocks did not go well.
For a start, I did not know the composition of the steel of the barrel. The trunnions were/are silver steel, and the blocks were mild steel. So it is possible that I did not use the best flux.
And the barrel is quite hefty, so I knew that it would require a lot of heat to get it to temperature, and to keep it at soldering temperature. So I used a large oxy-propane torch, and heated it to dull red heat.
The steel pieces fluxed and wired together, ready for heating
It was a cool day, but the heat output from the red hot barrel was ferocious.
Soldered, but one side was not good, and a hammer blow dislodged it. Damn.
The good side, partially machined.
I dithered about how to deal with the faulty side. I was not enthusiastic about re-soldering it, expecting that the good side would fall apart.
So I cleaned up the pieces, and used high strength, high temperature, Loctite 620, to join the pieces. The machining will test the strength of the joins, so I will give it the full 24 hours before testing it. This is the “reject” barrel.
Still pondering how to join the trunnions of the “good” barrel (front). I will discuss it with my colleagues tomorrow when we have a Model Engineering Society meeting on “Zoom” video link. The 3D printed barrel at back is a handy “how it should look” example.
The 80lb Armstrong RML cannon trunnions were probably heat shrunk into the sides of the barrel. (WRONG! See post from July 2020. The construction of these barrels was much more complex than I had imagined. The trunnions were part of a forged ring which was heat shrunk then welded to the other components of the barrel). The squared off barrel sides would have been part of the original wound and welded steel rods, and machined to shape before the trunnions were inserted.
The hole above the trunnion is to hold one of the 4 sights.
For the 1:10 model I considered various construction methods. This is what I decided…
The 20mm diameter trunnion is fitted into a milled steel block, and the 2 pieces on each side are then silver soldered into prepared recesses in the barrel.
The the barrel is mounted in the CNC rotary table and tailstock. 15mm deep holes are drilled into the barrel….
and widened to 20mm diameter (drilled then milled)…… (for cutting fluid I use a mixture of olive oil and kerosene. It produces a lot of evaporated fluid but is very effective at keeping the job cool).
….then complete the recess. The bottom of the recess is 8mm clear of the bore.
Next step is to make the blocks, the trunnions, and silver solder them all together. Not entirely authentic, but compromises are required when scaling down. Still on the reject barrel, as a trial run.
The HSS cutter is mounted in a tight 3mm wide slot in 16mm silver steel. The 4 mm cap screw pushes the cutter up by 0.2mm per full turn of the screw.
The following video shows an air cut of the rifling cutter in the CNC rotary table on the CNC mill table. Then some actual cuts in a 1:10 scale cannon barrel. This barrel was a reject, and was used to practice the rifling cuts.
You can click on the arrow in the box below, or see the video full screen in YouTube.
As previously detailed, the rifling cutters which were made from a broken Brobo blade were unsuitable because I had not taken into account the thinning of the blade due to hollow grinding.
So I bought some high speed steel in the form of woodworking thicknesser blades, which were 3mm thick. Also, I redesigned the cutters to be a bit more robust, and take a 4mm pin instead of the previous 3mm pin, which looked a bit spindly.
6 cutters from one thicknesser blade 225mm long, 3mm thick
I have been unwell for 1-2 weeks with a respiratory disease. I twice requested Covid-19 testing, but was declined because I fell outside the guidelines. At the same time my wife fell ill with similar symptoms, but her situation rapidly worsened with severe asthma, and she required a hospital admission. She was given the Covid test, but it was negative, and it turned out that she has a different virus named RSV (respiratory syncytial virus) which causes croup in infants. So it seems likely that I have the same virus.
The problem is that we are coughing constantly, and sleep is very interrupted. And we need to continue self isolation just to avoid coughing near other people. I feel some empathy for infants with croup.
So not much happening in the workshop.
But I have been accumulating various bits and pieces that will be used for bronze casting pieces for the Armstrong cannon project.
First, the metal melting furnace. 10amps, 240v, 2600w, 1200ºc. Graphite crucible.
This should melt alu, copper, bronze, but not steel. Is there a town named “Italy” in China?AUD$405
And some quite reasonable gloves.
A second furnace is needed to prepare the mould. This was a quite old pottery furnace, used by a lady for ceramic painting. Purchased by me second hand, (AUD$700) and knowing that some repair work would be required.
It is a good size, and heating coils are intact and well seated. I do not know if the thermocouple works so I have ordered a spare.
The firebricks are in excellent, almost unused, condition.
It is using the rated 2600w.
The electrics work, but most of the joins and fittings are rusty. I will clean up the joins, and replace the fasteners. I also intend to replace the power switch with a digital control.
To make the mould I have chosen (on advice) a jewellers investment powder, normally used to mould rings and brooches with very fine detail. It is not cheap (AUD$130), and must be handled carefully and not inhaled.
The steel mould cylinder, and rubber end piece.
Wax cylinders to be used as supports, sprues and vents.
And finally, the vacuum unit, for removing air bubbles from the investment powder mix, (AUD$200)
A significant financial investment, and not finished yet. And no guarantee of acceptable results. I did obtain a quote from a professional caster, but it was even more expensive. So, I will be giving bronze casting a trial soon.
Below is a video which was recorded by my machining mentor friend, Stuart Tankard. Stuart made a milling attachment for his Boxford CNC lathe, and he demonstrates it in the following video by making some lovely small valve control handles.
I followed in Stuart’s footsteps by making a similar attachment for my identical Boxford 125 CNC lathe, but I have not yet video’d it in action. Not much point when Stuart’s video is so good. I really like the absence of irrelevant, irritating music. Just machining sounds. Enjoy. (if you want to see it full screen, copy the YouTube address from the settings icon).
When I looked closely at the rifling cutters which I had lasered out of a broken Brobo saw blade, I realised that I had boobooed. I had measured the thickness of the blade at 2.5mm, which was actually a bit thinner than I wanted, but would have been acceptable. But when I measured the cutters, they were only 2.2mm thick. Reason? The saw blade had been hollow ground, and the blade inside the teeth was thinner. Too thin, I decided.
So after some wailing and teeth gnashing I have ordered some 3mm thick tool steel in the form of planer blades, which I am pretty sure will not be hollow ground, and I will ask the laser cutter to cut me some more blades. So waiting waiting.
And I am setting up the cannon barrel for rifling. The CNC rotary table (stepper motor hidden behind) will be bolted to the CNC mill table. The barrel is held in the jig which is held by the mill quill. The cutter, (not seen in this photo) will be drawn out of the barrel by the mill X axis, while being rotated in the A axis by the rotary table. That is the plan anyway. But still waiting for bits to arrive so I can finish the cutting tool.
The Armstrong cannon barrel held to the mill quill, and the rifling cutter will be held by the CNC rotary table.
The rifling tool which I will not be using because the cutter is too narrow. The cutting edge just peeping out of the slot will be dragged and twisted through the barrel bore. The cap screw adjusts the degree of protrusion.
BRONZE CASTING
Meanwhile, I am accumulating various bits of gear to do some bronze casting. An electric furnace with graphite crucible from China, Some jewellery investment material for the moulds, and a second hand pottery kiln for preparation of the moulds, and melting out the PLA 3D printed parts. I will take some photos when it is all here.
And SWMBO has conscripted me to assemble and install some kitchen cupboards for a property which she is renovating.
These are flat pack units. Kaboodle. Well designed and CNC cut and predrilled. Not quite finished. Waiting for the stone bench tops to be made and installed, and for appliances to be wired and plumbed. Frankly I would prefer to be tidying up my workshop, but hopefully I am gaining some “Brownie Points”.
And about the last. The fibre optic network was commenced about 3 years ago, and I applied for a connection shortly after.
Despite living in the centre of Victoria’s second biggest city, my house was not connected to the National Broadband Network until today.
Until then I have coped with download speeds as low as 1mb/sec, and uploads as slow as 60kb/sec. Do you wonder why I upload so few videos?
Today, the NBN was finally connected. The download speed is a blistering 50mb/sec, and uploads 25mb/sec. Wow!
Just to celebrate, I am posting some pictures. Not much to report from the workshop, but I am accumulating some items in readiness for rifling the model cannon bore.
This photograph would typically have taken 60-120 seconds to upload previously. Today it took about 5 seconds! As you can see it is a cold saw blade which has seen better days. My bad, unfortunately. But I saved the pieces, because these blades are made of high quality tool steel. I have had some parts laser cut .
The laser cutter left the tabs intact so the tiny parts would not be lost.
The 2.5mm thick part popped out with a bit of finger pressure. Not much tidying up required here, but I will sharpen the cutting edge. This will be the cutter for the rifling of the model cannon.
This is the first time I have had parts laser cut, and I am impressed by the accuracy and smoothness of the cut and the narrow kerf (0.2mm). Oh, and the cost. It was surprisingly inexpensive. ($AUD26).
As a beginner, I have a fair percentage of unsatisfactory prints.
Print breaks free of plate.
Supports fall over.
Overhanging areas insufficiently supported.
Holes appearing due to wrong settings.
etc. etc. etc.
Most of the time I just bin the failure, change the settings or setup, and make another print. And wait another 2, 9, 12 or 24 hours…… Not a huge financial cost, but does involve waiting. And I am not very good at that.
I used to grow olives and make olive oil.
Sometimes the bottles of oil were sealed with wax. Melting point 85ºc.
After a failed print of 6 items today, due to inadequate supports of overhanging areas, I wondered if the holes and thin areas could be fixed with the bottle sealing wax. After all, lost PLA casting is just a descendant of the lost wax method in the metal casting process.
So I found the left over remnants of the bottle sealing wax, and heated up a soldering iron.
One of the failed prints. This is a wheel trolley bracket for the model Armstrong cannon. The moth eaten area was overhanging, and the support had fallen over. The area was thinned and the holes were not properly formed. If a brass or bronze casting was made from this, it would have been unusable.
The 850g slab of bottle sealing wax, and soldering iron. I do not know if this supplier is still available. It was not expensive.
The soldering iron is heated, dipped into the wax, and the molten wax carefully dripped onto the deficient area of the print, gradually building it up.
The wax can then be shaped with the soldering iron, or a heated knife, or even a finger or thumb. I also tried a blade shaver and sharp knife. I think that my soldering iron, and finger were the best tools.
The repaired area. It looks unsightly, but of course the wax will all disappear during the casting process, along with the PLA.
I am probably reinventing the wheel with this idea. Again. But have not seen it used anywhere else. So there it is. I think that it will be useful to me.
PS>. 12 hours later. I now realise that this is so old hat that I am embarrassed that I posted this. Reinventing the wheel,… that’s me.
My model Armstrong cannon has some components which will be difficult to machine, and would involve silver soldering many tiny pieces.
For example, the steel brackets in which the wheels are supported, and the centre column.
There are 4 trolleys like this. Each one has 2 or 3 wheels. It is a Z shaped profile with 3 gussets visible and 2 more inside.
The centre column. It could be fabricated.
But being basically lazy and always looking for the easy way out, I have decided to investigate the possibility of casting these parts. And some others.
So I have printed them in PLA filament, with a view to a “lost wax” type of casting process. It will be “lost PLA” of course. Maybe doing the casting myself. But also checking the possibility of having it done professionally.
The PLA printed parts which will be melted and burned away in the casting process, have to be as well finished as possible. So I have been experimenting with various settings in 3D printing. One problem is that the molten plastic thread has to be supported. Overhangs up to 45º or even 60º can self support. And even horizontal overhangs can self support if the gap is not too big.
But this gap, about 20mm, proved to be too big…
The threads are partly bridging the gap…
Horrible. It is the underside, but even out of sight, it is unusable.
So, I am printing up some supported versions, even as I type this. And I am going to look at some casting equipment which I might be able to borrow. Apparently the gas furnace is very noisy, and it needs a home with no close neighbours. List…. a furnace capable of melting bronze, a crucible, investment casting powder, protective gloves, helmet or face mask, leather apron, tongs, slag ladle, a casting box. There are many YouTube videos on the subject of lost PLA casting. Watch this space. But if the quote for professional casting from my printed molds is not too fierce, I will probably take that path.
3D printing is really slow. So slow, that the machine is left unattended to continue the print, overnight in many instances. The print head is set at 205ºc and the table at 60ºc, and it does bother me that this hot machine is left unattended, unwatched. I do not know if any fires have resulted, but fires are of some concern, particularly here in Oz.
A substantial component of the printing time is the hidden, internal structure of the object being printed, the “infill”.
In this photo I set the infill at only 3%, but to compensate for that I increased the wall thickness. The result was a nicely rigid article, but it was a 24 hour print.
My question. At this point in the print job could I have paused the printing, and filled the cavities with a substance which set hard. It would have to be done carefully of course, and keeping the level below the printing edge. It would also have to be cool or cold, so the PLA did not melt or distort. It would also need to be able to be poured, or injected. Plaster of Paris comes to mind. Car filler bog would be too viscous.
My aim (as it were) in making this model cannon is to have a high visual quality exhibition piece.
It is a 1:10 scale model, 1866 Armstrong 80lb, rifled muzzle loader, blackpowder cannon.
One question which always arises is whether it will be actually fired. My answer is that if it could be fired legally, it would be nice so I could make a video. However, Australia has very strict gun control laws, (with which I totally agree), and I do not intend to flout those laws. So this gun will not be capable of being fired. It will have no touch hole.
To satisfy the visual appearance of a touch hole there will be a laser printed dot at the location. Along with laser engraved Queen Victoria insignia, sight lines, etc.
But, it IS a rifled cannon, so I do intend to rifle the barrel. And that needs to accomplished before the trunnions are fitted, and after the cascabel is fitted, so the orientation of the rifling is as per the original.
The original rifling. The 3 grooves are each 30mm wide, (clockwise or anticlockwise, not sure) and extend up to the edge of the powder chamber. They are about 2 mm deep. The powder chamber is slightly wider than the barrel bore, being continuous with the depth of the rifling grooves. It is academic, because it will not be visible, but I will make it (the powder chamber, and the whole model) as accurately as I can, for my own satisfaction. Fortunately the powder chamber is accessible to machining from the breech end, because the cascabel is screwed into position, and is removable.
Yesterday I started making the cascabel. It was difficult. The steel thread is lathe cut first, then the shape is lathe CNC’d. Then there is milling the insides, and making a removable pinned rope retainer. The third attempt was the most successful, but I am still not satisfied, and so there will be another one made today. This is what I have so far…
The turned barrel, threaded to accept the cascabel. More work is required on the cascabel.
The cascabel is mounted in an ER40 chuck. It has been drilled and milled, and a removable insert is temporarily glued into place pending more machining.
Rifling. Searching YouTube reveals multiple tools and setups from US sites. Here are a few screen shots to show you some varieties.
From the sublime ….
to the other extreme…
No. I will not be using a PVC pipe lash up.
The amateur designed and built machines are interesting….
Sine bar on the right.
Then there is the method of pressing a button cutter through the bore. My bore is an odd size, so if I used this method I would need to make my own cutter.
This one is a computer animation of a 19th century rifling machine, now a museum exhibit. Can you see the barrel? Armstrong probably used a much larger version of this type to rifle his cannons.
But I think that I will use none of these methods. I have a CNC mill and a CNC rotary table. Mach3 can control both of these machines simultaneously. If I mount the cutter assembly in the rotary table, and the cannon barrel to the mill quill, I should be able to cut the rifling grooves. Still working on this one.
Naval Gunnery. A Description. by Captain H. Garbett. R.N. 360 pages.
Was originally published in 1897, and is a book which has been considered by academicians and scholars as being of great significance and value to literature. As such, it has been reproduced by Alpha Editions in an inexpensive, facsimile, paper back edition.
I came across an article about rifled muzzle loading cannons which referenced the book, and led me to purchase it from the Book Depository for $AUD20.
It, the book, is fascinating. 1897 English, is beautiful to read, non ambiguous, and unusually, does not provoke the grammar Nazi in me.
And the book has answered my questions about cannon construction. Not completely, mind you. I still do not know how they managed blind rifling. But most of the first 78 pages are about muzzle loaders, particularly Armstrong muzzle loaders. With diagrams.
One question which was answered was about the “recoil tube” located below the barrel of the Port Fairy 80 lb RML’s. I wondered whether it was like a gas shock absorber. The book explains that these long cylinders had a piston, and were filled with “Rangoon Oil”, (look it up. It is in Wikipedia), and they were indeed designed to moderate the rate of recoil of the cannon.
Another fact about rifled cannons… the rifling causes the projectile to emerge from the cannon slightly to the left or the right of the cannon axis, depending on whether the rifling is clockwise or anti-clockwise.
The book has chapters on breech loaders, naval mountings, quick firing guns, magazines, shell rooms, loading arrangements, sights, powder, cordite, projectiles fuzes, battleship development (up to 1897), battleship organisation and manning.
360 pages, 12 plates (black and white), 113 text illustrations.
If you have an interest in pre-dreadnought naval guns, this book is highly recommended.
One of my US readers has made a model rifled cannon, an Armstrong 110lb breech loader, 1:9 scale. And it looks superb! Best of all, he has made 2 videos of firing it. I definitely recommend checking out the build and the firing in the link below.
I will substantially copy the rifling setup which Jeff used. My sincere thanks to him for the information. (ps. although Jeff’s setup was tempting, eventually I used a CNC rotary table and CNC mill to do the rifling. See later posts.)
After 3D printing a plastic 1:10 barrel I decided to have a go at turning one in steel. I had a length of steel 70mm diameter and 290mm long, which was just too short to turn the entire barrel, so I decided to make one of the breech reduction rings separately, when I make the cascabel.
I did not know what the steel grade was, but it was off a machine so I thought that there would be a good chance that it would be reasonable quality.
The length of rod next to the printed barrel.
The turning was initially fairly routine.
and I was really pleased with the finish which was appearing.
Mountains of hot swarf.
The roughed out barrel. I used the 16mm drill bit to drill the bore from both ends, but there was still 50mm or so beyond the reach of the bit. So I silver soldered the drill bit into a length of silver steel (drill rod).
And quickly completed the drilled hole.
Then transferred the piece to the CNC lathe, and shaped the barrel exterior.
I experienced 2 problems with the CNC turning. The tapered chase of the barrel, and the rounded fillets came out really well, but the straight sections of the breech developed chatter marks. I was preparing to take a skim to remove the chatter marks when I bumped the manual CNC control, the cutter dug in, and I got a deep score in the breech. And broke the carbide cutter. I turned away the dig in, but it left the breech diameter 3.5mm undersize.
I have no more steel of that size, and it will be quite a while before I get an opportunity to buy some. So I persisted with the slightly undersized barrel. It will be 62mm diameter rather than the intended 65.5mm. I still have not decided whether to scrap it and start again. But if I can get some more suitable steel I will remake it. I might even use the undersized barrel to make a 64lb Armstrong RML, which had a smaller diameter breech than the 80lb RML which I am making. (note added 19 Jan 2021… The Armstrong 64pd and 80pd barrels had the SAME dimensions. The main difference was that the inner tube of the 64pd guns coiled iron, but in the 80pd guns was solid ended steel. “Naval Gunnery” Garbett pp52-53).
I showed it to SWMBO. “That is beautiful” she said, somewhat to my surprise, and being surprised by its 3.5kg weight.
Today was humid. But I hardly noticed. I was attacking a piece of 72mm diameter steel rod for the Armstrong 80lb model cannon barrel. Enough of the plastic printed shit. Now for the real material..
It was a piece of an axle. No idea of the exact material. But it is magnetic, turned beautifully. So not stainless.
The roughed blank, and the plastic printed model.
Next problem was to produce the 16mm bore, through 285mm.
None of my 5/8″ (15.87mm) or 16mm drill bits were long enough, so I drilled from both ends. Still have a substantial chunk in the middle. The cutting fluid is my own mixture of olive oil and kerosene. I used to grow and make olive oil and I have quite a bit left over.
The roughed barrel, ready for CNC finishing. And a 16mm drill bit which I turned down to a 10mm shank, and a piece of 5/8″ drill rod/silver steel drilled to 10mm, which I will silver solder to the drill bit to make it adequately long to drill through the whole barrel tomorrow.
The roughed barrel, and the 16mm drill bit ready for silver soldering. Yeah. It is a bit longer than necessary.
Turning cannon barrels is really satisfying. Still considering how to manage the rifling.
There is quite a learning curve to 3D printing, and most of my prints so far have exhibited considerable room for improvement. There are some helpful YouTube videos on the subject, but at my beginners level there is still a lot of trial and error.
I am still planning my next cannon model build, and printed some cannon barrels to improve my printing skills, and also to have a plastic model of the barrel to help decide about construction methods of the metal model.
This is a 1:20 print, but was unsatisfactory because the cascable, and the rifling did not print.
The next prints took 22 hours (vertical orientation) and 24 hours (horizontal orientation) each.
Firstly the vertical orientation..
It starts with a thin line which marks a little beyond the outside outline of the model to ensure that it is properly located on the printing plate. Then a thin base to ensure adherence of the model to the printing plate, for the duration of the printing. My plate is heated to 60ºc, which is not essential with the PLA filament which I am using. I changed the filament colour for aesthetic reasons.
Each layer of filament adds another 0.2mm of height. The rectangular columns support the overhanging parts, and increase the overall support of the model during printing.
The printing is finished after 22 hours. I can already see some mistakes. The barrel should be smoothly rounded, instead of faceted.
After breaking off the supports. Next to a bit of workshop rod which I will use to make the actual cannon model. Not quite long enough, but the rifled gun tube and cascabel will be made separately so the steel rod will be long enough for the rest of the cannon.
The next print was horizontal…
I made the supports more densely placed to improve the support. The cannon barrel is just appearing in the centre.
I left the printer to continue overnight, and this is what I saw next morning. Note the longitudinal placement of the plastic fibres. Infill set at only 3%, which was adequate. I increased the outside wall thickness to 5 layers, which was plenty thick enough.
The finished horizontal print on its supports (front) and the vertical version (behind). Apart from the facets, the appearance of the vertical version was better IMO.
Now I am ready to turn the barrel in steel. I have obtained a facsimile book about naval artillery which was written in the late 19th century, it reveals that the Armstrong barrels were made in concentric pieces, and heat shrunk together. I will adopt a similar method, making the cascabel and the central rifled tube separately from the breech sections. Not decided whether to heat shrink them together, or silver solder, or Loctite. (ps. a week later. Changed my mind. Making the barrel from a single piece of steel)
The artillery book also answered my question about 64 -80 lb cannon and bore sizes. When round shot was replaced by pointy cylindrical projectiles, the projectile weight could increase by increasing the length rather than the diameter of the projectile. And some 64lb cannons were redesignated as 80 lb cannons, after modifications which did not necessarily alter the bore. Unfortunately the book does not answer how the rifling was accomplished with a closed breech.
And I made another workshop tool. This one is a lathe tool height gauge.
I expect that the tough PLA will stand up to workshop treatment quite well. It is light, very visible, will test upright and upside down tool bits, and will hang on a conveniently placed hook. Also, it is within 0.01mm of the required 38.05mm tool height. A light rub of the base over fine emery paper will get the dimension right on.
My 3D printer. Bought from Amazon on a special offer. $AUD279. Worked straight out of the box after minimal assembly, and using the supplied plastic filament (PLA). You can see the large gear on the platten which I drew up using a CAD program. I used the software (Cura) supplied by the printer manufacturer (Creality). The printer is a Creality CR -10S. The “S” refers to a “filament out” sensor which I have not yet installed. I read some reviews of the printer before spending my money, and so far I am very happy with it. You might notice some bracing bars which I bought separately on Ebay. Not sure if they are necessary, but they might improve the print quality by reducing vibration in the printer.
These gears and shafts were printed. They were used to check the sizes of parts for my next model cannon build. I used a program called “Gearotic” to plan the gear module, teeth numbers, distance between centres etc. Gearotic is also great fun.
The printed gear and pinion quadrant on a background of a photo of the real cannon. On my model the gear and pinion will be made of steel or brass, machined from bar stock.
Another part sitting on a photo of the original. This demonstrated that I had got the corner chamfer a bit wrong. Much better to discover the fault at this stage!
A half size print of the barrel. This was just for fun. The final part will be ~300mm long, and will be machined from steel. This print took almost 4 hours.
A print of the centre column which the cannon chassis sits on and traverses around. It is ~60mm tall. It will be tricky to machine from solid bar. Could be fabricated in pieces and silver soldered together, but I am considering using the printed part to make a mould and cast the part in brass or bronze…… The original cannon column has an 5-600mm extension into the concrete base which my model will not need.
So far all of these prints have been made from PLA filament, which I read is easy to use, tough, rather brittle, and has a low melting point. It is also inexpensive (about $20-25 for 1 kg). I am still on the supplied small roll which came with the printer. Future prints will be in colour!
The weather is a bit cooler today, so I might get back into the workshop and make some metal swarf.
Some images of what I am planning to be my next model build. As mentioned in a recent post, I photographed and took lots of measurements of this Rifled Muzzle Loader at Port Fairy, and have been searching the web for more information. It is said to be an 80 pounder, but the bore (6.3″) is more consistent with a 64 pounder. Can anyone shed any light on the discrepancy?
(note added 20/12/20… I have now completed the model of this cannon. See photo at end of this post. To answer the question above, my reading indicates that the 6.3″ bore was used for both the 64lb AND 80lb cannons. The 64/80lb refers to the weight of the projectile. The Port Fairy cannon in the picture is indeed an 80 lb cannon. The extra capacity of the projectile and the gunpowder charge was permitted by extra strength of the barrel provided by a more advanced construction method.)
Yes, there will be some interesting machining challenges.
Not looking forward to all of that riveting. Considering options.
Most of the photos were taken with a Panasonic Lumix camera, but some, like this one, were with my iphone, using an App named “My Measures” which accepts annotations and measurements. The barrel “diameters” above are actually circumferences. And the “19” is the plate thickness.
The emblem on the barrel surface. I am hoping to engrave this on the model, but there would be a lot of time cleaning up the image.
A web search turned up this image, which will be easier to clean up for laser engraving on the model.
And some basic diagrams of similar design
The rifling grooves are 1″ wide. 3 of them. How to make them?
I asked about rifling grooves at a GSMEE meeting, and Rudi showed me how it is done. He made these 2 rifling tools. They are pushed through the bore to create the grooves. The bottom tool was most succesful, because it has a pilot diameter. But, the tools cannot be pulled backwards, so both ends of the bore must be open. But what about the cascable end of the cannon. It is not a breach loader.
Then the penny dropped…..I remembered seeing this diagram…
The cascabel screws into the barrel. That opening will allow me to broach the rifling. I do not know how the rifling was made in 1866! (does any reader have information on that point?) Note also that these barrels were usually made with some concentric tubes of steel. I expect that the model will be one piece of steel, with the trunnions silver soldered.
And I have started drawing up the cannon, massaging the field measured dimensions (which were obtained with a builders’s tape measure)…
And doing gear calculations for the gear train and rack. Lots more detail to go into the drawing and plans. And thinking about construction methods meanwhile. Now who has a metal sintering 3D printer for loan?
See posts on this site throughout 2020 for construction of the model….
Crealty CR-10s 3D printer. The machinists parallels were my solution to ensuring that the horizontal arm is parallel to the base frame.
So, I took delivery of the 14kg box, and spent a couple of hours assembling the printer. It was partly assembled, as delivered, and if I had known what I was doing the final assembly would have been done in a fraction of the time. The assembly instructions were adequate. The wiring connections were well labelled. The wiring connectors were delicate, and I took care not to bend or break them.
The vertical frame bolts to the base frame, and it is surprisingly rigid. There are 2 Z axis stepper motors, and when not powered up, they can be individually turned. It occurred to me that the horizontal arm which the Z axis motors raise and lower should be exactly parallel to the base, so I placed the machinist’s parallels as shown in the above photo and screwed the horizontal arm down onto the parallels to set the horizontal position. I assume that the Z steppers will move the arm equally. (Hmm… I will check that assumption later.)
Next day, I downloaded the operating software. An older version was supplied with the machine, and the newer version would not work on my old XP Pro Windows computer, so I used the old version.
I spent some time manually levelling the bed, then ran the automatic bed levelling software.
The printed operating instructions are very basic. An Internet connection is assumed, and I did not have one available, so my first printed object was with default settings and the supplied white filament.
Somewhat to my surprise, it worked.
The platten is aluminium. A glass plate was also supplied, so I used that on top of the aluminium.
The filename was “dog”. I had no idea whether “dog” was a 3D dog, a picture, or whatever. Neither did I have any idea of its size. After an hour, I had printed a disk about 125mm diameter and 1.1mm thick. Then the disk came off the platten, so I aborted the print.
Today, after getting some advice from Stuart T regarding print adhesion I removed the glass platten cover and applied some special adhesive 3D printer cover. It is called “3M double coated tissue tape 9080A”. Then I printed 2 more items. Neither broke free. in fact they were difficult to remove at the conclusion of the prints.
This tiny Tyranosaurus was printed from a 3D file which I found on my computer. It printed in about 20 minutes. Default settings again. The supports were too big for the object, and when I broke them free I also broke off the T Rex arms. Some settings for supports need to be changed.
The next print was a tool which I planned for the 3D printer…..
The item is a speed handle for a milling vise. It is 80mm diameter with some grippy indentations on the circumference. The tricky feature to make is the hex hole, to fit a 19mm hex shaft. This is the 3D drawing, imported into the Creality software, so the G code can be generated.
First layers. Each layer is 0.2mm thick
The internal framework is a bit lighter than I wanted. I thought that I had chosen 90% density. (ps. a couple of weeks later. The speed handle seems to be standing up to the usual rough treatment in my workshop, despite my misgivings about its lightness.)
The speed handle on the vise. Nice fit. The print took over 2 hours.
I am home after a short holiday at Port Fairy, Victoria. Port Fairy is on the “shipwreck coast” of Victoria, labelled for the number of ships which were wrecked in the 19th century. Dozens and dozens of them, including the tragic “Loch Ard”. Port Fairy was a sealing, whaling, fishing village in the 19th century, but now survives on tourism and dairy farming. It was also the site of horrendous massacres of aboriginals.
Port Fairy was part of the coastal defences against a possible Russian invasion in the late 19th century, when Britain was the enemy of Tsarist Russia. Not that any invasion eventuated, or probably even contemplated by the Russians. But no doubt they were pretty pissed off by the defeats in the Crimea, so an invasion of a weak but gold rich British colony was not not totally ridiculous.
So Port Fairy, and nearby Warnambool and Portland were fortified with decent shore based artillery. The coast is incredibly rugged, with few landing places.
Today I saw some of the fortifications. And my next project?….
It is a muzzle loading, rifled bore, 80lb, black powder cannon (RML). The associated machinery is in poor condition, but much of it is present, and its original form can be inferred. Most of the external brass and bronze fittings such as sights and gauges have been removed, probably stolen.
The barrel itself is in good condition. It is fired to entertain the tourists every Sunday at 1200, and on New Year Day at 1400. Just a blank charge of course, about 1/8th of the charge which would have been used to fire a projectile. I was fortunate enough to be present at the January 1 firing, and it was awesome! Very loud. A sharp “crack”, and gout of flame, and air shock wave. Very impressive. Rated as an 80lb cannon. Far from the biggest ever RML, but still awesome.
And our model engineering society has a connection with the gun. One of our GSMEE members used to prepare the demonstration charge, and conduct the weekly firing. He operated a stone quarry, and was qualified to handle black powder and other explosives. He tells a story of one firing which had a funny ending. Someone else had prepared the charge, inserted it ready for firing, which was done. Unfortunately he had neglected to remove the powder container, which was a “Milo” tin. A few minutes after the firing, a very irate cop demanded to know who had fired the gun. The Milo tin had landed on his patrol car which was about 100 meters away.
No (legal) charges were laid.
And another connection… my son in law grew up in Port Fairy, and has fond memories of the town.
So I have taken many photographs of the gun and its carriage and machinery, and many measurements using a builder’s tape measure. The overall length is 4 meters plus protruding barrel, and if I use the same scale as my previous 3 cannons, 1:10, it will be about 400-500mm long. At this time I am preparing some drawings. Thinking about materials. Possibly steel. With some bronze and brass for the fittings. But I will finish the Southworth vertical steam pump first.
Found this photo of a very similar gun which was mounted at Port Jackson, NSW.
Back home now, and watching the news about Australia’s climate change fires, politicians posturing, and the president who ordered a murder. Absolutely appalled. “We got him”. WTF.
Having completed the model Trevithick dredger engine, and not having an inspiration to start another major build, I decided to make another steam driven boiler feed pump.
Earlier this year (2019) I made a horizontal, duplex, twin cylinder feed pump for the 6″ vertical boiler, but I had also purchased the castings and plans for a vertical, single cylinder feed pump, not having decided which version to fit to the boiler. The horizontal twin version fits and functions very well, but I decided to make the vertical version while I am thinking about another major build.
This is what it will look like. Hopefully. Single acting 3/4″ steam cylinder top, and 1/2″ water pump bottom.
The plans, O rings and castings. The castings have been cleaned up on the RadiusMaster, and the steam cylinder (top) is almost finished.
The 7 pages of plans are excellent. Imperial measurements and fasteners. I will use metric fasteners.
But I work in metric.
So over the past few days, excluding the ones over 38ºc (100ºf), I have been machining the gun metal castings. And making a real mess of it.
The Mess.
The steam cylinder bore. Bored with a boring head on the milling machine. Turned out nicely, but I decided to run a 3/4″ reamer while it was set up on the mill, thinking that the dimension would be more accurate. I did not notice until too late that the reamer was damaged. It badly scored the bore. I considered making a new cylinder from bar stock, but used the boring head to remove the scores. Now 0.75mm oversize. Annoying but not fatal.
Steam passage not centered.
The steam passage in the cylinder cutout is meant to be centered. It is off at a 15º angle, and is centered with the cylinder top, but not the bottom of the cutout where it should be. OK, it will not be seen, will not affect the function. Just a trivial mistake. That is the final oversize bore.
3. This one could have been fatal. All of the center drill holes for the screws and steam passages in the cylinder valve face were off by about 1mm. The workpiece had moved in the milling vice between setup and machining. I really thought that this would probably require a new part, but I decided to proceed and see what eventuated.
The middle 6 holes are the steam inlet and exhaust passages. Fortunately they are in the correct vertical position, and have just been widened horizontally by the incorrect centre drill holes, which should not effect the function. The screw holes merged into the incorrect holes, and were pulled a fraction laterally, but should be OK. At final assembly I will fill the incorrect holes with something, probably epoxy or gasket goo.
4. This was the most obvious error. Moved the mill table in the wrong direction, and the rectangular hole ended up with an extension. I don’t think that it will effect the function. And it wont be seen by anyone except me, and all of you blog readers. Oh, and now I have to kill you.
Bugger bugger bugger
5. This was another mill problem. I had changed the tools to a 1.6mm drill bit, and reset the Z axis zero. Or had I? Maybe I had neglected to hit <enter> after the reset. Anyway, the chuck crashed at high speed into the job, impaling and snapping off the drill bit, gouging the steam chest, and the drill chuck gouged the milling vice. The chuck survived but required some remodelling on the belt sander and then a diamond file. The vice jaw also needed some impact craters to be flattened, then swapped out to another less critical vice.
I flattened the gouges in the steam chest face, and I will make sure to fill those with something at final assembly. The embedded drill bit can stay there, after flattening it with emery paper.
There were some other more minor issues, which do not bear repeating and prolonging this missive. This all happened over 2 days. Mistakes are made, and I console myself with my father’s advice “he who makes no mistakes makes nothing”. But, this is the worst run of blues which I can remember. It IS hot, which is not ideal machining conditions. So what do I do?
Well, maybe it is just a bad patch, and things will be better next session. And, I will try to be not SO impatient to get things finished that I don’t double check. I (and you) will just have to wait and see.
BTW, have a safe and happy new year. 2020. It is 101 years since we had a double number year (1919), and most of us will not see the next one (2121). So make the most of it!
Not mine, unfortunately. This one is Stuart Tankard’s. It is a Ytterbium generated, 30w, fibre laser, and the wavelength is such that the 0.01mm diameter beam will burn holes in metal. Ytterbium, for those who can’t be bothered to look it up, is a rare earth metal, atomic number 70, Stuart has used the laser to cut parts from a 1.2mm thick hacksaw blade. And in the following video he is making marks in a work-tool rest which I will use on my Radius Master sander grinder.
It is a 360º protractor, and grid lines at 10mm intervals. Looks purposeful. Time will tell if it is useful.
Watch the video. I am experiencing tool envy.
Listening to my own voice is pretty painful. I hope that it doesn’t grate too much on you.
The December meeting includes the competition for best model, best workshop tooling, and best engine. The 3 happy winners were all from Geelong.
Stuart Tankard, John Viggers, Swen Pettig
Trevithick dredger engine model by John
CNC lathe tools, toolholders and toolpost milling attachment by Stuart.
Following is a video of Stuart’s toolpost milling attachment in action. It has been posted before, but is worth watching again. It is quite remarkable.
(Photo of the flame gulper to be added.)
But, the best part of the meeting was this demo of a model aeroplane which was made by Don. The plane weighs 2.5 grams!!! The wing material is mylar which is 1 micron thick!!! The flight was cut short by hitting a ceiling projector, but apparently the world record for a flight by a similar plane lasted for over an hour! This YouTube video has had 360,000+ views in 5 days!
The Radius Master is a quality 48″ x 2″ belt sander which is impressively versatile with its 7 work stations.
The work station which is vertical, and against a platten is the one which I expect to use most often.
Vertical belt, and using the backing platten.
But the supplied work – tool rest is a bit narrow for my taste, and I decided to make another one.
I really like the one which was supplied with the Acute Tool Sharpening System (ATSS).
The Acute Tool Sharpening System from Eccentric Engineering.
So I bought some 4mm steel plate and cut it to size (150 x 150mm), and CNC milled a support bracket to fit the Radius Master.
The Radius Master with larger work-tool rest.
The rest is adjustable for angle and distance from the belt. Copied from the original. The bracket is screwed to the plate. I did not want to risk heat distortion by welding the join.
Then the penny dropped.
Why not use all of the ATSS fittings and fixtures on the Radius Master? So that is what I have done.
The ATSS system looks quite at home, yes?
Hey Gary Sneezby, maybe you should do a deal with Radius Master.
I can quickly swap the ATSS fittings and fixtures between the CBN grinding wheel and the Radius Master. It will be interesting to see whether the cubic boron nitride wheel or the belt is preferred for different applications. I expect that the belt will be best for quick removal of material and the CBN wheel for tool sharpening, but we will see.
Oh, and by the way, the bigger work plate does not interfere with any of the other work stations.
And I will ask my friend Stuart to laser engrave some guide lines on the plate. I have a new design to try.
And finally, here is a link to the video of using the ATSS, by Eccentric Engineering. It is worth considering. If you have not done so, I suggest that you look at Eccentric Engineering’s other tools too. They are very interesting. The lathe parting tool is the best one which I have used. And the Diamond lathe tool gets more use on my lathe than any other.
OK, now I realise that few of my metalworking, engine modelling, machinist friends will be interested, but just in case……a history book review….
THE RISE OF THE HELLENISTIC KINGDOMS 336-250BC
Philip Matyszak
Hardcover. £20 RRP
It is satisfying to read a book which plugs a gap in the history timeline. I chose this title because Philip Matyszak is a terrific author and I always enjoy his books, but once I had read the initial chapters I realized that I knew very little about the kingdoms which remained after the split of the empire of Alexander the Great.
The first third of the book summarises the career of Alexander and his wars of conquest. Then the maneuvering and wars which determined how the empire was to be divided, and who the rulers would be. Then a closer look at each kingdom. The west (Greece, Macedonia), the Seleucid empire (Syria, Persia, parts of India and Afghanistan), and Ptolemaic Egypt.
Matyszak emphasizes that the Hellenistic kingdoms period was not just an interregnum between classical Greece and Rome, but a period with its own significance in warfare, the arts, philosophy, etc. Three of the seven wonders of the ancient world originated in the Hellenistic kingdoms.
Unfortunately, there are many place names in the text which do not appear on the four simple maps. Why can’t decent maps be considered an essential component of history books?
(If any of my metal working, modelling, machinist friends would like to borrow this book, just ask.)
Doesn’t sound particularly interesting? That was my thought when I read that this book is a catalogue. After all, who reads a catalogue?
However, the artwork on the covers is attractive and interesting, and I do have an interest in ships, models, modelling and history, so I opened a few pages at random. And was transfixed! This book is glorious! Back to page one, read a few pages, then worked through every one of the 373 pages.
The photographs of the models are beautiful and expert. Most are laterals, but some are of smaller details. There are many historical photographs, pictures of modelers in action, previous exhibitions. To describe the pictures as “lavish” would be an understatement.
Glasgow and the River Clyde was (and is?) famous for ship building. Most of the 676 models in the Glasgow Museum’s collection are of ships built or owned in this region, over the past 150 years. So this book includes models from the age of clippers and steam dredges, through the age of steam and dreadnoughts, to Queens Mary and Elizabeth, and later. A wonderful historical tour.
Chapter 1. Models in Shipbuilding (the whys and wherefores of making model ships)
Chapter 2. Professional Model Making (there were companies which made models for ship builders and owners for industrial and marketing reasons)
Chapter 3. Amateur Models. (including models made by French prisoners of the Napoleonic wars)
Chapter 4. Ship Models and Exhibitions
Chapter 5. Building the Collection
The Catalogue (220 pages)
Glasgow is now on my bucket list.
A few random pages to tempt you.
Yes, I do find dredgers interesting. Note who bought this one.
I have several tool sharpening machines, including an industrial Macson 3 phase machine, a Harold Hall grinder rest, and a Quorn Tool and Cutter Grinder.
But, the one that I use most often is this Eccentric Engineering “Acute Sharpening System”. It was made from a kit and plans supplied by Eccentric Engineering.
Photo 1: The Acute Tool Sharpening System (Photo courtesy of Eccentric Engineering)
The system consists of a table which is adjustable for tilt and height, a work arm consisting of parallel links and a work head, a straight arm which is adjustable for position and angle and which the work head will slide along, and various fittings for holding lathe tools, ER collets, and others.
Photo 2: My ATSS. The ATSS with cubic boron nitride wheel on the LHS, and the elegant but less frequently used Harold Hall grinder rest with diamond cup wheel on the RHS.
I purchased the kit of laser cut and spotted parts and the excellent 32 page bound plans from Eccentric Engineering. The parts in the kit require final machining, including drilling, reaming, tapping, turning and milling. It would be quite possible to use bar stock for the parts, having purchased the plans, but the kit is good value ($AUD 250 + GST) and it made the job quick and straightforward. A completely machined, assembled system is also available. Details at https://eccentricengineering.com.au.
Photo 3 These are the fittings which I made from the kit, and some extra parts which I bought later.
From the left: hex keys for quick adjustments, angle and gauge templates – most bought from Eccentric, but some made by me, tool holder centre, and collets on the right. Some of the collets are blank to be machined as required. Top right is an ER collet chuck.
Photo 4 This collet holds a 6mm lathe tool.
This post was not really intended as free publicity for Eccentric, although I am very happy to give it a good rap. It is actually to show a modification which I made to the ATSS table. Shown in the next photos…
My colleague Stuart Tankard recently acquired a CNC laser engraver which will engrave steel and brass and cut thin metal. I thought that it would be useful to have some accurate lines on the table in a grid, and others at angles to assist with setups. The grids are at 10mm intervals, and the angles are 30/45/60 degrees. In the above photo the straight slide is easily set parallel with the wheel face.
Of course, the cubic boron nitride wheel must first be accurately set to the table, and the grid assists with that….
Photo 5 Straight edge lined up with the wheel edges and grid.
Photo 6 And here the tool holder base is set at 60º to the wheel.
The angle gauges supplied by Eccentric will serve the same function. Time will tell if the table marks are useful.
Also I am thinking that the work table on the RadiusMaster could use similar guide lines!
I have been watching Ebay for a year or more for one of these belt sanders, but they just never seem to appear second hand.
Then I wondered about making a 72×2″ belt sander. I even bought a set of plans. There are many versions of these sanders on YouTube, of varying complexity and sophistication. The plans by Jeremy Schmidt looked very promising, well explained in his YouTube video, and the plans are thorough. But the sander appeared to me to be fairly large and very heavy, and it was not going to be a cheap build. I estimated about $AUD1000 by the time I bought a motor with speed control, and other materials.
Then, a stroke of good fortune. SWMBO really wanted me to do a rather unpleasant job for her, and I was not enthusiastic. She is renovating a small house. The previous tenant had a cat which was either incontinent, lazy, or constantly locked inside the house. Or maybe it was the tenant. Anyway, the carpets stank to high heaven. So bad, that SWMBO felt that she could not ask anyone else to remove the floor coverings and take them to the tip. But she was prepared to ask me. She knew that I really wanted to buy a RadiusMaster, and said that if I did the job, she would not object to the rather self indulgent purchase of the sander. I had not really decided what to do about the sander…. buy or build…. but it would leave me free to make the choice. So I did the job for her. After the initial assault on the olfactory senses, it was not too bad. Took a couple of hours. And very thorough washing afterwards.
I still had not made a final decision about the RadiusMaster, so a few days later I drove to the dealer, and had another close look. Meanwhile I had been reading reviews. And I bought one. The obvious quality, compact size, plentiful power, rave reviews, and ready re-saleability were all persuasive.
It came with a stand, not yet attached to the floor because I have not finalised the position.
It is made in Australia, and I was looking forward to understanding the instruction manual for a change
Assembly was straight forward, took about an hour. The instructions recommended a 2 man lift, but I managed OK solo.
Enough power for my uses. 240V 8.19A. No speed control, but that might be added in future.
Overall this is a quality machine, but one aspect was not up to standard.
The vertical grinding table was noticeably not square to the platen. In fact it was 2 degrees out.
I considered rejecting it and insisting on another table, but that would have involved another 2 hours each way to the dealer, so I fixed it myself. The angle bracket was quite solid 6mm thick steel, welded to the table. Some persuasion with a heavy hammer in the 6″ vise did the trick.
The grinding table is now within 0.25 degrees of the platen.
This table will be temporary anyway. I am intending to make a larger table, with fence slots, and and indexable protractors.
The RadiusMaster takes 48×2″ belts which are widely available and inexpensive.
The machine has 7 separate stations, which are selected within seconds. I expect that the vertical one pictured above will be most used. Others are…….
The 8″ 200mm rubber wheel, for hollow grinding (used in knife making)
The unsupported section of belt, and the notching wheels. The guards swing easily out of the way.
Horizontal positioning for pipe notching. 3 wheels are provided, and quickly selected, and other sizes are available. The horizontal position can also be used with an optional horizontal platen, which I have ordered. Vertical-horizontal positioning takes a few seconds.
Underneath view of the horizontal pipe notching rest. If it looks confusing, it is. This was one aspect where the instructions were vague and unclear.
That large, heavy, gold casting is the heart of the machine. A lot of thought has gone into the design.
When I have had some experience with using the grinder sander I will write a review. No buyer regret for a change.
Although my recent posts indicate that I have spent a fair amount of time recently on Google Earth Pro, I have also been busy in the workshop. Mainly finishing the toolpost milling attachment for the Boxford CNC lathe, but also fiddling with the laser attachment for the CNC mill. Neither of those projects is completely finished, but I thought that you might be interested in some progress photos.
This is what the Boxford TCL125 CNC lathe now looks like from the front. It is substantially modified from the original which I purchased 5 years ago. To mention a few changes…..
the axis stepper motors are bigger and more powerful than the originals
the ball screws are now 10mm diameter, compared with the original 8mm
there are some adjustable axis limit switches
the 3 jaw chuck is replaced by an ER32 collet chuck
there is a removable toolpost milling attachment with ER 16 Collet chuck, with a speed controller, cables, and panic switch.
there is a removable safety screen (not seen in the photo)
And hidden in the electronics compartment….
There is a 750 watt AC Servo spindle motor and controller (RHS, under the coiled cable)
The electronics have been replaced with a Mach3 compatible breakout board and associated peripherals. Anyone with an original 1985 machine will hardly recognise these components.
And the software is now Mach3, running off an old Windows XP computer. And using “Ezilathe” for most of the G coding, especially threading, and interpreting shapes which have been drawn as CAD dxf’s.
The new toolpost spindle works, but the software needs a bit more fiddling to tie it into the CNC controls of the lathe.
The Boxford has provided an excellent base on which to make these changes, and I look forward to producing some videos soon of the renewed machine in action.
Crater that is, on the moon. One of the few areas shown by Google Earth Pro in high definition. But I wonder if those nice sharp views will continue when these pictures become better known.
This is the northern half of Tycho crater. Tycho is approximately 80km diameter, over 3000m deep, with a prominent central mountain peak. This picture is taken from 80km above the surface of the moon.
As we zoom into the northern rim of the crater…..
Hmm. Those rocks look interesting…. some right angle shapes….
You would swear that those are buildings… And look at the shadows that the biggest white shapes are casting. Hang on, shadows. Those big white shapes are not only rectilinear and big, they are up above the ground surface. The yellow line is 1000m long, for comparison.
At this magnification some pixellation is appearing, so there is no point going closer.
Take another look at the biggest white shape. Does it remind you of anything? V? Antarctica? The following picture is from my post in December 2018.
The Moon co-ordinates are there. Take a look for yourself, using Google Earth- Moon. While it is still available.
Surveyor 7 landed 40km from here, in 1967, ostensibly to check potential landing sites for later manned moon missions. I bet that NASA has some nice clear pictures of the area. I do hope that I am still around when the truth finally comes out.
When scanning Antarctica with Google Earth Pro today, which I do from time to time, I came across this flattish circular shape on top of a mountain…
Zooming in….
The Disk pin locates a tiny dot of interest…. 6 Nov 2012. Moving the Timeline date does not change the image.
It is 10km diameter, and fairly flat and smooth. The above photo was taken from 10.5km altitude.
You will note my marker labelled “Disk”. It marks a black dot, which I zoomed into….
Well, that looked a bit odd… quite circular, intense white and black areas. 31 meters diameter. The co-ordinates are on the screen if you want to check this yourself. Note the shadow to the west. It indicates that the central round lump with the “face” is actually a substantial pillar, with straight sides. There is nothing anything like it that I have seen, anywhere else in Antarctica.
So what is it? Zooming in closer (in 2012) does not improve the clarity. ?an odd heat vent causing local melting?
A bit of further checking reveals that the area is an 11352′ (3460m) volcano, which protrudes 2100m above the surrounding ice sheet. Mount Takahe. 76.28S, 112.08W, in West Antarctica. It is a large “shield volcano” which last erupted in 5550BCE. It erupted massively 17,700 years ago, and is thought to have accelerated the end of the last ice age. The smooth flat area in photos 1 and 2 is the caldera of the volcano.
That is very interesting, but does not answer the question… what is the strange “sphinx” like protrusion in the 3rd photo.
The above images were made in 2012. I cannot find any other zoomable satellite images of this area, despite other areas of Antarctica being photographed at least annually, and in some areas, several times per year.
Also, satellite images of most of the world’s volcanoes are available at http://www.volcanodiscovery.com , but Mt Takahe’s images are blacked out!
Please excuse my paranoia. And the clickbait heading.
The flat top is the ice filled caldera.
Almost worth travelling to inland Antarctica, and climbing an 11,000′ volcano to find out. Almost.
Oh, and by the way, there is a pyramid, or a mountain which looks distinctly pyramidal, in Antarctica… Look it up.
PS. 2 days later. Doing some more checking on Mt Tahake, I came across this YouTube video. I was not the first to think that there is some strange stuff there.
On the Remembrance Day theme, this one was sent by reader Jennifer Edwards, UK. It is from WW2.
Hi John,
As long as we are thinking of Remembrance Day, this is a photo taken by one of those front line battle photographers of my father who was a medic being awarded the silver star.
His company being led by a green lieutenant (90 day wonder) into an ambush was caught in a murderous crossfire of machine guns and mortar.
The lieutenant was screaming for a medic from a crater up in front. My father felt compelled to run under this indiscriminate fire to help him because he sounded so desperate.
When dad made it to him he saw that all he had was a broken ankle. Angry that he just risked his life for a non-life threatening injury grabbed the Lt. and broke his nose!
A bird colonel watching from the safety of a nearby hill saw my dad’s act of bravery and said “give that man a medal”. The lieutenant pressed charges for striking an officer.
So dad was busted to buck sergeant and awarded the silver star on the same day!
At 11am, on November 11, 1918, World War 1 ended. Or as many historians claim, phase 1 of WW1 ended. Phase 2 became known as WW2.
The following text and photos are about one of the allies main artillery weapons, and the modelling of it by reader Robert Irving, of NSW.
The 1916 Vickers 8” Howitzer.
The United Kingdom entered WWI with its traditional lack of preparedness. Defence funds had been lavished on the Royal Navy to maintain the ‘Two Fleet’ policy, whereby Britain could deter attack by having a fleet more effective than the combined force of the world’s next two largest navies. The Kaiser wanted a fleet to rival his cousin Edward’s and later cousin Georges. The ensuing arms race drained the tax revenue leaving little in the budget for the army. The army was still equipping itself for mobile warfare after the needs of the Boar War and had a good supply of very mobile light field artillery, very few machine guns and an inadequate inventory of mobile heavy guns.
The failure of the Schlieffen plan to take Paris and the channel ports, against stubborn resistance, resulted in the continuous trenches from the channel to Switzerland. German policy was to build a strong defensible line and hold their gains. To this end they employed their normal thorough approach and by 1916 had fortified their numerous layers of trenches with deep concrete dugouts to give protection and a modicum of comfort to their frontline forces. They had also retreated to gain the tactical advantage of high ground where applicable. France and Britain, understandably had an offensive policy and didn’t build strong or comfortable trenches. Break through, then attack with cavalry thinking dominated strategy and tactics . Germany began attacking the Verdun Forts in late February 1916. General Falkenhayns stated objective being to “Bleed France Dry”and this they were close to achieving. The British were rushed into the long planned attack between Serre and Montauban, nine miles of front, to relieve pressure on the French. The French were to attack on the British right flank, though this was scaled down due to the huge losses at Verdun. The British attack plus the diversionary attack at Gommecourt were together, known as the Big Push. This being the first major attack by Field Marshal Kitchener’s Volunteer Army, morale was at peak, despite the average three months the new battalions had spent rotating through front line duty; the sector was a quiet one.
In August 1915 the Vickers 8” Howitzer was approved however an order for 50 was not placed until March 1916 and delivery began in July 1916. The Howitzer fired a 91kg, 8” diameter shell a maximum distance of 11,000 yards, it’s trajectory was high and therefore it gave plunging fire, ideal, with appropriate fusing, to penetrate deep dugouts. There were a few makeshift large calibre pieces in operation in June 1916 but these were thinly spread along the nine mile front, they were mainly stopgap weapons made by modifying old naval guns. The Royal Field Artillery staple weapon was the quick firing 18 pounder, firing a projectile weighing 8kg with a range of 6500 yards.
1918 Vickers 8″ Howitzer.
Australian 8″ Howitzer battery
The attack was scheduled for the morning of July 1st and preliminary bombardment began one week earlier. Huge stocks of shrapnel and high explosive shell for the 18 pounders were in place, far fewer heavy shells were available. The plan was that the new spigot mortar, firing a basketball sized high explosive projectile, together with the 18 pounders would break up the fields of barbed wire and kill sufficient front line defenders to make the 100yard to one mile crossing of no-mans-land, without cover, survivable. Results on the wire were patchy and on the dugouts feeble at best. Only British forces adjacent to the French sector, with a high density of artillery, had a real chance success, near the villages of Fricourt and Montauban
The Attack began at 7.20am on that clearing misty July morning, with the explosion of a large mine under the German front line at Hawthorn ridge near Beaumont Hamel, followed by a series of similar mines at 7.30am. Orders to the first waves of infantrymen were to advance at walking pace with rifles at high port and occupy the German frontline. Later waves were to attack the second and third lines to facilitate a cavalry breakthrough. These orders ignored reports all week, from trench raiders, saying that the dugouts and occupants were intact and only the odd lookouts were killed by the bombardment. Also that the majority of the wire was undamaged.
In the first two hours of the attack, most of the 19,000 attackers who died on the first day were dead, or lying mortally wounded, without reaching the German lines. Likewise a further 40,000 casualties had occurred and the trenches were blocked by walking wounded and dead men. The storm of machine gunfire and precisely zeroed German shell fire, cut down attacking companies and battalions in rows that represented the waves leaving the trenches. The Battle of the Somme, as it was later known was doomed on the first day, the squadrons of lancers and hussars remained behind the British trenches unable to take part in the planned big break through. 1st July 1916 had the highest number of casualties for any attack by British forces. By comparison on the first day of the landings in Normandy in 1944, there were 4,500 total allied forces killed.
The failure of this attack is attributed by most historians to the lack of sufficient heavy artillery in the preliminary bombardment like the Vickers 8 inch howitzer,. Had the 50 guns been ordered three months earlier, who knows what lives would have been saved on both sides by shortening the war.
The almost complete model. OAL 450mm
THE MODEL
The model was built to a firm budget for an individual in the U.K. The agreement was to build a fair representation of the Vickers 1916 8” Howitzer with no more than 250 rivets. The final number of rivets was over 500. Construction took just under 900 hours and only the nuts, bolts, two hand wheels and main gears were purchased. The model was not capable of firing having a rifled liner in the barrel (like the original) that did not extend to the breech. The breech was a four segment rotating thread type operated by moving a lever through an arc of 45 degrees. The upper chassis had elevation and traverse mechanisms and the barrel had a spring loaded recoil ability. Rifling the barrel liner was a problem. Testing the single cutter broach showed location and spacing problems. Multi cutter broaching exceeded the pushing power available, even on aluminium. These techniques work well on large production machinery cutting four or five groove barrels. This barrel needed thirty plus grooves. Having seen a toolmaker friends EDM set up I had the idea of making a copper male button to be passed spirally down a steel liner cutting electrically in the electrolyte. It worked splendidly first go and took about 20minutes. (editor’s note… “wow”)
The wheels were approximately 7” in diameter, classic traction engine types, with the rims machined from thick walled steel pipe and the spokes laser cut. The chassis, upper and lower, were cut from solid plate rather than fabricated, this was due to budget constraints. The scale of the model was 11:1 and resulted in dimensions of : bore 19mm, overall length 450mm.
There were no engineering drawings used for the build only the line drawing shown and lots of web photographs, all of these were of later marks of the 8 inch and some were complicated by being shown in reverse from glass plates. The gun was still in service in 1939 though by then it had pneumatic tyres and lots of refinements.
Robert Irving 2019.
The drawing which was used to make the model..
Boring the barrel
Note the rifling.
Wide track
Wheel hub drilling jig
The spokes were laser cut
Turning the barrel
In recoil
Breech
Early assembly
Completed model
Hand for scale
The rims
So, again, thanks to Robert for the photos and historical context of this superb model.
This post will be of no interest unless you have one of these camera gimbals. I found, like other reviewers of the gimbal, that the 1/4″w thumbscrew which secures the gimbal to the camera is not trapped. I have lost it once already when I wished to use it.
There are two possible slots where the thumbscrew can be positioned, depending on the size of the camera, and I suppose that is the reason the thumbscrew was not trapped by the manufacturer.
The fix was not difficult for a machinist with a lathe and a 1/4″w tap.
I made a 1mm thick brass disk, 10mm diameter, and tapped a 1/4″w hole. Then milled a 1mm deep circular matching recess in the joining plate after carefully determining the correct position. Put the disk onto the thumbscrew thread after checking the position, then glued the disk to the thumbscrew.
Thumbscrew now trapped in position on the gimbal-camera joining plate. The brass round nut is glued to the thumbscrew and sitting in a carefully positioned, machined recess in the joining plate.
Of course, the positioning is for one camera only. But because the position is fixed, it makes joining the gimbal and the camera faster. If the gimbal was to be used for more than one camera, a slot should be machined rather than a circular recess. When I want to change cameras one day, I can easily melt the Super Glue, and machine an extra round recess or a slot in the plate.
Just a quickie to show you a progress photo of my current project.
It is a very small milling motor with a small ER collet, mounted onto the toolpost of my Boxford CNC lathe, which will convert the lathe from 2 to 3 axes.
At this early stage the toolpost holder and cylindrical motor have been mounted to the water jet cut bracket on the right side. Pulleys and drive belt yet to be fitted and I will trim the shaft at the left hand end of the motor. Then the motor wires are connected to a speed and direction and on-off controller.
The usefulness of this tool is apparent in the following video of a completed unit in use. The main spindle motor of the lathe is now a 750w AC servo motor, which can be controlled from Mach 3, to go to programmed positions and hold the position while a milling procedure takes place. Of course the milling procedure will be with small cutters or drills, perhaps up to 3-4mm diameter.
The idea, plans, and some of the parts are courtesy of Stuart Tankard, my very clever friend, whose completed machine is the subject of the following video.
Stuart’s video is republished here with permission. The original, with comments, is visible on YouTube. If you have technical questions about the setup, I suggest that you contact Stuart via his YouTube post.
When I was making the triple expansion steam engine I turned the crankshaft from a piece of 50mm diameter stainless steel rod. One centre for the main bearings, and 3 other eccentric centres for the big ends. I spent a long time marking out the centres, then turned the bearings, gluing in a packing piece after turning each one, so that pressure on the ends of the crankshaft would not distort it.
After a whole day on the job, I was pretty pleased with the progress, and I lined up the almost finished crankshaft with the bearings on the bed, to see how it would look.
#%&*##
I had made a 3mm mistake with the position of one of the big ends. It was a fatal mistake.
So I made another crankshaft the next day, and that one worked out fine, and is on the triple to this day.
The ruined crankshaft sits prominently on a shelf in my workshop, as a reminder.
Today I am making another confession, of another stupid mistake.
This was a beautifully smooth, accurate, keyless Rohm chuck which I used often in my mill, mounted on a quick release quality JT6 Japanese fitting. I used it successfully on drills down to 1mm size for several years.
But lately it seemed to have a bit of runout. Inspection appeared to show that the JT6 taper part of the chuck had dislodged a bit. Not the taper itself, but the sleeve that the taper was machined into.
So, I put it in the press to snug it back home.
No movement, so I pushed a bit harder. (stupid stupid stupid!)
BANG!
I don’t know what let go, but I think that I cracked the tapered sleeve. The chuck was seized solid. Would not move despite heavy persuasion. I had really buggered it.
O well, you live and learn. I figured that I would remove the chuck, buy a new one, and install it on the expensive Japanese JT6 spindle.
So I applied a gear remover, one of those double C shaped ones, with the hardened steel jaws, and tightened the bolts. But it would not move. Tightened the bolts further, and further, until I was not game to apply more pressure for fear of breaking the gear remover or the Sidchrome spanner. Considered applying heat with oxyacetylene, but I really did not want to wreck the Japanese fitting as well, so I put the question to a colleague at the model engineering club today. As a result of that conversation, this is what I did…..with an angle grinder.
As you can see.
I considered putting it on the shelf next to the crankshaft, but you know what…. I don’t think that I can bear to look at it, so it is going out with the rubbish to be forgotten as quickly as possible. (ps. now sitting next to the crankshaft)
The JT6 spindle seems to survived unscathed.
The other side of the chuck and the spindle, after separation.
In retrospect, I wonder if I should have tried some heat, but the chuck was busted, so it would not have made much difference.
These photos and description were sent in by reader Robert, from NSW, Australia
Robert’s model Emden gun
Emden Gun by Robert.
The cruiser HMAS Sydney forced surrender of the SMS light cruiser Emden in
November 1914, after a sea battle that reduced Emden to a non firing hulk;
a scene of carnage.
Sydney’s 6 inch guns outranged Emden’s 10.5cm Krupp’s. The surviving crew on
board Emden dutifully tossed overboard all the breech blocks, so the ten
captured guns brought to Australia are sans breech mechanism and none are
without significant shell damage. Two of the best preserved examples are
main deck guns, one in the Australian War Memorial and one at the Navy
Museum in Sydney Harbour. Both of these have gun shields, the third example
located at the corner of Hyde Park and Oxford St. Sydney, is a mid-deck gun
that fired from an armoured sponson and this was not fitted with a
gunshield.
The shore party sent to destroy the islands radio station escaped in a leaky
schooner and their story is real boys own stuff.
The sleek lines and proportions of the Hyde Park example attracted me to
make a model of it. In research on the history of Emden and its crew
(captured survivors spent the war in Berrima, another interesting tale) I
came across the story of SMS Konigsberg, sister ship of Emden, scuttled in
the Rufiji river delta, East Africa, harassed by a British battle fleet.
These guns were salvaged by the crew and using huge numbers of native
conscripts, were dragged through the bush to the German railway workshops to
be fitted with carriages and wheels, others kept as fortress guns. The range
of these pieces dominated fighting in East Africa until the Brits. could
ship out long range artillery. One gun was fitted to the German steamer SS
von Goetzen based on Lake Tanganyika and was the inspiration for the great
(fictional) movie African Queen. The defeat of the Konigsberg used aircraft
for spotting fall of shot and was the inspiration for another forgettable
movie starring Roger Moore.
Model details are: Length 356mm, height 140mm. Materials: Stainless Steel
base, the rest mild steel or brass. Traverse gear cut, elevation gear
segments purchased . Scratch built from photographs about 600 hours. Breech
chambers but does not eject round, recoil spring based, traverse and
elevation work as original.
Original Emden gun sans breech
Krupp gun on the SS Graf von Goetzen, Lake Tanganyika
Close ups of the model
Thanks to Robert for sending these great photographs and commentary. I have seen photos of some other of Robert’s superb model engineering, and look forward to publishing them on this blog.
2 videos of the triple and the vertical boiler and the Southworth boiler feed pump working together for the first time. Not perfectly yet, but working.
A gimbal is a device which keeps an object on a steady horizontal level, even as its support moves and tilts. Such as a ship’s compass.
Hand held videos often show unwanted evidence of movements due to shaking, walking or distractions.
Expensive gimbals have been available to professionals for a long time. Recently gimbals have become much less expensive, and available to people shooting videos on smart phones, mirrorless cameras, and DSLR’s.
The following video was shot on my iphone, without a gimbal, but about a gimbal, which I recently purchased. The video is brief, and not intended to be anything but a glimpse. To be honest, there is a bit of a learning curve with the gimbal, and I am just beginning.
I hope that it will help to improve my video shoots.
A beautiful spring morning became blustery, windy, hot yesterday. But I hardly noticed. I was in the workshop making these small steam pipe connectors.
Normally I would buy these fittings, because they are fiddly to make and not very expensive, but I have fitted new rings to the triple expansion engine, and I want to try it out on the vertical boiler. (see the previous post)
one of the tails was not drilled deep enough.
I needed only 2 of these nipple-tail-nut assemblies, but having made a jig to fit the collet chuck it was just as easy to make some extras for future use.
The jig is required because having made one end of the nipple, it must be turned around to make the other end and there is not enough material to hold in the 3 jaw chuck. So the jig holds the workpiece by the first made thread, and the piece is finished by holding it in the collet chuck. The jig will be saved for future use. It has external threads for 5/16″x32 and 3/8″x32, and internal threads for 1/4″x40 and 5/16″x32.
The tiny tails were drilled in 2 stages because there is an internal step, and the outer shape was CNC’d.
Still recovering from The Royal Geelong Show, where my beam engine and the Trevithick dredger engine ran for ~8 hours per day for 4 days, and required almost constant supervision. I was very pleased that they did so without a problem.
For future exhibitions I would like to also run the triple expansion steam engine using the vertical boiler, for which I recently made the Southworth boiler feed pump. And there are occasions where I might run the triple and the beam engine together from the vertical boiler. That arrangement will occupy a fair bit of bench space, and in this post I am considering options for the arrangement.
But first, I needed a steam outlet manifold to handle multiple engines, simultaneously, and hopefully to avoid a big tangle of pipes. Here is the manifold.
The manifold has 6 x ¼” outlets and one 3/8″ outlet.
Option one lines up the boiler and engine like this….
Option two is more compact, but ?less appealing. Pics following..
The lump of wood under the engine is temporary, just to give an idea of the heights.
OK, this post is just an excuse to show some pics. I have decided to go with option one. It is closer to the appearance if the boiler and engine were actually in a boat, and also will make it easier to add the beam engine to the right of the boiler if/when I run the two engines simultaneously.
And I doubt that I will be able to avoid a jumble of pipework. The triple has 6 pipes attached, the boiler has more, then there is the beam engine. And, I will need a water container from which to feed the boiler. That will be located behind the boiler. Still considering whether it should be a squarish box on a stand like the railway water towers, or a cylinder on a low stand. Any thoughts?
The “Show” was held over the last 4 days. I will not bang on again about my republican leanings. See posts from previous years if that persuasion is of any interest. The weather was ordinary. Quite a few showers and blustery wind. But we were mostly warm in the Vintage Machinery shed where our Model Machinery cage is located. Fairly good visitor numbers, but not much real interest in our model engine offerings.
I exhibited my beam engine and Trevithick dredger engines, both running on piped steam. The vertical boiler and feed pump was on static display, of no interest to anyone. My Stirling engine got the most attention from kids, who are attracted by the swirling spiral colours, and not much interest in the intriguing method of running. I am convinced that models must be moving, colourful, and have some relation to what people and kids see on television if they are to have any traction with the public.
But, the model and full size engine exhibitors enjoyed the displays, and an occasional visitor engaged in conversation. Here are some pics and videos of some of the shed displays. There dog shows, bird breeding, monster trucks, horse riding events, cattle and sheep judging, and side show rides but these were not recorded by me. I did visit the Amateur Astronomy display, and will visit the workshop of one of the exhibitors soon.
I had applied wooden lagging to the beam engine cylinder
Steam for the engines is provided from this Package Boiler at 25psi. Enough to turn them over. Capable of much higher pressures.
Cage Bench North includes the Trevithick dredger model, the beam engine and the Stirling engine.
Cage Bench South. Swen Pettig’s prize winning flame gulper, and 1″ Minnie under construction.
Stuart and Swen ?discussing engine repairs.
Model Engineering first prize!
And the full size triple expansion engine. The Vintage Machinery boiler is being upgraded, so there was insufficient steam to run the triple.
Yesterday I reseated the pump valves, reassembled the pump, then tested it on steam.
Most of the following video has the boiler at only 25psi, but I did run it off camera at up to 75psi.
After making the video I redirected the exhaust steam from the pump into the firebox. It actually seemed to improve the gas flame, maybe by acting as a blower. Not so sure about this being permanent though, because the exhaust steam contains oil from the displacement oiler, and I dont want that oil to be deposited in the firetubes.
I will make a water tank to supply boiler water. Maybe the exhaust steam could be passed through a heat exchanger in the tank, so the boiler feed water is preheated.
(if the video is not showing, click on the https link below)
Every time that I open my workshop I wonder if it will have been robbed. So far, I have had unsecured implements which are stored outside, stolen, and an attempt at stealing my Landcruiser ute, but no breaking and entering of the workshop itself. Mind you, any thief would have a tough time working out what to take… everything is scattered around, sitting where I last used it. And then there are the tiger snakes….
Reader Brendan has a couple of guard dogs for his workshop when he is not present.
They might not look too scary, but they do make a hell of a racket when a stranger approaches.
And Brendan’s workshop is not all in one location. I counted 5 separate locations….
The computer room and security monitor. Mostly CAD and G codes here.
The laser cutter occupies the entry porch. See the backing board pattern? That is from the gasket for my Trevithick engine.
Then the main workshop. Hmm… what is that red thing?
2 lathes in the garage. Hafco with DRO, and CNC with Siemens controller.
Meanwhile, in my workshop…
I am taking some of my stuff to an exhibition at the Royal Geelong Show in a week. The beam engine working on steam always gets some interest. And the Trevithick dredger engine has not featured at this event before, so that can go. I am currently working on the vertical boiler. The Southworth Duplex pump which is attached to the boiler, was working on air, but it refused on steam, so another tear down is due. If I can get it going that will be the third entry. If not, well, there is always next year. Fortunately Keith Appleton recently produced some videos on the Southworths, one of which had a similar problem, so I think that I know where my problem is.
Incidentally, I showed the beam engine, the Trevithick, and the boiler at an exhibition in Melbourne last weekend. Mostly well received. But I had a succession of people who said of the beam engine “very nice. Except for the cap screws.” When it reached 6 separate commenters on the same theme I was starting to suspect a conspiracy from these rivet counters. Yes it does have cap screws as the main fasteners. And no, they are not true to the period (late 19th century). But I quite liked the look of them. But, one does prefer approval in preference to criticism, and after this concerted barrage of criticism, I relented, and spent a couple of workshop sessions swapping out the cap screws for studs with hex nuts.
The before. With cap screws.
After the upgrade with studs and hex nuts. Was it worth the 2 workshop sessions?
Sometime soon I will paint parts of this engine, and apply wooden lagging to the cylinder.
These shots were sent in by reader Russ, from Tasmania. He reckons that he will tidy up the shop after retirement…. Ha! Little does he know, that there is less spare time after stopping work… there is so much other fun stuff to do.
Is that a Porsche 924 or 928?
No! Much better! It is a Jensen Interceptor Mk 1. Love that aesthetic rear window. Beautiful Tasmanian landscape. Number plate ablated by me.
Now that is a real man-cave!
I think that I still win the prize for the messiest, dirtiest, darkest workshop, but Russ comes in a close second. Note that Russ is a busy surgeon. Hmmm.
Today I mounted the Southworth boiler feed pump on the boiler base, then started on the pipework. Nothing is tested yet, but it is looking interesting IMO.
The Southworth pump, located behind the hand pump.
The steam supply pipe on the left, and the water delivery pipe on the right. The hand pump and the Southworth pump deliver water to separate clack valves on the boiler. There is yet another clack valve in case I ever add an injector. The water supply tank and connections are yet to be added. I am not planning to install a bypass. Note the displacement oiler for the valve chest.
I tried a new trick to bend the pipes for this installation. I read about this somewhere. Bent a piece of wire to use as a pattern when bending and cutting the copper pipe. Worked a treat!
Looking forward to firing up the boiler and testing the boiler feed pump on steam. If it works OK there will be a video.
I could not induce my Southworth steam powered boiler feed pump to work.
Initially I thought that it was a bit tight, and spent time easing the glands, and slightly deepening the O ring grooves. That took a couple of days. But no luck.
So today I took it to our model engineering meeting, with some tools to perform a tear down, and 2 of our senior members took a close look. After some to-ing and fro-ing, the verdict was that I had reversed one of the steam passage blocks, and machined it back to front. I had mis-interpreted the plans. It was due to not really knowing the rules for rotating a part in 3rd angle plans. Pretty annoying. A 3d view of the part would have removed any confusion. Fortunately the fix was not too complicated. 2 threaded holes to fill, and 2 new holes to drill and thread on the other side.
That done, I re-assembled the steam engine side of the duplex. Hooked up a compressed air hose, and see the result….
This is on approx 10psi air. There is no load, so it is running faster than it would if actually pumping water under pressure.
Next I will mount it to the boiler base, and hook up the pipes. Then there will probably be another video.
This one is interesting. It is located in the basement of a multi storey apartment building, in the centre of a major city, and occupies a car parking space. It is screened off from the other car parking spaces, with security mesh and visual blocking.
In the photos you will see some of Peter’s projects. Woodworking, kids toys, and metalworking. Peter also is involved in model railways.
Nice to see some mess. Must be genetic.
Nice bandsaw! I wonder what the bell is used for. Maybe to warn the other apartment occupants that Peter is about to fire up some machinery.
Heavy duty lathe.
It is obviously used!
A grand daughter will be very happy with that!
Thanks for those photos Peter. It is interesting to see another workshop in confined space. I do wonder how the other apartment occupants respond to woodworking thicknesser noise.
The Southworth steam powered boiler feed pump has many gaskets. I have not counted them, but there must be 15-20. All with many 2mm and 4mm holes.
And in the process of making the machine, I have broken quite a few of them with the multiple assemblies and tear downs.
But, fortunately, 2 of the members of my model engineering club have laser CNC cutters, so extra sets of gaskets has not been an impossible ask. (Thank you Brendan and Stuart!)
So, some time ago I asked Stuart, if it would be possible to attach a laser cutter to the CNC mill. His initial answer was NO. But recently, he changed his tune. He attached a laser head to his 3D printed CNC mill and started producing gaskets on request! So, as is a recent pattern, I am walking in Stuart’s footsteps, and I have purchased a 15 watt laser head on Ebay. Chinese of course.
This is the kit. Cost $AuD146.
And this is the 15w laser head. Now I have to work out how to attach it to my mill. Shouldn’t be too difficult, as long as I don’t turn on the spindle while it is attached.
My CNC mill, during the electronics upgrade. Most recent photo. Soon to have a laser head.
Stuart assures me that Mach3 can be configured to operate the laser…. turn it on and off, move the axes at an appropriate speed, etc. I think that some trickery is involved.
With book reviews and OP’s workshops on this blog you might be wondering if anything is happening in MY workshop.
Well, yes.
I have been beavering away, making parts for the Southworth steam powered boiler water feed pump. Today I made the final parts. The machining has been fairly basic and straightforward, so no special photos or videos.
These are the parts and assemblies. Top is the steam cylinders left, the water cylinders right. The water pump stack not attached. The the tails for the valve rods, the valve rods with valves attached, the cylinder caps, the valve rod levers, and some of the gaskets.
I will make a separate blog about the gaskets. These were all laser cut. I will never hand cut another gasket. Laser cutting is cheap, fast and accurate. Way to go!
The valve levers and fittings. These are small, precise, and accurate. Quite a pain to make, even with CNC. I remade more than one of these, due to dropping and losing the original. The fasteners are M2, and not finalised. The off centre drilling of the left hand fitting is of no consequence (I hope).
The valve rods, M2.5, and valves. Cutting those threads, 2.5mm diameter and 25mm long, was also a challenge. I learnt about fixed steadies, but too late to use on this job. Subject for a future blog.
And some of the cylinder end caps. There are 8 altogether.
So now that all of the parts/components are made, I will commence the assembly, then the timing of the steam engine component. Watch this space.
Book review of “A Military History of China” coming up soon. Quite an eye opener.
If you have not sent in photos of your workspace, please do so. The series has generated quite a lot of interest.
Most of the workshop pictures so far have come from Australia, and one from UK. This one is from Holland, sorry Huib, the Netherlands.
Interesting differences. Huib built his own workshop, and he has some nice gear. All of these photos came upside-down. Funny how they consider Oz to be “down-under”. Obviously their reference points are wrong. THEY are the upside-down ones. I mean, we are walking upright, right? They must be upside-down!
Hello John,
Here finally my contribution to your workshop series, as always I might want to show and share too much with others, that’s why I want you to show what you can support and is in line with the possibilities you have on your blog.
See if you can make one blog part of it or cut it into pieces. That’s up to you. I transfer the pictures with WE TRANSFER to you, as it is right you got a mail with the link to download the pictures.
It looks like the pictures that it is all clean and tidy maybe but appearances are deceptive, most of the time it’s not so tidy for me either, for the pictures I cleaned it up.
I have tried to be as complete as possible but if there are any questions please let me know.
I built the barn myself, so as the floor plan was drawn. First I built room 1 which is completely isolated and where I can work during the winter, there are also the most expensive machines.
Later on I built room 2, to store also the wood for the stove. Finally, 5 years ago I built room 3, the largest room where also other things are stored as only hobby stuff, also our bikes and everthing els.
Room 1 is the room where I stay most in, coarse work I do room 2, such as sawing, sanding and coarse drilling. In room 3 I mainly do business that need some space, the large, homemade workbench is a good tool for that. And as you can see, I can’t throw anything away and I keep everything I think of that can be useful in the next hundred years.
The photos contain references to the machine and the space where they are located.
I hope you like the total information.
Kindest regards
Huib
The thing about Holland, is that they HAVE to make the world’s best pumps. Otherwise they are under water. Much of the country is below sea level.
Now, that is nice!
Ahhh!
Ahhhhhh!
Nice! But I will stick with CNC.
Huib also sent a video of his steam plant. Unfortunately I do not have the space to post it, but if Huib can remember the YouTube address I will include that later.
Storage is always a problem no?
So, thank you Huib, for sharing your workplace with us. It is very interesting to see how other model engineers work, and their equipment. I have posted only a fraction of Huib’s photos, due to space limitations. I hope that the chosen shots are of interest to my readers.
ps. Huib, I found the YouTube video…Very nice work!
No hesitation about this one. It is magnificent. A big, expensive, superb book. Very detailed. Lots of photographs, maps, diagrams, plans, tables. And written by people who really know their subject. All naval architects. Very readable, but probably not in one session. In fact, I have read it, selecting sections almost at random, then finding it very difficult to put down.
Here is my official review.
BATTLESHIP BISMARCK- A Design and Operational History
By William Garzke, Robert Dulin and William Jurens.
This superb book, IMO, is destined to become THE authoritative account of conception, design, building, brief naval history and destruction of one of the most famous ships ever. Written by expert naval architects, the 610 pages of double column text are illustrated by many original photographs, maps, and diagrams.
I suppose that some people will read it cover to cover, but I found myself being drawn initially into the design and building of the massive battleship. In a later reading session, I read the incredibly moving accounts of the German survivors. And in another session, the sinking of the Hood. Then, not necessarily sequentially, the chapters leading to the discovery of Bismarck, the disabling of the rudders, and the final, fatal confrontation with the vengeful Royal Navy.
Recently we have been treated to magnificent Seaforth publications of books of plans of warships Helgoland, the Repulse and others. I confess that I was slightly disappointed that similar detailed plans of the Bismarck were not included in this publication, but I understand that there are limits. Perhaps a separate book?
Congratulations to the authors and publishers of this magnificent work, which I am delighted to add to my library.
Some pics of the book.
At £55 it IS expensive. But in this case you get what you pay for.
Now this is a workshop where I would feel at home…..
“Hi John some photo’s attached.
I work in my double garage 56 square meters. I have been self employed for the last 30 years but have reached the stage where I want to retire, some of my customers still send me jobs to do which I cannot say no to so it keeps the hobby going.
I have a Bridgeport copy converted to 4 axis CNC running Mach3 using MachStdMill screen set (love it).
My lathe is a Prototrak SLX on a King Rich lathe bed ( toolroom quality).
Misc other machines small surface grinder,tool & cutter grinder, compressor, 15 tonne press, bandsaw,welding gear electric & oxy acetylene, overhead crane ( 250kg capacity )
I am running out of space.
I am close to finishing my boiler will send some photo’s soon.
Cheers
John”
Thanks for the pics John. A bit of gear envy happening here. Love the gantry!
I am starting to regret asking for the workshop photos. Another reader, John, has sent in photos of his super organised, super clean workshop. We must admit that it looks quite inviting,….
and fairly safe, unlike my disorganised dirty mess.
Here are the photos. Somewhere in Oz.
And some notes from John….
“Thought you and possibly your readers might enjoy some pics of my ‘shop. All crammed into a two car garage! I really am running out of space and have to try and be as efficient as possible in that regard . Note the ladders etc hung on brackets from the ceiling in one of the pics. I also have an anvil and coke forge outside, plus materials, bolts and the like stored in one of the garden sheds outside the workshop.
A few notes to go:
103350 my ML7 Myford lathe lives behind the large red tool chest which is handily placed to mill and lathes. Parts washer (green lid) to right of pic, under cloth foreground is completed riding trailer to go behind current long term project 2 ½ “ Burrell traction engine. In welding area, BOC Industrial MIG, Unimig plasma cutter sitting on top, orange cabinet is sand blaster. Note also the copper pipes across the ceiling – they run across and back to help cool the air and dehumidify, with droppers and drain cocks at various locations, plus there’s two inline filters (one to 3 micron) to help ensure dry air for spray painting and sand blasting.
103407 ac/dcTIG, folder/g’tine/rolls (blue in corner), new welding/fab bench frames under construction on floor by current welding bench.
103450 press, tool and cutter grinder, bandsaw, oxy, compressor.
103575 mill, drill press and two grinders/linisher.
103558 ML7 – my first lathe
103633 bench area, tall grey cabinet holds lots of gear – taps, dies, tooling, roatab, dividing head etc etc
104041 recent mods to compressor to quieten the beast using an old Holden red motor air cleaner. Replaces the small plastic jobbies that screw into the heads. It’s been quite effective.”
So, thank you John, for further magnifying my inferiority complex regarding workshop organisation. And I know that these machines are put to work, making a traction engine, and currently a beam engine. Plus a full time job, unlike this retired medico who has time to kill.
Dear readers, if anyone has a dirty, disorganised, dark workshop, please send me some photos. It will do wonders for my self esteem.
As I reported on Sep 3, I was recovering from a decent dose of influenza, and feeling a need to do something after almost 2 weeks of inactivity, and I decided to put some more paint on the Trevithick dredger engine. After all, what could go wrong? Just a bit of gentle painting.
I was quite proud of the job. No paint spills. No brush marks on neighbouring items. No brush hairs in the work, and minimal brush marks.
I wondered how long I would need to wait between coats, so I checked the paint tin.
O shit! I had used the wrong paint….
I had used the epoxy enamel instead of the high temperature resistant Pot Belly Black! The brain had apparently not recovered fully from the ‘flu.
I decided to sleep on the problem. Checked with my resident paint expert (SWMBO), and on her suggestion, next day applied some mineral turpentine. The paint was dry, but the turps did seem to soften it. So I applied some more turps, then attacked the epoxy paint with a rag.
To my delight, it mostly came off. I was not too bothered by the paint in the deep cracks…. that could be a filler.
Then I carefully dried everything, another rub with clean rags, and applied another coat. This time using the correct paint. 2 coats.
Reader Huib asked how it had all eventuated, so today I took some pics of the engine in its current home… our kitchen. The budgerigars are SWMBO’s decorative touch.
The kitchen is due for a renovation. I made those cupboards and benches 30 years ago.
But the paint job looks ok hey?
Another view. In the background is a painting of a dog training group in the grounds of the MCG, by Samantha Lord.
Hey readers (male and female), waiting for more workshop photos to post. It doesn’t have to be the whole workshop…. just a photo of your favourite machine would be great!
After reading this book, cover to cover, in 2 days, I felt that I had a real grasp of the reality of the 1899-1902 war which so shaped South Africa’s history. I now realise that my previous knowledge of the war was very sketchy.
The 100 iconic objects which are held in the War Museum of the Boer Republics, and 200 other objects, maps, and many photographs, are beautifully presented in this high quality book of 260 pages. The story of each object is told in short essay style by gifted, expert writers.
The many subjects include battles, weapons, military personalities, politicians, places, civilians, equipment, prisoners of war, concentration camps, costs of the war, and longer term outcomes.
The book does not glorify the Anglo-Boer War. If anything, it is an anti-war treatise. It certainly has had a major impact on this reviewer.
I am progressing my Southworth pump. Today, Stuart brought his completed version, so I photographed the incomplete and complete versions together. Actually, it was very useful to see Stuart’s pump again. An obvious difference in one of the components made me realise that I had made a mistake. Now rectified.
Optimum mill, Chicago compressor “very quiet”, Myford Super 7 lathe, drill press.
Optimum 6″lathe, drop band saw, linisher. Plenty of light. No swarf on the floor (no snakes apparently).
And from Victoria Oz, Neil sent these shots of his workshop, with some work in progress visible…
Reading Neil’s signs reminds me of a sign which I saw on someone else’s mill or lathe… “Not to be operated by fuckwits”. Maybe I should put up such a sign on in my workshop, but then, it might invite comments about the current occupant.
And finally, my friend and mentor Stuart’s workshop…
This is Stuart’s kitchen, which he is putting to the best use! Note the laser cutter, which will cut metal up to 1mm thick, and the optical comparator. But does the laser slice the toast, Stuart?
Stuart’s actual workshop is the garage. The car, very sensibly has been expelled to the outside. Note the Boxford CNC lathe (the same as my Boxford CNC lathe), and the old green manual lathe on the back wall, still gets a lot of use. Disgustingly neat and clean. Starting to get a complex about this.
And in the other direction is Stuart’s CNC mill (blue base), CNC router on the bench.
And finally, I decided to add a shot of the spare bedroom in my home. Note the Boxford CNC lathe,
This is the spare bedroom in my house. You are welcome to stay, after moving some stuff.
My Boxford CNC lathe in the spare bedroom. Well, no-one comes to stay very often!
Another view of the spare bedroom. 2 Boley jeweller’s lathes. They do occasionally get used.
And another view of the spare bedroom. Plenty of bedtime reading. And another jeweller’s lathe in case you get the urge in the middle of the night.
So there you are. Please send your photos of your heaven on Earth.
This post was inspired by one of my readers sending me some photos of her workshop. The photos grabbed my attention for several reasons.
Firstly, the metal working machines share the space with tomatoes! Unusual, eclectic use of the space. Secondly, the roof and walls are made of glass! Great for natural lighting, and nice views for the machinist, and possibly the neighbours. Thirdly, it is such a small space, requiring planning to accomodate quite a few machines and work space. And fourthly, it is so neat and clean. I do see an occasional bit of swarf, but it is so unlike the mess that I work in, that it is quite striking to see such a clean workshop.
Thanks to reader Jennifer for sending these photos. For obvious reasons I will not publish further location details except to reveal that the location is in the UK.
Jennifer tells me that it is all double glazed, and is open to the living area of the house, so it is heated. Apparently it never becomes too hot in summer.
And as a complete antithesis, this is my main workshop in Oz. Bigger, messier, dirtier, darker. Actually, when I looked over my photos I could not find one decent view of my workshop, so I took some new pics. Needless to say, there was no special tidying for the photo.
It is a tin shed, unlined, but does have a wood heater. This view takes in about 2/3 of the area. There are 3 lathes in this shot. Can you see them? CNC lathe in foreground. Also my CNC mill on the right. There is also a tool and cutter grinder, vertical bandsaw, drop bandsaw. And lots of ancillary tooling.
And a pedestal drill, 2 linishers, grinder, and part view of the drop band saw. The anvil gets quite a lot of use. It is mounted on heavy duty wheels so I can take it to the job.
My workbench in the foreground, A very heavy cast iron setup table (blue) with granite surface plate. Shop made ring roller centre.
So, that is where I spend most of my waking hours. The shed started life as a farm workshop, where a lot of welding, and repair and maintenance of farm machinery was done. These days it is mainly used for model engineering. In my working life I was an obsessively neat, organised and particular surgeon. Not quite sure how my activities ended in this mess. But you know what?… I feel totally comfortable here.
If you have some photos of your own workshop area, please send them in and I will publish them for the interest of other readers. Big areas, small areas, old machines or new. Show us where you spend your most enjoyable hours. Send them to me at jviggers@iinet.net.au
Today is the first day since I became sick that I have felt able to drive. Until today I have been experiencing coughing paroxysms, severe headaches, dizzy episodes, even 2 episodes of hallucinations which were really weird. Also requiring pain killers regularly.
My GP thinks that I have had influenza A, despite vaccination earlier in the year. Certainly the nastiest bug which I have encountered in many years.
But as today warmed up, and I had not required any analgesics, and the coughing was settling, I decided to visit my workshop. “Visit”, rather than operate machines. I suspected that my mental faculties were not yet 100%. It is a 20-25″ drive to my workshop, so off I went.
I was pleased to note that my neighbour had mowed the grass around my sheds. It had become quite thick and high, and with the warmer spring weather today, I was not looking forward to walking through the thigh high vegetation which could conceal nasty poisonous fauna. The neighbour has long term loan of my tractor and slasher, and the quid pro quo is that I get my grass mowed whenever required.
So what to do, not requiring turning on potentially dangerous machines? I decided to look at the Trevithick dredger engine. It has been waiting for some painting. That would not be too arduous or too dangerous!
The engine end of the boiler was waiting for some flat black paint. So I removed some appendages, filed and wire brushed the surfaces, and washed them down with mineral turps. Found the paint, stirred it thoroughly, and carefully applied it with some small, new brushes.
The engine end of the machine, with one coat of the flat black applied. Hmm…. I don’t remember it going streaky like that before….. Maybe the second coat will look better.
I used the paint to touch up some other areas also.
Then as I was cleaning up, before going home I took another look at the paint can.
O shit! I had used the wrong paint can!
I should have used the “Pot Belly Black”. Somehow, I picked up the other one. The “Rust Guard Epoxy Enamel” is good paint, but it might not tolerate the surface temperatures of the boiler. And an etch primer is recommended for it, which would explain my application problem.
So what to do? I know that most of you will be screaming at the screen, to strip off the epoxy paint and start again. But, for better or for worse I have decided to apply another coat of epoxy tomorrow and see if the appearance improves. I expect that it will. Then a trial firing in a few days will demonstrate whether the epoxy will cope with the temperatures. If it copes…. fine. It is well away from the furnace. If not, then a very time consuming strip job and repainting will be in order.
It seems that my mentation has not fully recovered.
About a week ago I felt a bit off, headachey, but I had just driven through Melbourne peak hour traffic, so was not too concerned.
But the next day my head was going to explode, my chest ached, my skin was painful, and I was experiencing chills and sweats. That has all continued. I assume it is a viral infection, but it is taking longer than usual to start resolving. And now I have started persistent coughing. Might have to see the quack.
So I have not been in the workshop for a week. And I am getting a bit bored.
They are eating a banana handed to them by my wife. The baby came out of its mothers pouch about 2 months ago. If the baby is a female, she will become part of the house fauna. If male, he will be booted out at when about 12 months age.
No, they do not have names. But they do come down when my wife calls “possum, possum”.
We have encouraged this family for many of their generations by not frightening them, and feeding them. Possums live in many Australian roof spaces. They are difficult to keep out, and it is illegal to remove them further than the confines of the property. So trapping and removal is usually temporary.
They entertain us, and visitors. Never cause bother. Well, almost never… they found a way into our pantry once, and raided every open packet of cereal, raisins, etc., throwing the unwanted packages onto the floor. We just looked at the mess and laughed.
A couple of days in the workshop, and the large castings are almost fully machined. Straightforward machining. Made a couple of mistakes, but none fatal. Changing BA fasteners to metric.
The steam cylinders block in the mill vise. Almost complete water cylinders block sitting behind for the photo.
Steam cylinders on right, water cylinders on left. The temporary steel pins are to ensure accurate alignment of the 2 blocks. Water and steam passages come later.
This is the first model machining which I have done since April. It should be second nature, but I admit to a bit of hesitation, nervousness, initially. Especially starting on an irregular, slightly complicated shape like these. But it is all coming back now. And I am really enjoying it.
My CNC mill is now mostly functioning, although several functions are yet to be connected. The main spindle and XY&Z axes are working, and responding appropriately to Mach3 commands from the laptop computer. It has taken longer than anticipated so far, mainly due to difficulty in understanding manuals supplied from Asia. Axis limit and homing switches, oil pump, coolant pump, work light, and cooling fans still to be connected.
So there has been little of general interest coming out of my workshop. Hence no posts on this site. Not that I have been idle.
I disassembled the top slide on the Colchester lathe to discover the cause for excessive back-lash. It was a worn acme thread bronze nut. No luck yet in finding a new nut for this 45 year old lathe. I will have to make one. Meanwhile, I used a quick and dirty trick to reduce the back-lash which I will detail soon.
The top-slide acme screw and bronze nut which needs replacing.
I also cleaned and freed up a 3 jaw 10″ chuck which I bought on Ebay. It was frozen solid, so I soaked it in kerosene bath for a few months. Actually, I forgot all about it while it was in the kerosene, and accidentally rediscovered it. This time, after using an impact screwdriver, I was able to open it up and expose the gears and get them moving. Might be worth a photo also.
The 240mm diameter chuck. I was tempted to buy by the removable, reversible jaws. Thinking that I could make some soft jaws. Trouble is that it is an industrial production line chuck with very little movement. But it is nice and tight. Still deciding. At least I can wind the jaws in and out a bit now.
And I finally got around to installing piston rings in the triple expansion steam engine. Used Viton O-rings. Not a difficult task, and it should not be difficult to replace them from time to time in future. Will be interesting to see if the engine performance improves.
Now to get onto my next project. I have plans and bronze castings for a Southworth design water pump, for replenishing the vertical boiler water while it is in use. It was a surprise to me, just how much water is consumed by a boiler which is powering a model steam engine. To date I have used a hand pump, but having seen a steam powered pump in action, I have decided to make one.
The steam is supplied from the boiler which is being replenished. The pump has to use steam at boiler steam pressure, to force water into the boiler. So the pump has to raise the pressure of the feed water above the pressure of the steam which is powering the pump. The clever pump design uses large steam driven pistons to drive smaller water pump pistons.
Larger steam pistons top right 5/8″ dia, water pistons bottom left 3/8″ dia.
Here is a video of a Southworth pump in action. It was made by Stuart Tankard. Here it is running on compressed air, but I have seen it working similarly on steam. I will be making one of the same design, hopefully approaching this level of finish.
A build of larger version of the pump was described by J. Bertinat in a series of articles “Model Engineer” in 1993 (first article 18 June 1993).
The unmachined castings. Lumps of rough bronze. And the plans.
One of the castings after preliminary machining to establish some faces. The “water cylinders” block. Part no. 6
Fitted the new VSD Friday. Ordered Tues pm. Arrived Thurs am. Impressive.
$AUD315, inc shipping. Job cost is mounting. Still within reasonable limits.
The old VSD, top right. The axis controllers (top left) had not been wired when this photo was taken.
The new VSD (variable speed drive) 4kw. Fitted neatly with some new mounting holes, without any drama. The rats nest looks less daunting every day.
Now, except for the main spindle motor, there are no more original major electrical components. All have been updated and replaced, along with the cables.
Yet to be wired are the VSD, coolant pump, oil feed pump, limit switches, homing switches, and the Gecko driver and 48v power supply for the rotary table. But the mill is useable now. Video coming up soon.
2 steps forward, 1 step back. That’s what this project is experiencing.
The axis servo motors, their controllers and connections to power, breakout boards, and computer connections are complete, and all working.
An old laptop has found a use. Installed Mach3, Vectric V-Carve Pro. And the connections to the Smooth Stepper board. Windows 10. Deleted all non CNC related programs to gain space on the hard drive.
A problem with the main spindle. It is essentially unchanged from the original. Same motor (4kw/5hp 3 phase), same VSD, and same 3 phase power which is supplied through a phase changer, because the property has only 2 phases supplied. When powered up, it worked, but the RPM’s could not be altered from a very slow rate. The controlling voltage from the breakout board was not changing despite changing the inputs. ? due to a problem with the settings, or a faulty BOB. Didn’t seem serious.
So I was a bit surprised when later I switched on the mill, intending to change some settings, to hear 2 significant pops, and to smell that disgusting burnt electrical component smell, with smoke coming from the electrical enclosure.
Quickly shut everything down, and waited for the cavalry to arrive.
Stuart found that a 24v power supply had failed. No big deal. Not an expensive component. Maybe got a short circuit from a bit of swarf? But further inspection revealed that the VSD had also failed. A capacitor and diode burnt out. ? caused by a surge from the failing power supply? Repairable, but I decided to buy a new VSD. The failed VSD is probably as old as the mill (24 years), so it had a pretty good run. If the old VSD is repairable, it will serve as a spare.
Meanwhile, as a consequence, the main spindle is not working. I have a list of jobs that I want to get into, particularly the steam pump for the vertical boiler. So I will reattach the high speed spindle and use that. It is 2.2kw, but uses high revs to develop power, so I will be limited to small end mills and drills, until the new components (VSD and power supply) arrive. The high speed spindle is single phase, and the speed control is manually selected. Not quite as convenient but useable for the time being.
While Stuart has his head buried in the electrical enclosure, I have been his gopher and TA. But also fitting in a couple of other jobs which have been on the “to do” list for ages. Like clearing out rubbish from the workshop, tidying up etc.
One task which has been vexing me, was to remove a sheet of flooring board which was under the Colchester lathe. The sheet was originally placed under the lathe to protect the vinyl floor covering, but it was not a good decision. As the flooring board became wet with cutting oil and coolant, it would swell and shrink, and I was aware that the lathe levels and settings were changing. So I decided to remove the sheet of flooring, and let the lathe feet sit directly on steel pads on the vinyl/concrete floor.
But how to remove the sheet of flooring from underneath the almost 1 ton lathe? The lathe was originally placed into its rather tight position with a forklift, which is no longer available. The wooden sheet was the same size as the base of the lathe.
So I made these…
The bolt adjusts the height of the jack.
From a piece of scrap I-beam.
I used a crow bar to raise the corners of the lathe enough to place the jacks into position. A bit of trial and error to get the heights correct. When the lathe was about 25mm clear of the flooring, I pulled the sheet out. Then used the crowbar to remove the jacks, and lower the lathe onto its base plates.
I will reset the lathe’s screw feet in the next day or 2, using a precision level and test cuts. There was an excellent YouTube video by “This Old Tony” on the subject recently.
Not much more to report today, but I have decided how to position the computer.
Not easy, because the computer needs to be protected from flying swarf and coolant spray from the CNC mill and the manual mill which is immediately adjacent. And I want the computer to be close to the machine. The CNC mill is NOT in an enclosure.
So this is what I have decided….
The laptop is just low enough to reach while standing. The E stop and other buttons are underneath.
And if the swarf is really flying, I can turn the PC away…
Might need some adjustments. The laptop is an old Dell ATG. Said to be resistant to fluids and relatively resistant to shock/vibration etc. Military specs. I might add some side protection and perhaps a roof.
I have been putting quite a few hours into the upgrade, but not much to show photographically.
Finally got the new servo motors installed. Replaced the X axis belt. The most difficult servo to access was the Y axis, and of course that was the only one where the alignment of the timing belt was out. Finally sorted by using a fibre optic camera to see why the belt was climbing onto the flange of the pulley. The pulley was 1.2mm too far onto its shaft. I know that, because I solved the problem by inserting washers under the motor mounts. 1mm washers did not work, nor did 1.5mm washers. But 1.2mm washes did work perfectly.
Today Stuart arrived and removed more of the old wiring.
Stuart, doing another CNC upgrade wiring.
The old 7k computer has been removed, leaving some buttons. I might be able to use those. The computer enclosure might disappear too. Not decided yet.
The old CNC mill has lost some weight. Those cartons are full of old parts. Note that the floor has been swept. Stuart was concerned that we might be infested with snakes, but it is winter here, so we should OK until the weather warms up.
I removed the old XY & Z axis servo motors from the mill. Each one weighs about 15kg (33lb).
The old servo motors. The X and Z were working fine. The Y was faulty, but I do not know whether the fault was in the motor, the encoder, the controller, or the connecting wires. I will put them on Ebay as 2 working, one for parts.
Then I removed the belt drive pulley off each motor. There was a grub screw, which would not budge. Assuming that it had been Loctited, I applied some heat, judiciously. The grub screw came out, but the pulley would not budge, so a little more heat, and a gear puller. Two of the gears came off, but one still would not budge.
I asked for advice, and I was loaned a different type of gear puller. (thanks Rudi). This time, some movement of the gear on the shaft was noted, and eventually the last motor gave up its gear.
This one worked.
The shaft of the old motors was 16mm diameter. The new motors had 19mm shafts. So I spent some time on the lathe boring out the gears to fit the shafts of the new motors. The keyways of the old motors were 5x5mm, and the new ones were 6x6mm. So, I borrowed a 6mm broach (thanks Stuart), and enlarged the keyways in the rebored gears to 6mm width. The new keyways needed a lower profile, so some time on the mill and surface grinder to reduce the thickness of the keys to 4.5mm.
That was quite a few peasant hours hours on the lathe, mill, and surface grinder, but the end result was good.
The new servo motors, with the timing belt gears fitted, with keys in place. I will set each motor in place on the CNC mill, determine the final exact position of the gear on the shaft, then indent the shaft for the grub screw. Then, when I am sure that all is correct, the gear, grubscrew and shaft will be Loctited.
Another small issue was that the boss on the new motors was 5mm deep compared to 3.5mm deep for the originals. So the mounting plate for each motor needed the recess to be deepened by about 1.5mm.
I used a boring head on the mill to deepen the first one, but it did not produce a good finish, so the next 2 (shown) were deepened on the lathe, in a 4 jaw chuck.
Meanwhile, back to the rats nest in the electric control enclosure….
The bare space top left is where the old servo controllers lived. They were removed. Then I spent a half day tracing each wire from the controller to the old servo, and removing it. That produced a carton full of wires. The rats nest is now a little less tangled. A lot more of those wires will be removed as the job progresses.
The new servo controllers bolted into position. They are fatter than the originals, so a bit of rearranging was required. The yellow box top right is the main spindle speed control (VSD) which is being retained.
And on the right hand side, newly bolted into position today, from the top down, are the smooth stepper, the C11 breakout board, and two C10 breakout boards. Awaiting some expert wiring. (Stuart, are you reading this?)
this is the new Y axis servo motor, sitting on its mounting plate, after the old servo has been removed
Unfortunately the existing M8 threaded holes in the mounting plate are just in the wrong position for the new motor’s 8mm mounting holes.
So, do I 1. make a new mounting plate and assembly? 2. machine or file the new motor’s holes to fit the old plate? Or 3. Fill the old mounting plate hole, then drill and tap new holes in the correct position ??
seemed a lot of work 2. would have looked ugly and probably voided the motor’s warranty 3. Seemed tricky, but I decided to give it a go. If unsuccessful I could always revert to 1.
Filling the old holes. Could have used steel thread and silver soldered it into place. In retrospect, would probably have been the best option. Could have used steel thread and Loctited it into place…. decided against, in case subsequent machining softened the Loctite. Could have filled the old holes with bronze, and drilled and tapped new threaded holes…. well, for better or worse, that’s what I decided to do.
The new holes impinged about 25-33% on the old holes.
The old holes were bronzed. I improved my technique as I moved around the holes.
After cleaning up on the mill, the new holes were center drilled
Then drilled to size, and tapped. revealed that the bronze did not entirely fill the voids.
I wondered if the bronze would accept a suitable degree of tightening of the M8 cap screws, but all seemed fine. Note the jacking bolts, to prevent distortion of the weldment in the milling vice.
The bronze-steel sandwich did cause the tapping drill to wander slightly, but not enough to cause concern. Next time I will try silver soldering in a steel filler piece.
Meanwhile, I have been removing parts and wires from the electrical enclosure.
The servo controllers are removed. Bit of a rats’ nest hey! About 90% to go…
I neglected to take a photo of the completed gear. In this shot it is almost finished.
I intended to reassemble the spindle and its cluster of gears, spacers, and taper roller bearings myself, but after talking to an expert on the topic (Swen Pettig), I realised that sometimes it is better to leave surgery to a surgeon.
I gratefully accepted Swen’s offer to help. In his working life Swen had performed this task on many, many occasions.
Firstly Swen reinserted the taper bearing outer races in the headstock. The lathe spindle is approx 80mm diameter and 800mm long so it is heavy. After careful cleaning, it was fed into the headstock, progressively loading the bearings, gears, spacers, clips and nuts, and moving and tapping them down the shaft as it was moved into place.
Note the photo prints to remind us of the order of reassembly. Board to protect the lathe bed. Repaired gear laying flat. Surgeons’ towels blue rags.
when it was all reassembled and tightened, the retaining disk at the chuck end was loosened, sealed with liquid gasket (Loctite product- cannot remember the name), and retightened.
Then Swen went through a lengthy process of checking the end play, using a dial indicator, tapping each end of the shaft with a copper hammer, and finally settling on 0.01mm of play.
Then we had a short test run at low speed, and he tested the end play again, with no change.
Then we set it running at 200 rpm, and went and had a cup of coffee for 20 minutes. Came back and checked the bearings temperatures. All cold, all good.
I reinstalled the external gears, the cover, etc, and took some decent cuts in some cold rolled bar.
Seaforth Publishing, in association withThe National Maritime Museum Greenwich, is publishing a series of books of plans and history of famous warships, in this case the Helgoland.
GERMAN BATTLESHIP HELGOLAND
Detailed in the original builders’ plans
By Aidan Dodson
Wow!
I opened this large format, hardcover book of ship plans at midnight, expecting a quick flip through, and was able put it down 3 hours later. But I will be returning.
The first 20 pages outline the development of German dreadnaughts and their wartime careers and fates, and a fascinating history it is. The ship structure, armament, machinery (including engines), protection, pumping systems and damage control, and fire control are described in a degree of detail which was satisfying and not overwhelming to this non expert but interested reader-reviewer.
Then, all but 20 of its 144 pages are reproductions of the original builders’ plans of the WW1 German battleship Helgoland. The plans are detailed, and beautiful and fascinating. With original annotations in German, translated and explained in the margins. The 940 x 290mm centre fold of the longitudinal section is just stunning!
Modelers, historians, ship aficionados, and anyone with a vague interest in battleships will love this book. I certainly do, and eagerly await further volumes in the series.
Front jacket
Centerfold.
The German navy used triple expansion reciprocating engines rather than pay royalties to Parsons to use turbine engines.
The major components arrived this week, from China and USA. Switches, and other components which go “ping” will be bought locally as required. I am hoping that existing pulleys, belts, brackets will be adaptable.
The motors to drive the X, Y and Z axes are 1.2kW AC servo motors which can be connected to single or 3 phase power. Each one weighs 6.7kg (14.7lb) . From China, they are nicely finished. Substantially shorter than the old servos which they are replacing and slightly larger diameter. I am hoping that the slightly larger diameter will not cause major problems.
AC servo. There are 3 of these. Kitchen knife to open the box and for scale.
Old Y axis servo on the right, and the new AC servo left.
And each servo motor came with a controller and cables and connectors.
And the electronics came from USA.
C11 breakout board.
C10 breakout boards x2
And the Smooth stepper control board. It is tiny, but the most expensive electronic component.
All up cost so far is ~$AUD2100, of which shipping is about 25%.
Next step is to swap over the servos. The old shafts are 16mm and the new ones are 19mm. I intend to machine the bores of the pulleys. Hope there is enough meat Tofu to allow that.
Today Swen and I started cutting the gear. Here is the setup.
The gear was centered on the rotary table with an aluminium bush, which fitted the outside of an ER40 collet chuck. The chuck had an M3 shaft which fitted neatly into the spindle of the rotary table. 3 bolts secured the gear blank to the T slots on the rotary table.
This photo was taken after the setup was broken down. Showing the M3 taper ER 40 collet holder, which I used to centralise the gear blank on the rotary table.
I started the mill conservatively at 200 rpm and a 0.5mm deep cut, but gradually increased the RPM to 450, and the depth of cut to 2mm. Later adjusted to 300rpm, 1mm cut.
The CNC table performed flawlessly, with rapid advances between the 360/77º degree cuts (about 4.6º each tooth). The feed rate was controlled by manually winding the X axis feed on the mill.
We initially used water soluble cutting fluid, but changed later to raw Tap Magic, which seemed to work better.
As you can hear in the following short video, the cutter teeth are slightly off centre, but working well. Didn’t quite finish the gear teeth in this session. Some sparks later on, indicated that a cutter sharpening was required before the finishing run. That will happen tomorrow.
The smoke is evaporation of cutting oil.
The setup will be left undisturbed by removing the gear cutter for sharpening.
I changed my mind about sharpening the cutter in the middle of the job, and continued cutting.
Instead, I lowered the spindle rpm, and the feed-rate. The sparks stopped. Maybe I was just pushing too hard, or maybe there was a hard spot in the metal. Anyway, I finished the cuts.
The finished gear cut. Are those teeth looking a bit skinny at the peaks?
Showing the setup from the operator’s view. The CNC table worked brilliantly.
Removing the burrs with wire brush and file.
And testing the fit with a trial run in the headstock. Thanks Swen, for helping (actually directing) the trial run. The new gear on the left.
I made a video of the gear being rotated through 360mm, perfectly, but for some reason it will not upload. (did upload eventually.. see below). It looks perfect, with a tiny amount of backlash. Full installation in a day or two. I was quite surprised that making the gear to the specifications worked so well.
Me, testing the backlash.
And afterwards, sharpening the cutter on the Quorn T&C cutter grinder which I made a few years ago. An amazingly versatile tool.
Just in case I need to make another.
The lathe headstock will be properly reassembled in a couple of days. But I am finally feeling a bit confident about this job.
For those readers who have not automatically skipped this post after reading the title, I had some time to spend on Google Earth Pro recently, and back to my area of interest, at the big black reflective rectangle 22 x 7km, photographed in 1999. And the strange 300 x 150mm objects seen 2006 – 2007.
This time I went back a few years to 2002, and this line of objects caught my eye.
This is Antarctica, Dec 31 2002. The red, yellow and blue pins are 300 x 150m objects, seen 2002-7. The big black rectangle is in the middle of the left hand cluster. The area of today’s interest is the small red line to the left of the long red line. The small red line, placed by me on the photo, is 20km long. The next photo is zoomed in to the small red line…
Still 2002, small red line. Those 21 black dots are 1km apart. And there is another, to the right near the top of my red line. Now to zoom in some more…
Look at those shapes. They are 300 x 300m each. Similar but not identical to each other. Exactly 1 km apart.
The black rectangle does not appear in these 2002 photos.
The co-ordinates are bottom right, so you can check this out for yourself. What do those black shapes look like to you? Unfortunately zooming in closer does not increase the clarity.
Now, do you want to know how I found this second row of objects? This is where it gets even more interesting.
There appears to be a track or mark in the snow leading away from the big black rectangle, leading to the south east at heading 112º. The track is 7km wide, the same as the black object. I followed it on Google Earth, until it disappeared after 132km. At that point on Google Earth I scanned the years 1984-2016. And zoomed in and out.
And guess what! That point is exactly where the row of 21 objects which are 1km apart, starts (or ends). WTF?!
And just to complete this post, there is a site on YouTube which I have been watching with interest, called “Bruce Sees All”. “Bruce” is an amateur astronomer with a decent telescope which he has been pointing at the moon, and making videos. I have taken some screen shots, which I post here. Hopefully this will stimulate some of you to go to the YT site and check it out for yourself.
No scale unfortunately, but that white donut shape must be many kilometers wide. And by the shadow which it is casting, it is way above the surface. Similar shapes nearby.
And look closely at all of the rectilinear shapes in this screenshot. Square meteorites perhaps?
I will get back to gear making tomorrow, hopefully.
Almost ready to cut the lathe gear. It is 237mm diameter, 25mm thick, with a new rim Loctited and Scotch pinned to the old hub.
I borrowed the 6-12″ Mitutoyo micrometer from a GSMEE member. Thanks Rudi. I had to learn how to read an imperial micrometer. The rim is glued and pinned to the original hub.
And today I made a tool holder for the new-old gear cutter which I purchased from Russia. It was meant to have a 27mm bore, but when measured was closer to 27.1mm, so I made an arbor to match.
The cutter on the new arbor. It required 2 attempts to get acceptable dimensions. It will be held in the vertical mill with an Er40 collet chuck. It runs true. Not bad for an ex gynaecologist hey? Might need to sharpen the teeth on this old-new cutter.
Meanwhile, on advice from Swen, another GSMEE member, thinking ahead, and setting up to trial fit the new gear after it is cut. Here is Swen, making some steel temporary bearings to try the new gear on the shaft, after the gear is made. Tapping out the old taper bearing races. This is what Swen did for a living when he was in the work force. I have learned heaps just watching Swen doing his stuff.
I admit that I would not have been brave enough to do this. “Piece of cake” says Swen, tapping out the race with a copper drift.
Tidied the parts with a file and belt sander.
johnsmachines 