johnsmachines

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"

In Search of an ELEVATING MECHANISM

“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.

Oh well. The tour was enjoyable.

Making a Scale Model Wooden Slide and Carriage for an Armstrong Cannon

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.

Armstrong RML Wooden Chassis – 3

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.

Armstrong RML Wooden Chassis – 2

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.

Armstrong 80pr Cannon Wooden Chassis

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?

Armstrong 80pr RML – another one!

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.

Reconditioning a Tandem Trailer

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.

It will probably outlast me.

Making a JCB 3CX Slew Lock Plate

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

Deep V fillets were ground, and MIG welded.

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.

JCB CX3 Backhoe Cylinder Seals

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).

JCB 3CX 4×4. Next project?

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.

An Engineer’s View of Ancient Egypt. (Book Review)

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.

Cost about $AUD30 from Amazon Books.

Can’t wait to visit Egypt.

3D Printer Upgrades. Are They Worth It?

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….

  1. 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.
  2. An all-metal fully geared extruder. $AUD25
  3. 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.

2 Man Tongs

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 place
Testing 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…..

RETAIL THERAPY for LOCKDOWN

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.

3D Printer Enclosure

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.

Getting close to the first big bronze pour!

How to Pour the Bronze Barrel?

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.

Lockdown No. 5

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.

3D Printing Difficulties

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.

Kant-Twist Clamps

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 Bit Sharpening Jig

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.

Armstrong RML Cannon Sights

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 hole
Fabricating 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.

G Codes for CNC Lathe. Ezilathe.

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.

How I Made a Complex Model with NO PLANS. For Pramad Agrawal.

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.)

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. 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.
  7. 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.

  1. 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.
  2. 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.
  3. 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.
  4. 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.

GSMEE Meeting 23 June 2021

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.

A Bit of a Break

No posts for a couple of weeks.

I am taking a break, after experiencing a break.

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.

So that is my excuse for no posts for a while.

800 POSTS. A list of all of my titles.

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.

PostsAdd new post

Solid Copper Riveting. What I have learned.

Final Lasering on Armstrong RML model cannon

3D Printer Plate Adhesion Problems

Armstrong RML model No 2 Finished!

Bronze Casting a model Turkish Bombard-1

A Visit to an Old Friend

Cheap Epoxy Metal Repair/ Filler, and Initial Painting Model Cannon

Silo Art Trail

Salt Pans, Sand Hills, Blue Skies.

Bush Camping At Hattah-Kulkyne

2 Model Cannons- Materials and Processes List

Australian Ship Sunk by US Navy

Model Cannon. Last (?) Teardown.

A Dilemma. Wheels or handles for running back the Armstrong 80pr RML Cannon.

Walking Dead Chess Men

Casting Brass Chess Pieces- 2

Pre-teardown Model RML Cannon

SWMBO Break

Chess Men. Next step, make a tree

Painting a Brass Label

Chess. 3d printing complete.

Now, THIS is a SHED!

3D printing a PLA chess set for alu/bronze casting

Chess

I have a brain

Operating Manual for 80pr RML Gun.

Setting Elevating Gears on the Armstrong 80pd RML Model

Book Review. “….Royal Gun Factory….”

Where to Make a Cannon? R.G.F.

A Useful Book. How to Make A Cannon.

Motorising a Mill-Drill Table

300pd Blackpowder Cannons at Williamstown

Elsternwick Armstrong 80pd RML’s

Hygrometers, Humidors, and a bit of model cannon stuff.

Battery Point, Port Fairy, Victoria, Australia.

A Session on the Ring Roller

Old Photos of Armstrong RML’s

Armstrong 80pr RML’s at Portland, Port Fairy and Warrnambool.

A (model) Cannon for Christmas

Aluminium Bronze

Who Would Like a CANNON for Christmas?

Wooden Base for Model Cannon

One down, one to go.

Pointy Projectiles

GSMEE Annual BBQ

Assembly Modules

Painting Covers a Multitude of Sins

Not One of my Skills…Riveting

Warts and All

Model Cannon. Final Photos before Teardown

Sights Set On Completion

Gunners Platform

Fitting the Loader.

Pruning Trees. And how to remove investment plaster from castings.

33.9/34 Not Bad.

A Record for Number of Casting Parts?

Testing Designs with 3D Printing

Brake for a 5 ton Cannon

Typists Correction Fluid

And Some More Bling on the Cannon

Happily Using Technology

More Small Cannon Parts

Armstrong RML Elevation Protractor

Next Project?

CNC Machining a Small Part

Fitting the Barrel Elevating Gears.

Barrel Elevation Gear

More Bronze Pour Problems and Cheap Spanners

Cannon Update

Tension Drilling.

Small Pliers

Ducks in a Row and Bevel Gears.

Ratchet Gear.

More Gearing Up, and more to come.

Rack Off

On the RACK

Gearing Up

Gears. Modularity Counts!

Blood Sacrifice

Casting Bubbles

And then got better….

It got worse

Learning from MISTAKES

BRONZE POUR- everything went wrong!

15% Phosphor Copper-2

Metal Casting Research

15 Phosphor-Copper Shot.

Spur Gears -1

Bronze Casting. Can You Bake the Investment Twice??

Japanese Knife

Bronze Tyrannosaurus Rex

Soft Jaws

First Bronze Castings

Trunnion Mounts -3

Making Sanding Belts

Covid 19 Problems

Trunnion Mounts -2

Trunnion Mounts -1

Using a Banggood tool to make spacers

Axles for a Cannon Carriage

Recovering from Friction Welding

Friction Welding

Carriage Assembly, and Gun Spiking.

Armstrong Cannon at Flagstaff Hill, Warrnambool. (yes, 2 r’s)

Casting Aluminium. It is just too light.

A Chuck in a Chuck

Armstrong Cannon Chassis Wheels

Model Armstrong Gun Cypher

How were Trunnions Joined to 1866 Barrels? Correction of a previous post.

Lasering the Model Armstrong Cannon

and some Carriage Wheels….

Model Armstrong Cannon. Assembling the bits. And a riveting improvement.

Firing a Model Cannon

My Daughter Has Caught the MetalCasting Bug

The (non) gripping power of rubber

Lost PLA Casting – 3rd pour

Brass Melt. Dangerous!

Video of Casting Small Complex Cannon Parts

Second Pour.

Tomorrow’s Pour. And a family member is interested!

A Closer Look at the results of yesterday’s Metal Pour

Metal Pour

Making a Tree

Riveting the Armstrong Cannon Chassis Model

Getting Ready for Casting

TURKISH BOMBARD – a-post-script. And metal casting setup ready.

Armstrong Cannon Wheel Assemblies -2

Armstrong Cannon Chassis Wheel Assemblies

Riveting for Real

Book Review. “Mortal Wounds”. Not for the faint hearted.

A Transom on a cannon. And a lost hearing aid.

Lost hearing aid.

Armstrong RML. A Little More Progress!

Armstrong RML Model cannon. Assembly -1

Small Steps. Armstrong Cannon.

Book Review. The Trafalgar Chronicle – 4

91 x 4 drilled holes. Yes, counting.

Armstrong RML Cannon Model. Making angle iron pieces.

Armstrong RML Model Cannon Parts

Armstrong RML Chassis Girders

Armstrong RML. The Chassis -1

Model Armstrong Cannon. Machining the trunnions-3.

Armstrong RML Cannon Trunnions – 2

Armstrong RML Cannon Trunnions 1.

Rifling the Model Armstrong RML

Laser Cutting High Speed Steel

Bronze Casting 3. Equipment.

Boxford TCL125 CNC Lathe, 3rd AXIS.

Bronze Casting -2

NBN. At Last!

Repairing Failed 3D Prints

Bronze Casting. 1.

3D Printing Question

Model Cannon Barrel. (T)rifling Thoughts.

Naval Gunnery. A Book Review.

Another Model Cannon Builder

Armstrong RML barrel

Armstrong RML. Roughing Out the Barrel

3D Printing a Cannon Barrel

3D Printing is FUN! (but still slow)

Armstrong RML

3D Printing is SLOW

?Next Project

So Many Mistakes! Am I Too Old for this hobby? Or is it the heat?

30 watt Laser in action.

Melbourne Society of Model and Experimental Engineers. Xmas meeting.

A modification to the Radius Master

Between the Classical Greeks and the Romans. The Hellenistic Kingdoms!

Bucket List. A Book Review leading to..

A Modification to the Acute Tool Sharpening System

RadiusMaster

Lathe Toolpost Milling attachment (CNC)

Tycho

Antarctic Sphinx

11:00 11-11 Remembrance Day

101 years ago, today.

Zhiyun Crane M2 improvement.

CNC Lathe Toolpost Mill

CONFESSION

Model Krupp Gun from Emden

6″ Vertical Boiler, Triple Expansion Steam Engine and Southworth Pump, all working together. Fairly well.

A VIDEO GIMBAL

34 degrees. Is it summer already?

Thinking about future exhibitions….

Royal Geelong Show 2019

Boiler Feed Pump Pumping

First Steam for Boiler Feed Pump

Workshop with security

A Workshop as Dark, Messy, and Dirty as Mine! Well, almost.

Mounting the Boiler Feed Pump

Boiler Feed Pump -Working

Workshop in the Deep North of Oz. North Queensland.

Next Tool Project…A CNC Laser Cutter

Southworth Steam Boiler Feed Pump Progress.

A European Workshop

Book Review. Battleship Bismarck. A Design and Operational History.

Another John’s Workshop.

Workshop Photos. Are all Modellers Obsessive -Compulsive Neat Freaks?

Bad Paint Job

The Boer War. A Book Review. Excellent!

Southworth Steam/Water Pump

Three more workshops. Why are they all so neat? Or am I just very messy?

TWO WORKSHOPS

Fit after 9 day influenza?

Houseguests

Southworth Steam Pump- first parts

Steam Powered Water Feed Pump

CNC Mill Upgrade -8

CNC Mill Upgrade – 7.

CNC Mill Upgrade – 6. Where to put the computer?

CNC Mill Upgrade -5

CNC Mill Upgrade -4

Upgrading the CNC mill -3. Moving a threaded hole in steel plate.

Installing the lathe gear

German Battleship Helgoland – book review.

CNC Mill Upgrade -2

Cutting the Gear

Not Antarctica Again! Groan…

Preparations for gear cutting

CNC rotary table and preparing a gear blank

Google Earth Antarctica Photos

CNC Mill Upgrade

Back to the Trevithick Dredger Engine Model – the lagging.

Model Engineers have Other Interesting Hobbies.

Modelling Jeeps and Tiger Tanks (books)

Large Scale Warship Models (a book review)

London Museum of Science Revisited

Final Day in UK. 2 more museums.

Portsmouth UK. 2 more great museums.

Fort Nelson. The Ottoman Bombard revisited.

BT. Before Trevithick.

Tin Mines

First Steam Locomotive.

Bolton Steam Museum

Museums Have Changed. “Rocket”.

Pontefract. Where playing around can cost your head.

National Rail Museum, York, UK.

The Most Powerful Steam Engine in the WORLD (?).

Harrison’s Clocks

Another 1000 ton Machine

Big Triple Expansion Steam Engines

Trevithick Dredger Engine at The London Science Museum

Broken Lathe Gear – Update.

OZ to UK

MASADA

A Fraternal Photo

Free History Books

A New Hobby for Metalworkers (a book review)

Lathe Woes

Back in the workshop, a Lathe Problem…

The Trafalgar Chronicle

How the world’s greatest navy was defeated by beginners. A book review.

Early Railways…A Guide for the Modeller (a book review)

Trevithick Engine by Lumix, and an Ottoman cannon.

Travel

Sir Ding Dong.

Video of the gas burner which works

At Last, a burner which does the job!

Travel Appeal

Another Good Read. “The Mongol Art of War”

More Gas Burner Experimenting

Experiment Failure

A Coal Grate. And Monster Emperors of Rome.

Trevithick Dredger Engine. Gas or Coal?

Not Another Book Review!

The Battleship Builders (another book review)

M1 ABRAMS TANK (a book review)

A Visit to The Boiler Inspector

Somebody is responding to my Antarctica Posts

Antarctica Again, Again

Next Project

Painting the Dredger Engine

Housekeeping

Trevithick Blower

Trevithick Dredger Engine. Almost There.

Oh Shit!

Beware of Greeks Bearing Gifts

Experiments With Propane and Paint

Trevithick Engine. Tweaking the gas burner. Winning?

Model Trevithick Dredger Engine on Steam. Fail. Well, maybe a bare pass.

Workshop Tidy

Drilling is not boring

A Long Drill Bit

Moon

Sight Glass on the Trevithick Boiler

Trevithick Dredger Engine. The Dredger

A Tour of the Model Dredger Engine

Making Springs and Other Stuff

Well, what a nice day!

Gas control on an historic model?

Historic Model Compromised?

Fitting the Boiler Feed Pump to the Trevithick Dredger Engine.

A Day In The Workshop.

Trevithick Dredger Engine Burner

Trevithick Gas Burner Problems

A Gas Burner for the Trevithick Dredger Engine

Trevithick Dredger Engine – Base -4

Trevithick Dredger Engine Base.- 3

Trevithick Dredger Engine Base -2

Trevithick Dredger Engine Base

Trevithick Boiler Feed Pump, and a base.

New Oxy-Propane Torch just watch!

Brass Lust

Timing the Trevithick Dredger engine-4

Timing the Trevithick dredger engine-3. How embarrassing….

Timing the Trevithick Dredger Engine_ 2 making the fittings

Timing the Trevithick Dredger Engine – 1. theory.

Trevithick Dredger Engine. The con rod bearing wedges.

I GIVE IN

Another axis for the Boxford 125TCL

Trevithick Dredger.. attaching the flywheel and driving gear to the mainshaft.

Making a Lead Ball for the safety valve

How Many One Off Parts Can You Make Per Day?

Boxing Day in Oz

Trevithick Dredger Engine.. the steam valve operator.

Trevithick Dredger Engine.. the firedoor fittings. Or silver soldering tiny pieces.

Trevithick Dredger Engine ….Con Rods

Trevithick Dredger Engine… hinges for the fire door.

Antartica Again!

More Trevithick, and Xmas

Trevithick Dredger Engine… No more aliens, just a gear

Trevithick Dredger Engine.. connecting the water pre-heater

Back to the Trevithick Dredger Engine. No aliens… promise.

Antarctica Again. Bear with me. This is so weird.

Why the SECRECY about ANTARCTICA?

Paranoia

WTF!

Read this response to Antarctic Weird

Bye Bye

Trevithick Dredger Engine- the stays

More Antarctic Weird – 2

Trevithick Dredger Engine Progress

Woodworking for the Steam Engine

Dredger Engine- Crankweb and Firebox Door

Scale Trevithick Dredger Engine- the Supports, and crank-webs.

Trevithick Dredger Engine Guide Bars

Trevithick Dredger Engine Guide Bars and Crosshead

Trevithick Dredger Engine- Valves

Home Invasion

Trevithick Dredger Engine….progress

Antarctic Weird.

Soldering the Trevithick Dedger Engine

Trevithick Dredger. A start on the Engine.

Hydrostatic Trevithick Boiler Test

Model Engines on Steam

Hydrostatic Boiler Testing

Why I Don’t Sweep Up Swarf.

Dredger Engine Bling

Trevithick Dredger Engine. Finishing the flat end plate.

Trevithick Dredger Engine- soldering the big boiler flange.

Trevithick dredger engine – second silver soldering session.

Trevithick Dredger Engine Boiler Bushes

Trevithick Dredger Engine Progress

Trevithick Dredger Engine – what was the original design? -2

New Spindle Motor for the Boxford 125TCL CNC lathe.

Trevithick Dredger Engine. What was the original design?

Drilling holes into the Trevithick Boiler

Trevithick Dredger Engine- First silver soldering session

Back to the Trevithick Dredger Engine

How does a 6″ vertical boiler enhance house decorating?

6″ Boiler Lagging -3, and back to the Dredger Engine.

Boiler Lagging -2

6″ Boiler. Lagging.

VR-18-18

New Skills in Retirement.

A steam driven water pump, and a whistle.

Almost ready for the boiler inspector.

Another pressure gauge.

6″ Vertical Boiler- the ID plate

6″ Boiler. First Steaming.

Boiler. The Pressure Gauge.

Boiler flame fixed, and firedoor progress

Boiler stand, gas fire, and firedoor latch/catch.

Just how strong is a silver soldered join?

A new skill- riveting stuff

Redesign Trevithic Model Dredger Engine

Trevithick Dedger Engine -Design Changes?

6″ Vertical Boiler. Finishing the firedoor

Hanging a door on a boiler.

Two steps forward one step back again!

6″ Vertical Boiler.Spearhead Superheater

Trevithick Dredger Engine-2 steps forward, 1 step back.

Trevithick Dredger Engine- Supports

How to make small bits of brass (or bronze) into big bits of brass (or bronze).

Trevithick Dredger Engine. Making and brazing the boiler cylinder tube.

Adjusting Pressure Gauges

Steam Driven Water Pump for Vertical Boiler

Trevithick Dredger Engine. Cutting through the domed end plate.

Trevithick Dredger Engine- bronze brazing and some milled parts.

Oxy-acetylene or Oxy-propane for silver soldering (and bronze brazing)?

6″ Vertical Boiler. Calibrating the pressure gauge

6″ Vertical boiler. 2nd Braze

A Nice Day!

Trevithick Dredger Engine- the flat end

Timing a Stuart Triple Expansion Steam Engine

6″ Vertical Boiler- First silver Brazing

Turning Concrete on a Metalworker’s Lathe

Gaskets with CNC, and progress on the Trevithick Dredger Engine.

6″ Vertical Boiler. Ideal soldering set-up block. Concrete!

6″ Vertical Boiler- Steam Outlet & Safety Valve Standard

6″ Vertical Boiler Chimney Flare

6″ Vertical Boiler- Chimney flange

6″ Vertical Boiler- Penetrations

6″ Vertical Boiler. The final flange on the smoke box.

6″ Vertical Boiler – drilling for bushes

Trevithic Dredger Engine – New End Plate

6″ Vertical Boiler- the Firehole

6″ Vertical Boiler Smoke Box Cover

6″ Vertical Boiler. CNC Drilling Firetube Holes

6″ Vertical Boiler, Using Clekos, and dropping the Traction Engine into a hole.

Vertical Boiler Firebox Wrapper

6″ Vertical Boiler

Trevithick Boiler End-2

Trevithick Boiler End

Home Made Ring Roller, and first attempts at bronze brazing.

Bolton 7

Another Use for Magnets

A New (to me) Tool

Trevithick Dredger Engine Flywheel

Buying Copper Pipe for Model Boilers

The OTHER NEXT PROJECT

Triple retrospective

BOILER FOR MODEL STEAM ENGINES

Small Tube Bender

Scale Traction Engine – installing a steam powered boiler injector.

How to time a Model Triple Expansion Steam Engine

First taste of steam for the MODEL TRIPLE EXPANSION ENGINE

Model Triple Expansion Steam Engine. First taste of steam tomorrow!

TRIPLE EXPANSION MODEL ENGINE- FIRST RUN (air)

Geelong Vintage Machinery and Classic Truck Show – day 2

Geelong Classic Truck and Vintage Machinery Show. Day 1.

Back to the Triple Expansion Steam Engine

More Wierd Stuff

A New Spindle Motor for Boxford 125TCL CNC lathe.

Triple Expansion Steam Engine Cylinder Cocks

Steam Trains in Colour

New Mechanical Oiler for Fowler Traction Engine

Recycling Leather

Traction Engine Oiler

Running in the Triple Expansion Engine

TRACTION ENGINE STUFF

Traction Engine Safety Valves

SNORING

Traction Engine. New Parts.

MAKING A PROTRACTOR for TRIPLE EXPANSION ENGINE VALVE TIMING

The Boiler Inspector.

MODEL ENGINES in the cage at the GEELONG SHOW

FOWLER R3 TRACTION ENGINE

2 Triple expansion steam engines.

Fowler R3 at The Geelong Show

Traction Engine Lamp Lenses

More Triple Photos

Triple Expansion Engine Update

TRACTION ENGINE (update)

Holes in Swiss Cheese.

Compound Traction Engine

Steam Trains

BAND SAW WELDER

INSTALLING LATHE LEAD SCREW COVERS

Horizontal Mill Engine (HME)

Traction Engine Disappointment

Wood Heater Paint

Boxford 125TCL CNC Upgrade

Heat in the workshop. Heaven!

Oz is hot. Right? Bloody Cold just now.

TRIPLE FINAL(?) ASSEMBLY

Model Ship’s Cannon

Koffiekop Modification

If at first you don’t succeed…

Another Diversion from The Triple

A Base for the triple, and some oil holes…

Making Hubcaps

Chariot Racing

Metalworking for a cabinet maker

Arduino Controlled Indexer-2

Triple Expansion Steam Engine Pipework.

Cutting a thread up to a shoulder

A Turntable for the Triple Expansion Engine.

Project in the Wings.

Edwards Pump for the Triple Expansion Steam Engine

NEW SPINDLE MOTOR for CNC LATHE?

Harold Hall Grinder Rest – modification; and triple expansion update.

The Robert the Bruce approach to turning problems.

New Steppers for an old CNC Lathe

Swap Meet Bargains

Assembling the Triple

A Full Size Weighshaft

Anyone for a swim?

The Steam Supply Valve

SS Valve Rods

Triple Underbelly

Reversing Gears and Handwheel

Broken Tap Removal

Triple Expansion Steam Engine -The water pump

MAKING SMALL SPLIT BEARINGS FOR THE TRIPLE EXPANSION STEAM ENGINE

Drag

Drag Links for Reversing Mechanism on Triple Expansion Steam Engine

The final 20% takes 80% of the time

Triple Expansion Steam Engine resumes

Turkish Bombard – the barrel mouth

Turkish Bombard. The Barrel Script

Turkish Bombard. The Arabic Script.

After the triple

Model Engineering Competition

More Scale Stuff

Model Ottoman Bombard – Painting

Ottoman Bombard Photo to Vector

TURKISH BOMBARD- HELP!

TURKISH BOMBARD – the real thing

Modelling A Turkish Bombard- The Pins

Modelling a Turkish Bombard -4 Decoration

Bombard Model-3 turning the barrel

Bombard Model -2. Big Thread

Bombard Model. Turning the Breech

Turkish Bombard 1:10 scale

CNC Lathe Conversion- final

A Matter of Scale

CNC Lathe Conversion – 17

Steam Engine Oilers

OK, so guess the purpose

MORE ANCIENT GREEK TECHNOLOGY, THE ANTIKYTHERA MECHANISM

ANCIENT GREEK MACHINING

CNC Lathe conversion -16

CNC lathe conversion -15

CNC lathe conversion -14

CNC Lathe conversion -13

CNC Lathe conversion -12

CNC Lathe conversion -11. Ball screw machining.

CNC Lathe conversion -10 Trig is useful.

CNC Lathe conversion – 9

NOT MUCH GOING ON TODAY

Workshop Tidy

CNC Lathe Conversion – 8

CNC Lathe conversion-7

CNC lathe conversion-6. EBay problem

CNC Lathe conversion -5

CNC Lathe conversion -4

Ball Screws -2

THROAT CUTTER WALL SMASHER

COMPRESSED AIR ON THE CNC MILL

Lathe conversion to CNC -3 Ball Screws

Lathe Conversion to CNC -2 and Wall Smashers

Lathe conversion to CNC

CARRONADE VS LONG GUN

POLISHING TINY BRASS PARTS

CANNON BALLS FLOAT IN THIS LIQUID

CARRONADE 1

MACRAME FOR MACHINISTS

OLDEST STEAM ENGINE- Model

Seismic Wave Generator

THE POWER OF WATER

Video of Making the Model Naval Cannon

German Engineering

Shear Wave Seismic Source

1779 Naval Cannon Scale Model

Cannon, final parts.

Cannon trunnion shoulders, flash pan and trunnion brackets.

Cannon Trunnions

Turning a cannon barrel

New Gates

Making a Cannon Barrel is boring

1779 Scale Model Naval Cannon

More Australian Wildlife

A short Dan Gelbart video for machine lovers.

1779 Cannon Bling

More Naval Cannon

24 Pounder Naval Cannon

DESERT IRONWOOD

Homemade lathe with ONE MICRON accuracy.

Moving a biggish lathe

TAPPING GUIDE

Boxford CNC lathe (5)

BACK TO THE TRIPLE

2015 in review

Milling a taper in thin steel

December Heat

Centering the Mill using Video Camera

A Matter of Scale

COLCHESTER LATHE BADGE REPAIR

SOFT JAWS FOR LATHE

BOXFORD CNC LATHE (4)

BOXFORD CNC LATHE (3)

BOXFORD CNC LATHE (2)

BOXFORD CNC LATHE

A Collet Chuck for the Colchester Lathe

ACUTE TOOL SHARPENING at GEELONG MODEL ENGINEERS’ EXHIBITION

Der Tiger at Geelong Model Engineers

Broken Cold Saw Blades are a good source of Tool Steel!

Copper and Brass Repair

Prize Winning Hit and Miss Engine

Steam Powered BBQ Rotisserie.

Steam Logging Winch at The Royal Geelong Show

The Royal Geelong Show- Vintage Machinery Shed

Beam Engine, First Run on Live Steam

Cheap Engine Turning

Making Small Gaskets

Model Marine Boiler and another Koffiekop.

Stirling Engine Failure. Now Successful!!

Flywheel and Sugru

KoffieKop Engine Working!

Koffiekop Engine

Triple Rest

Problem with Balls (Incarcerated ball bearing)

Making the Lathe Spider

Lathe Spider

Stephenson’s Link Rods

Stephenson’s Link Yokes

SUGRU

Stephenson’s Link (2)

Making a Stephenson’s Link for a triple expansion steam engine

AMAZING FIND IN KAZAKHSTAN

On being a grandparent

STUSSHED at GSMEE

Beam Pump

The Future of Motoring

Digital Read Out (DRO) for Colchester lathe, and problems with Apple Mac

New (to me) Toolpost for the Colchester

Triple Eccentrics, 4th attempt success.

MODEL ENGINEERING EXHIBITION at BENDIGO, VICTORIA, AUSTRALIA

More Drilling and Reaming of Deep Dark Places

ELECTRONIC JOY

TRIPLE SH*T

Colchester Master 2500.

PROTECT YOUR SAUSAGE

More Other People’s Machines

BUYING A LATHE

Triple Expansion Steam Engine Update, and some toy making

No Mobile Phone, No Problem???

NO PICTURES, JUST WORDS.

JOINING DARK PLACES

MAKING DARK PLACES

INJECTION of INSPIRATION

BOILER PAINT

Triple Condenser Covers

Other People’s Triples

SILVER SOLDERING SUCCESS.

THE CONDENSER- not so easy afterall.

DARK PLACES

ACHLUOPHOBIA or ATYCHIPHOBIA?

Cylinder valves for triple, and a neat method for cutting thin grooves.

Piston rods for triple, and some engraving.

Pistons for triple expansion steam engine.

24000 RPM spindle for CNC Mill 2

24000 RPM spindle for CNC Mill

Make Your Own LONG SERIES TAP

TRIPLE UPDATE

TIGHT MAIN BEARINGS NEED GUMPTION

Con rods for triple -3 finished!

CON RODS for TRIPLE -2

CON RODS FOR TRIPLE

MAIN BEARINGS BORED on TRIPLE

CRANKSHAFT on base of triple.

MAIN BEARINGS FOR TRIPLE

Other People’s Triples

CRANKSHAFT FINISHED!

John and John having fun again, on Puffing Billy

CRANKSHAFT, almost finished

TRIPLE EXPANSION STEAM ENGINE ANIMATION

FISHING IN BOTSWANA

More Crankshaft. Roughed on mill, finished on lathe.

CRANKSHAFT- using the mill instead of lathe

How a surgeon starts awkward, tiny nuts.

CRANKSHAFT – early steps

STEAM CHEST PROGRESS

MAKING STEAM ENGINES, CIRCA 1905

WHEEL BALANCER- another home made tool

MAKING BAND SAW BLADES

Bolton 12 Beam Engine Under Steam

STEAM CHESTS for TRIPLE

VULTURES

EXPERIMENTING WITH CNC MILL TAPPING

BOLTING THE TRIPLE CYLINDER HEADS, and another jig.

TRIPLE CYLINDER HEAD CAPS

HOW TO MAKE A FULL SIZE STEAM ENGINE

TRIPLE BORING CYLINDERS

TNC lathe restoration completed.

MORE BOTSWANA & ZIMBABWE

Victoria Falls, Zimbabwe

On the ninth day of Christmas, my true love said to me…

Look at what the bloody crocs have done to my skin!

We’re married, OK?

John and the jawbone of an elephant.

The Most Fearless, Savage Animal of all

Thick Skulls

In Africa, you need to look both ways…

Dracula, Eat Your Heart Out.

You are in my way!!

WHERE’S WALLY

TRIPLE CYLINDER BLOCKS JOINED

TNC Lathe restoration progress

Cylinder Bases. Lathe or milling machine?

Buying Tools and other stuff at a swap meet.

TRIPLE PROBLEM

Triple progress

SHORT VIDEO OF CNC CENTRE DRILLING

108 Accurate holes. CNC again.

Machining the columns on the Titanic Engine Model

A JIG for Machining the columns of the triple expansion marine engine

MAKING GATES

TNC Lathe renovation 3

Boxford CNC lathe repair

TNC Lathe renovation 2

TCL lathe renovation 1

LATHE OBSESSION

CNC Mill 11

An Improved Lathe Stand.

More Inca stonework. Awesome.

CNC lathe tool holders.

Peru

LATHE RESTORATION

MILLING THE COLUMNS for THE BOLTON 9 MARINE ENGINE

GSMEE EXHIBITION 2

CNC Mill 10

GEELONG SOCIETY OF MODEL AND EXPERIMENTAL ENGINEERS ANNUAL EXHIBITION 1

Beam Engine Driving Wheel 2

Beam Engine Driving Wheel from a Big Lump of Aluminium

TAPPING HOLES. BOLTON 9. (Triple Expansion Marine Steam Engine)

TRIPLE EXPANSION MARINE STEAM ENGINE 3

Model Triple Expansion Marine Engine.

TRIPLE EXPANSION MARINE ENGINE 2

TRIPLE EXPANSION STEAM ENGINE 1

NEXT LAKE GOLDSMITH STEAM RALLY Nov 1-2

CASTINGS ARRIVE AT LAST!!

ROYAL GEELONG SHOW

RIDDERS “BOBBER” HEAT ENGINE

Beam Engine Ready for Painting

CNC MILL 9

CNC MILL 8

CNC MILL 7

CNC MILL 6

CNC MILL 5 with some more pics

CNC Mill 4 (with some pics)

CNC MILL 3

CNC Mill 2

CNC Mill

New Toy

DIVERSION

Burrell Traction Engine

Burrell Traction Engine

Collet chuck for CNC lathe

More POWER OF HYDRAULICS

Morning Mist at The Farm

BLUE TONGUE LIZARD HOME DISRUPTED!

USING TRACTOR HYDRAULICS TO DO THE HEAVY LIFTING

I Love hydraulic POWER

A MUSIC LESSON FOR THE METALWORKER’S APPRENTICE

NICKEL PLATING CAST IRON 2. AFTER MACHINING, BEFORE PLATING

NICKEL PLATING CAST IRON 1. THE CASTING

NICKEL PLATING CAST IRON 3. AFTER NICKEL PLATING

USING EBAY TO SELL FARM EQUIPMENT

BIGGEST WORKING STEAM SHOVEL IN THE WORLD

WILL THIS BLOG CONTINUE??

LAKE GOLDSMITH STEAM RALLY

MORE LAKE GOLDSMITH MACHINES

INCREDIBLE LAKE GOLDSMITH PARADE OF STEAM ENGINES

STEAM POWERED SAWMILL, looks bloody dangerous to me!

BIGGEST WORKING STEAM SHOVEL IN THE WORLD

Redgum steel press

INTO REDGUM

TOOLREST FOR GRINDER -2

TOOLREST FOR GRINDER

INTERREGNUM

THE NICKEL PLATED WORKSHOP -2

THE NICKEL PLATED WORKSHOP

Electroplating

Boiler for steam engine

Beam Engine steam pipes made and installed 3 March 2014

Making a copper boiler

A Small Full Size Beam Engine

John Made Ring Roller

Bolton 7 Gunmetal castings

Bolton 7 Iron castings

John in Istanbul

MUSIC

Bolton 9 Triple Expansion Steam Engine

Roller for applying herbicide

Backhoe Grab

Beam Engine Steam Pipes, variation number 3

This is how I spend my Saturdays

Bolton 7 Boiler changes

BOLTON 7 STATIONARY STEAM ENGINE CHANGES

MAKING OIL CUPS FOR THE BEAM ENGINE

Making the Bolton Beam Engine

Beam engine operating

SUCCESS! BEAM ENGINE RUNS (BRIEFLY) ON COMPRESSED AIR

BEAM ENGINE, FIRST RUN, ON COMPRESSED AIR.

BEAM ENGINE, FIRST RUN

FRUSTRATION

Steam Chest Uncovered

Beam Engine steam pipes made and installed 3 March 2014

Steam Cock and valve. Making the handle.

Bolton 7 working with live steam

Machining the flywheel

Almost Finished Beam Engine

Beam Engine castings

Beam Engine Governor Gears

Beam Engine Parallel Motion

Beam Engine

Bolton No 7 and boiler

Backhoe grabber

Solid Copper Riveting. What I have learned.

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.

  1. Copper rivets are annealed when purchased, but as soon as you start hammering them, they harden.
  2. 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.
  3. The compressor pressure is critical. The air setting on the hammer is critical. Experiment on waste material first!
  4. Hold the fixed snap in a strong vise.
  5. The snaps need to be accurately made for the rivet size. Try them on waste material before using them on the job.
  6. 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.
  7. The surface of the snaps should be smooth, with rounded edges. A polished finish is best.
  8. 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.
  9. Some rivets will not insert well. Just remove them, and try again.
  10. 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.
  11. 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.
  12. 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.

Final Lasering on Armstrong RML model cannon

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!)

3D Printer Plate Adhesion Problems

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.

Armstrong RML model No 2 Finished!

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.

Bronze Casting a model Turkish Bombard-1

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.

A Visit to an Old Friend

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.

Cheap Epoxy Metal Repair/ Filler, and Initial Painting Model Cannon

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.

Silo Art Trail

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!

Salt Pans, Sand Hills, Blue Skies.

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.

….next chapter…. silo art.

Bush Camping At Hattah-Kulkyne

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.

…..to be continued…..

2 Model Cannons- Materials and Processes List

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.

Australian Ship Sunk by US Navy

OK. Click bait title. But probably correct.

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.

Model Cannon. Last (?) Teardown.

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.

A Dilemma. Wheels or handles for running back the Armstrong 80pr RML Cannon.

And why I made a significant design change.

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.

Walking Dead Chess Men

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 cycles
and 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.

Casting Brass Chess Pieces- 2

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!

Pre-teardown Model RML Cannon

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…..

  1. I had made some design changes. Always risky. Always time consuming.
  2. I could not find some notes and photographs which I was sure I had carefully filed away.
  3. 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.
  4. SWMBO had other ideas about the best method of using my time, and making model cannons did not enter her equations.
  5. 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.)

SWMBO Break

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.

Chess Men. Next step, make a tree

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.

Casting in a day or 2. Watch this space.

Painting a Brass Label

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 right
Then 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.

Chess. 3d printing complete.

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.

Now, THIS is a SHED!

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 a