Before I am hung, drawn and quartered, for operating a lathe without guards, here is the proof that I have been sensible.
Before I am hung, drawn and quartered, for operating a lathe without guards, here is the proof that I have been sensible.
First Test Run
After some test runs without tool or material, I performed some measurements.
500mm movements along the Z axis were reproduced multiple times with a deviation of 0.00mm! (the Z axis has a ground ball screw)
100mm movements along the X axis deviated 0.02mm. (the X axis has a rolled ball screw).
I was delighted to note that the lathe is extremely quiet and smooth. The only noise is some belt slap from the very old belts, and from the stepper motors.
The video below was taken from my iphone, while I was operating the lathe controls, so please excuse the erratic movements.
The steel is 27mm diameter. 750rpm, 50mm/min feeds.
And the guards will be made next step, without fail.
The G code was generated using Mach3 for these very simple shapes. For more complex items I use Ezilathe.
The lathe is 600mm between centres. 38mm spindle bore. Swing about 300mm.
Knowing that I have an interest in CNC machining, Tom, from the Vintage Machinery Club in Geelong asked me to make a pair of oilers for a very old Wedlake and Dendy steam engine. The engine is a large (to me anyway) stationary engine, which is run on steam several times each year. The oilers for the cross slides were missing.
We searched the Internet for pictures of W&D steam engines, but could find no pictures or diagrams of the oilers. So Tom sketched a design, and I drew a CAD diagram. The dimensions were finally determined by the materials which I had available… some 1.5″ brass rod and some 1.5″ copper tube.
This is the almost finished product.
The oilers work by wicking the oil from the reservoir into a tube which drains through the base onto the engine slide. When the wick tubes are fitted the oilers can be fitted to the engine.
My lathe is a Boxford TCL125, using Mach3. The G code is generated using Ezilathe.
Below is a link to an oil cup from “USS Monitor”, of American civil war fame. One of the first ironclads, powered only by steam.
(ps. The lathe which I was converting to CNC was the subject of previous posts and is now working, but needs some guards fitted and a bit of fine tuning.)
This mechanism was discovered in 1901, in a Roman era shipwreck, off the Greek island of Antikythera, which is a bit north of Crete.
It has been dated to between 100BCE and 205BCE, with the older date considered the best estimate. ie, about 2200 years old. Experts believe that its makers were Greek.
It is currently housed in the Greek National Archeological Museum in Athens.
Look it up on Wikipedia..
According to the Wikipedia entry the gear teeth are too irregular to have been machine cut,
but watch the computer reconstruction. Could you make this machine without a lathe and gear cutters?
How much more technology did the ancients have that has not survived the ravages of time? A lathe for example.
I recently had a light globe switched on in my brain.
I was holidaying in Athens (the one in Greece), and was gobsmacked by the huge, fabulous collection of statues, mosaics, ceramics, gold jewellery and masks, bronze and iron weapons in the National Archeological Museum. I took many photos, and might post some in later blogs.
Three items sent shivers down my spine.
There was a display with many surgical instruments. These have been found at various archeological digs in Greece, and while not precisely dated (at least not labelled) they are mostly from 500-200 BCE.
My eye was immediately drawn to an instrument which looked very familiar. I was a gynaecologist in my previous life, and this could have come from my instruments. (except that the dark bronze surface might not have been acceptable to patients).
The instrument is labelled a vaginal dilator, but I am quite certain that it is a vaginal speculum. A speculum is used to inspect the vaginal walls and uterine cervix. (That might be too much information my metal working/ engine making/ machinery minded readers. If so, too bad.)
It is said to be made of bronze. The Ancient Greeks were highly skilled at metal casting, as evidenced by the many complex and beautiful bronze statues and weapons and implements on display.
It interested me for several reasons. Bear in mind that not many archeology museum visitors are gynaecologists who know about making threads in metal.
It looks quite functional, and if cleaned up, given a shiny surface and sterilized it could be used today.
The threaded section is very regular and smooth. I would loved to have taken some measurements of the thread with a micrometer, but had to be content with a prolonged inspection through the glass case. The thread appears to me to be so regular, that it could not have been hand filed. It must have been machine made. I have seen hand made threads on medieval machines, and they are crude compared with this one.
Either this is not an ancient Greek instrument but a more modern instrument accidentally included in the display (pretty unlikely, considering the professionalism of the people involved). (ps. If you Google Pompeii speculum, you will see that similar instruments have been unearthed at Pompeii… buried since 79ce.)
Or….. the ancient Greeks had screw cutting lathes.
Ridiculous you say?
Wait until my next post about the Antikythera machine. If if you just cannot wait, look it up. It is mind blowing.
Compressed air is very, very useful on the milling machine. The tool changer uses air for fast tightening and release. And I often use air to clear the field of swarf, and shavings (yes, I use my mill for wood too).
Recently, at the suggestion of Stuart L of stusshed.com fame, I installed 2 semipermanent nozzles on the mill, with adjustable direction and pressure adjustments. It has been a quantum leap improvement.
The pic shows the jets aimed during CNC end milling of wood. The wood shavings are blown away which makes it easier to see how the milling is progressing; blows them away from me which is safer and cleaner; and stops the chips being machined into the work, which leads to a cleaner cut. It also improves any video or photo of the progress. It must also cool the cutter, although not as effectively as a liquid coolant. I have not tried using the misting attachment, which would improve the cooling, but at the cost of dampening the area and the work.
I particularly like the improvement experienced when machining brass or steel. The swarf is removed from the advancing cutter, preventing it being re-machined and squashed into the workpiece. I am noticing better surface finishes. I also adjust the air direction to keep the swarf away from me; particularly valuable when brass needles otherwise would be flying at me.
When cutting pockets, the air keeps the pocket free of swarf, and when using tiny endmills at high speeds I am experiencing fewer tool breakages.
This gadget was inexpensive ($AUD12) from China. It does not work the compressor too hard when the volume is turned back as far as possible, but still adequate. Although there are 2 jets, I find that only one at a time is adequate.
As an afterthought. I rarely use coolant on my lathes, but an air stream on the cutter and workpiece would probably have similar advantages to those listed above. I particularly wonder if it would assist during deep parting… always a tense procedure. I suspect that the cutter becomes hotter and expands more than the workpiece parting slot if there is no coolant. I will mention the result of air cooling and chip clearing on the lathe in a later blog.
To continue the posts about making the seismic wave generator. See the previous post about water jet cutting the steel plates.
From what I am told, the generator is positioned, pinned to the ground, and hit on the ends with a sledge hammer. Instruments pick up and measure the seismic waves in order to analyse what is beneath.
Sound is not required. In fact sound is annoying and a disadvantage.
The operator stands on the generator while swinging the hammer.
So here is the finished item, ready to be delivered. It weighs 20kg.
It will be interesting to hear how it performs.
Click on the arrow in the screen link below to connect to the YouTube video of the making of the 1779 model cannon. Probably of interest only to machine aficionados, but it does feature some very pleasant music composed and played by Lis Viggers.
The labels appear too briefly, so use the pause button to read them.
The segment on boring the barrel is really boring. (really)
And a few editing errors appeared. I typed cascobels when it should have read astragals. Not prepared to delete, re-edit and re-upload given my very slow Internet connection.
And this is a link to another YouTube video with an excellent description of how these type of cannons were made originally. Definitely worth watching.
The 1779 model naval cannon is complete, finished!
Photos of finished project in next blog.
The last task was to make the bolts, hinge and keys which hold the barrel to the carriage.
These small items took 2 days to make, demonstrating that the size of parts has no relation to the the time taken to make, except in an inverse relationship. ie. the smaller the part, the harder and longer it takes to, make it.
The bolts which hold the barrel trunnion to the carriage have small rectangular holes which hold a key. The holes are 2.4mm wide and 3.6mm high. That is smaller than my smallest file. My smallest endmill is 2.38mm diameter, so that determined the size of the rectangular holes.
I drilled the holes with the endmill, then elongated the round hole to a rectangle by filing.
The problem was that my smallest file was a square file 3x3mm.
Solution! I ground the teeth off two surfaces of the file, leaving 2 faces 2.4mm apart, and 2 cutting faces 3mm apart. (using a surface grinder).
Then I had to make the keys. These are truly minute!
So I cheated. I CNC’d the shape on the end of a piece of brass rod, then parted off the keys in the lathe.
Another couple of long and very enjoyable workshop days, making various bits for the 1779 24 pounder model naval cannon.
As you can see, this cannon project is almost completed. A few more hours to make some bolts and fittings. I am considering adding some ropes and pulley blocks.
I am unsure whether the trunnions are the semi circular holes in the carriage, or the cylindrical bits of the metal barrel which support the barrel. I am going to assume that the trunnions are the part of the barrel. (I checked. The trunnions are the cylindrical parts of the barrel which support the barrel.)
So, today I made some trunnions and silver soldered them to the barrel. In the full size original version they would have been part of the barrel casting.
But before that, I polished the barrel with a Scotchbrite type pad, impregnated with some polishing compound. And it made the barrel sparkle!
Then I attached the knob at the breech end, M4 threaded rod attachment.
Today the exterior surface of the model 1779 naval cannon barrel was turned.
The piece of brass material weighed 5.1kg, was 300mm long and 50.8mm diameter.
I had used Loctite to glue a spigott in the bore, to provide a center and a driving diameter which the small CNC lathe would accept.
Although the lathe was nominally 300m between centres, the toolpost would move only about 200mm. So the turning had to be accomplished by turning the cannon mouth end first, and then reversing the workpiece to turn the breech end.
The CNC lathe, owned by Bob Julian, is about 30 years old, and it came out of a school. In the course of this job, it seemed to progressively free up, making us suspect that this is possibly the first time it has ever been seriously used.
The lathe electronics had been replaced by Stuart Tankard to use Mach3. The G codes were generated by Stuart’s program “Ezilathe”, which is available as a free download on “CNC Zone”. It is an excellent CNC lathe program, and I thoroughly recommend it.
I will eventually post some videos of the turning progress, but my Oz internet connection is so slow, that for the moment I will post photos only.
I started by turning a piece of rubbishy pine as a test.
The starting weight was 5.1kg. The end weight, including the spigott was 2.9kg. So at least 2kg of brass swarf, most of which I swept up and saved for possible future use.
Next to machine the trunions and some silver soldering.
I decided to buy another metal lathe. For a few years I have been using a Chinese heavy duty machine, a GBC, which was 1000mm between centres and a swing of 400mm. It is a heavy duty machine, weighs 2 tonnes, and does its job. For turning large objects, up to 400mm diameter, and taking off large amounts of swarf quickly, it is excellent. But I must admit to a lack of pride of ownership of this machine. Particularly after being exposed to British workmanship in my small Boxford.
So I had a look around, and settled on a Colchester Master 2500. It is less than half the weight, and physically smaller, although the work dimensions are similar to the GBC. I persuaded SWMBO that if I sold the GBC, the small Taiwanese lathe, and the 2 Smart & Brown lathes which I had restored (see earlier posts), I would just about break even, have more space in my workshop, and there would be less stuff for her to get rid of if I happen to cark it at some inconvenient time. Also, the Colchester should not be difficult to resell. It has an excellent, almost legendary, reputation, and as I discovered, commands high second hand prices.
This process was actually jogged by seeing a Colchester on ebay which was of interest. It was cheapish, no bids, and the photos were awful quality. So I rang the owner. He had bought the lathe 3 years earlier, but had never used it because he did not yet have 3 phase power. The owner before him had used it to make hinges or something similar, as a backyard industry, and before that it had been in a school. In my experience, school lathes tend to show little wear, but often show evidence of crashes. The owner sent me photos of the bed, which did show dings from crashes, but nothing terrible.
So, full of optimism, I hooked up the tandem trailer to the old Landcruiser and drove the 250km to the other side of the state. To cut the story short, the lathe looked OK, but when I removed the gearbox cover, first the oil was old, black, and thick, one gear had a tooth missing, and another was severely worn. I took the owner at his word that he did not know about this condition (possibly correct), thanked him for his time and went home. It had been a pleasant drive.
(note added 23 June 2015. The seller is still advertising his lathe, same price, no mention of the broken and worn gears. I am inclined to think less charitably about someone who would let a buyer drive 500km and not be honest about the item being sold.)
Next stop was a machinery second hand dealer. They had 7 Colchesters, from a University workroom closure. They were much more expensive, had been nicely cleaned up, had all of the chucks, steadies, tool holders, manuals etc. I did seriously consider one of these, which had a few dings on the bed, but otherwise looked good. I decided to sleep on the decision.
Next day, I visited two more ebay sellers with Colchesters. I have racked up about 800km looking at possibilities. The first was from a factory close down. It was dirty, old, and had only a 3 jaw chuck. Despite its industrial past, it showed little visible evidence of wear. But the reversing handle would not stay engaged. No big deal according the owner, just a spring to be replaced. Hmm….. The price was OK, but not negotiable. I would think about it. Quite tempted with that one.
Then a tollway trip to the other side of Melbourne. My last option. In case you were wondering, this plethora of Colchester lathes is very unusual. I have been looking for this model for about 2 years, but have never seen more than one Colchester Master 2500 advertised within striking distance at one time. So having 7 or 8 to examine has been fantastic and unusual. Maybe everyone is wanting CNC these days.
The last one was an ex Department of Defence machine. It was midway in the price range, but negotiable. I could not fault it. It was tight, no dings at all, had clean oil in the gearbox, gears all intact, and had a full range of chucks, faceplate, tool holders, steadies etc. No manual. Needs a repaint. Probably 25-30 years old. (note added 23/6.. more like 45 years old!) Being DOD, it would have been fastidiously maintained. So what was the catch? I could not find one. I negotiated a lower price, and shook hands.
Next to pick it up. Then to sell my existing lathes.
Watch this space.
Apart from contending with fauna in my workshop (a tiger snake) , I did actually make some progress today.
Today I assembled the base, columns and Jig, intending to mill a flat top to the whole assembly.
To my surprise and dismay, it was apparent that one of the columns was one mm out of position. Dont know how that happened. A typo in the CAD drawing or CNC program? It could not be a zeroing issue, because all 3 columns on that side would be out of position.
What to do?
I decided to turn the 2.5mm holes in the column base into slots 3.5mm long. The bolting position on the jig was exactly correct, so I used that to zero the position, found a 2.5mm end mill, and gingerly milled the slot. holding the column upside down in the milling vice.
Fortunately, that seems to have worked. The columns are now all correctly located. The tops of the columns are the crucial plane and position, and they seem good. I doubt that the slots will be an issue in the finished engine. They are invisible under the column feet. If necessary, I will make a couple of locating pins and drill them in position right through the base from underneath. I doubt that will be required.
After that, I did take a milling skim off the column tops, to create a dead flat plane, to which to bolt the cylinder bases, when I have made them.
Not tomorrow though. I am off to Ballarat Victoria to a swap meet on the aerodrome. In previous years there have been approximately a thousand stalls. Some are shed clean outs, some commercial vendors and dealers, and lots of ancient cars and machinery and parts. The best stalls are the ones selling used tools. I seem to come home after each meet with a heavy pack full of tools and materials, and a lighter wallet. But it is always interesting and fun.
Today I made the BA7 studs for the columns on the triple expansion steam engine. I decided to use 25mm bolts, then trim them to length after they were installed into the threaded holes. Why not use threaded rod or make my own studs on the CNC lathe I hear you asking? Well, I could have made my own studs. In fact I did make 2 studs, quite succesfully. But it was time consuming. Cutting up threaded rod would have worked, but it turned out to be less expensive to buy over length bolts which are threaded right down to the heads, and trim them to length, than to buy threaded rod. Plus, the trimmed bolts are now quite useable 12mm bolts. Also, it was easy to use the bolt hex head to screw them into the threaded holes.
I did manage to break off one stud and spent a half hour or so digging the stub out and renewing the stud. But no permanent damage.
This is the project which has kept me away from the engines and lathes lately.
SWMBO suggested that maybe I could put all of those expensive metalworking machines to some practical use by making some gates for her current project, which is a house renovation.
Recently retired, and therefore with no reasonable excuse for declining, I had to say “but of course”. The option was to get a professional to make and hang the gates, but I could not think quickly enough of an excuse that would be persuasive. Wanting to get back to the triple expansion engine and the TNC lathe just would not cut it. Cutting and welding steel in our Australian summer is usually a big No No, due to the risk of fire. But we are having a relatively cool summer so far, after a very dry spring, so there is very little fuel around my sheds making the fire risk not too huge.
The fence has 40mm galvanised iron posts, and the fencing material itself is welded galvanised mesh. It is only 900mm high, typical for the houses in the area. The original gates were rubbish, so I removed and scrapped them. The previous owner had removed a section of fence to allow access to the back yard, so 2 sets of double gates were required.
My architect wife decided that the original style of fence and gates should be retained. I think that the style is termed “industrial boring ugly”, and has no function except to mark the boundary, and maybe to keep a very small dog, and/or child, off the street. But mine is not to reason why…….
So I measured the openings, roughly guessed the fall over the openings at approx 50mm, and sketched an elevation. Not complicated. I allowed 25mm for the hinges and 25mm for the centre gap. Bought the galvanised steel pipe (4 lengths of 6.4m x 33mm) and ordered the mesh to match the existing fence mesh. The steel merchant obligingly cut the steel lengths in half so I could carry them on my roof racks. Also some cold gal paint, and pipe caps. Total cost … $A370. The mesh panels came only in 2.5 meter lengths so I could get only one gate from each length, with a meter of waste from each gate. But I guess that the waste will be used somewhere. It would make reasonable reinforcing mesh for concrete. Or maybe a personal entry gate.
Measuring, planning, and buying steel had comfortably occupied a couple of days (that’s when I managed to get some paint on the little lathe), but SWMBO was getting impatient for some real action, so I cut up the steel.
The verticals were easy, All 800mm. Cut one, and used it as a standard for the other 7 verticals. The biggest problem was manoevering the lengths of pipe in my now overcrowded workshop. The drop bandsaw quickly munched through the medium weight pipe.
The horizontals were a bit more complicated. There are 3 possible methods of joining pipe where the horizontal butts up to the vertical.
The first simply makes straight cuts and the horizontal ends are flattened to permit a weld to the vertical. This is the method most often used on the farm, but it is a bit “agricultural”.
The horizontals and verticals could be cut at 45 degrees and mitre welded together. Not quite the look desired.
So I cut the horizontals with a hole saw which is the same diameter as the pipe, resulting in a very neat fit to the vertical. I had not used this method before, but it looked feasible. The pipe was held in a milling vice and the bi-metal hole saw was attached to the drill press. Using a slow speed (200 rpm), cutting fluid, and a slow feed rate, all went well.
The verticals and bottom rail were welded together. I used a MIG welder, and chose to burn off the zinc galvanizing during the welding rather than grind it off. That is a bit quicker and messier than grinding. I cramped the pipes to be welded to a thick bit of plywood, to minimise distortion and keep the 90 degree angles, and also to keep the frame as flat as possible. A steel welding bench would be better. And yes I did need to put out a few small plywood fires.
The mesh was cut to size using bolt cutters. The top rail was welded into place, after feeding it through the mesh (see photo). The mesh was then welded to the frame.
The welds were then all wire brushed clean and sprayed with cold gal paint. (a zinc rich paint which looks similar to galvanising).
I forgot to mention that the pipe hinges were put onto their respective verticals before completing the welding of the frames. Actually I forgot the hinges on the first frame, so I had to cut a weld to place the hinges, then reweld. Stupid, but I made that mistake only once.
So, back to the site to weld the hinges to the posts. But by now it was 34 degrees (centigrade), and the sun was fierce. I could have proceeded, but my glasses were steaming up, I was tired, hot, and bothered, so I dumped the gates and decided to wait for cooler weather.
Today (2 days later) was a bit cooler, so Tony (my blacksmith friend) and I welded the gates into place. Vertical up welds are a bit beyond my expertise, so I was happy to enlist an expert. (Thanks Tony).
So, almost finished, rather boring, thanks for bearing with me. John. More on the triple expansion next blog, promise.
I CNC’d a new handle to replace the broken one on the little lathe, but the new one made the old ones look a bit shabby, so they will all be renewed. The new, deeply waisted handles are very nice to use.
The headstock shaft was 3/8″ and was a bit undersized due to wear, and I intend to use a collet chuck with a 10mm shaft, so I decided to increase the shaft size from 3/8 (9.525mm) to 10mm.
The headstock bearing housing is split, to permit some adjustment with wear. I used a reamer with spiral teeth to avoid the teeth snagging the split. And all seemed to go very well using the setup in the photo below.
…Until I finished and raised the milling machine head out of the work.
Due to my lack of familiarity with the CNC mill controls I activated the X axis rather than the Z axis. The side movement broke the reamer and partially gouged the newly reamed lowermost housing. Bugger. Bugger.
What to do. Throw the whole project into the scrap bin? (following a few others). Change the shaft to the next size (12mm) and enlarge the housing holes to 12mm? That would thin and weaken the housing. And would be tricky machining. Also, due to the damage in a lateral direction caused by the mishap, I was not sure that drilling and reaming, or boring and reaming, would not follow the same lateral path.
At least the uppermost housing was undamaged, so whatever tool was used would be held concentrically, as long as the cutting edge extended the distance between the 2 housings.
So I very slowly drilled 11.5mm (the 11.5mm drill did span the distance between the 2 housings) and re-reamed to 12mm, again as per the above photo. Despite my misgivings, this time it all went well. The 12mm shaft is rather tight, and the housings will need some lapping. The housings appear to have enough thickness remaining, but time will tell in that regard. The lateral direction of the shaft is not perfect, but in such a small lathe that is not a big consideration.
As a consolation, and to retore some self esteem after this muck up, I made a new chuck key.
The chuck is held onto the shaft with a 3/8″ x 24tpi thread. That thread was cut on the CNC lathe, and is probably fairly accurate. The oil cups are spare from the beam engine build.
I plan to lap the housings, install a thrust bearing behind the chuck, and make a drive pulley. I have a spare 12mm shaft ER 16 collet chuck, which will probably be used more often than the 4 jaw chuck. Then a new handle for the longitudinal feed, a paint job, a motor and belt…
I have a disease, and I do not know its official name, but it involves a compulsion to buy and collect lathes. At last count, I had 9. Varying from a 6mm Boley jewellers lathe, to a 2 tonne 400mm swing behemoth which occupies a large space in my workshop.
Well, now it is 10.
I noticed this one on Ebay, and thought that restoring it might be a nice project. (that is, after finishing the triple expansion marine engine, the Burrell traction engine, the beam engine and the Bolton 7 horizontal engine. Plus tidying up the workshop. Plus selling off the remaining farm machinery. And all of the jobs which SWMBO has lined up for me.)
It is an Australian made (I believe), TNC lathe with 6″ between centres, and a swing of about 3″ (centre about 1.5″ above the bed). I paid the “Buy It Now” price of $A150, because I lusted after it and did not want to risk missing out in auction bidding. Plus $A40 rather exorbitant postage, considering that it weighs only a kilo or so.
It needs mounting on a base, a new handle, a drive pulley cluster, possibly a new headstock shaft, a 3 jaw chuck, a motor, and repainting. The paint looks original and is a horrible job. I will give it a new colour, suggestions welcome. The tailstock centre needs regrinding. It is a tiny taper, about 1/4″ diameter.
Lathes.co.uk is not currently available so I do not have much information about the provenance, age, etc. My guess is that it would be 1950’s 1960’s.
(lathes.co.uk is again online, thank you Tony! The TNC was made in Australia under licence, a close copy of the Super Adept which was made in the UK. Still not sure about the age. The Super Adept was made as early as 1937. The Australian TNC was listed after WW2). The brass handles on my lathe are probably not original.
CNC. That is what started this post. Today, I fired up the CNC mill, and made a simple fitting for my Bolton 7, which involved some accurate deep drilling in aluminium. I LOVE CNC!! Drilling 3mm diameter holes through 16mm material, automatically, centre drilling, then deep drilling 1mm peck at a time and automatically clearing the chips, with positional accuracy of 0.001mm. Fantastic! Cannot wait to get more into this.
I needed some extra toolholders for my Boxford CNC lathe, and the following photos show some of the steps in making them on a vertical mill with a horizontal attachment.
The toolpost holder is a Dickson, beautifully made, precise. And it came with 6 tool holders. 6 should be adequate you think? Not so. You really need one holder for every tool that you might use, because with CNC, you want to do the CNC settings in the computer only once. And the Dickson holders are expensive, so I made the extras.
90% setup time, 10% machining.
The columns are tapered on all faces, so are difficult to hold, and difficult to measure.
I did a CAD drawing, to measure the taper angles, and to calculate some extra dimensions.
Then, in order to hold the castings in the milling vice, I made some accurate wedges at the appropriate angles (3 and 12 degrees) in wood and aluminium.
I actually progressed a bit further than the photos show, even roughing out the condensing tank.
These photos are just a small fraction of the many model engines, ships, trains, tools and other projects created and displayed by members and friends of GSMEE.
The GSMEE held its annual exhibition of projects by members and friends, on the weekend of 15-16 November 2014, at Osborne House, Swinburne Ave, Geelong North.
I will post some pictures and videos of some of the superb model engines, boats, ships, tools, aero engines, and even a full size road legal registered steam truck, pictured above. Due to the size of the files and the crap Internet connection available here, I will spread the post over several days.
To continue with the incredible steam truck, made over the past decade by Tom Lord, see the following videos. (sorry, no luck with the upload. I will try again tomorrow)
I bought a 130mm diameter lump of aluminium rod, 460mm long, weighing 16kg, off ebay. It was described as excellent machining material, so I put it to the test. I need a driving wheel for the beam engine.
Today I drilled and tapped the holes for the bolts which secure the crankshaft main bearings. I had accurately marked the bearing mounts in the previous session (see previous photos), and calculated and recorded the DRO (digital read out) position for each hole. So going back to that position for each step in the process was easy and quick. The steps today were centre drilling, drilling the 3.3mm holes, and tapping the 4mm threads to a depth of 20mm.
Centre drilling is done with a centre drill bit in an accurate chuck in the milling machine. Centre drill bits are inflexible and will not wander over the work like an ordinary twist drill bit, The centre drilled hole is deep enough to create a chamfered edge to the hole. All 12 holes are drilled with the centre bit, then all 12 drilled with the 3.3 mm bit, then all 12 are threaded. The DRO positions the work within 0.005mm each time, and the repositioning is very fast, much faster than going to a position doing all 3 processes, changing the bit for each one, then moving to the next position.
The threading was done with a Tapmatic 30 tapping head in my milling machine. See photo. This takes about 10 minutes to set up, but the tapping process for the 12 holes then took about 5 minutes. I use Rapid Tap lubricant for tapping, even in brass. I guess that manually tapping the holes would have taken about the same time, but it was so satisfying to see the Tapmatic do its stuff. I use the Tapmatic for any tapping job involving more than about 8-10 holes. Fewer than that it is quicker to do them manually. The Tapmatic has a adjustable clutch. I have never broken a tap in the job using this machine.
Incidentally, I have decided to use nuts and bolts and screws and studs in preference to metric cap screws for this model. The appearance wins out over practical expediency. So why the metric threads for this job today? The specified thread was 5/32″ which is 3.96mm, so I decided to go with the 4mm metric, for which I have the tools already.
The next Lake Goldsmith Steam Rally is on November 1-2, near Ballarat, Victoria, Australia. Google it for information and directions.
As well as the usual cornucopia of all styles and sizes of steam and other antique engines, including the massive 90 ton working steam shovel, and the working steam sawmill (see older posts on this site for videos), the rally is making a feature of CATERPILLAR machines.
I will be there. Along with many many other machine addicts.
Today I received a 16.6kg package by courier. It was too heavy for the regular post. It contained the castings for the model triple expansion steam engine, which I am hoping to build in the next year or so. I am told that on average this model takes 3000 hours to complete. That is a scary thought. Almost unbelievable. But when I calculate how many hours went into the much simpler single cylinder beam engine (maybe 600-800), I guess that it is not an unrealistic estimate. Just as well that I am close to retirement age.
The castings were made in NSW Australia, and supplied by Kelly Mayberry at EJ Winter.
The annual “Royal Geelong Show” was held last weekend. It has been held for the past 159 years. Farmers exhibit their best cattle, pigs, sheep, alpacas etc and produce, there are various equestrian events, tractor pulls, Lanz bulldog races, dog breed competitions, and all of the side shows, show bags, and amusement park rides which accompany most agricultural-regional shows.
At the show grounds, Geelong is fortunate to have a well established antique engine display, featuring many steam powered stationary engines, traction engines, steam trucks, tractors, etc etc., many which live there permanently, such as a ships triple expansion steam engine, and many which are brought in just for the show.
There is also a model engineering display, of dozens of working, steam powered small engines. It is always a source of fascination to the many visitors.
A competition is held for recently constructed models, and I was very lucky and thrilled to receive the first prize for the Bolton 12 beam engine. Second prize was for a rebuilt antique pressure gauge, and third for a Stuart twin cylinder “Victoria” stationary engine.
Yesterday I cut some metal on the CNC mill for the first time.
I used one of the canned cycles built into the CNC controller, and faced and squared off a lump of brass which will be used for a hot air engine (The Ridder “bobber”).
Despite multiple readings of the manual, I got confused about which units required minus signs, and which ones the machine automatically assumed were positive and negative, and consequently, despite resting my hand on the emergency stop button in case such a contingency occurred, the head crashed straight into the milling vice, breaking 4 carbide tips and leaving a permanent love bite on the vice as a reminder of my incompetence.
After some expletives deleted, I re-entered the numbers, and next time, the machine went through its motions gracefully, purposefully, and quietly, leaving me with a nicely shiny and squared lump of brass.
It was so impressive, that I repeated the exercise, just for fun.
I had checked the squareness of the mill head to the table, and it was all within 0.01mm in 100mm, so nothing was altered.
I had bought a Z axis probe from CTC Tools in Hong Kong, and that was easy to use and accurate, for $a100.
Next step, to hook up a computer and try to download G code programs. Watch this space.
Another day, another problem solved….
I am sure that these ramblings are incredibly boring to everyone, so understand that I am recording them for my own benefit, as a diary, as much as for the interest of anyone else who might be thinking of leaping into buying an older CNC mill.
So today I looked at the lubrication pump.
The manual says that it operates automatically on machine startup, then every 30 minutes, as long as the oil pressure is not too high. But the pump showed absolutely no sign of functioning at any time. And the ways and ball screws were totally dry until I lubricated them with an oil can.
Today I spent hours tracing wires and looking at relays, until my friend Jason S, who is a machine designer, came and had a look for me. He put a multi meter on the wires, and everything seemed intact. Then he identified the appropriate contactor (which I gather is really a big relay), and held it in, and lo and behold the pump worked. So the problem was with the pump controlling mechanism. Then Jason surmised that if he had designed the mill, he would have had the lubrication pump working only if the ball screws and ways were actually in use, not just if the machine was switched on. So next test was to watch the pump with the ball screws activated. Lo and behold the pump worked! So what was the problem? Why was the oil not coming through?
We disconnected some oil lines, and they were dry. So we manually pumped the lubrication pump until the lines filled, (i.e. primed them) and tried the lubrication system again, with the axes working, and it worked!
So the bloody manual was misleading. The lubrication system does not work when the machine is switched on. It only works when the ball screws are operating. And the machine has been out of action for so long that the oil lines had dried out.
Another gripe with the manual, was when I tried to get a canned cycle working (dry run, with no work piece or cutter). I followed the instruction steps exactly, and nothing happened. I retried, with the same result. I tried another canned cycle… same result. Then Jason arrived, and followed the steps.. same result. Then he said “what is that DATA button for? I had no idea. It is not mentioned in the manual. So we tried pushing it, and halelujah, the canned cycle worked.
So why was it not mentioned in the manual ?????
Do people who write manuals, ever test their own instructions? Or try them with an end user???
So bloody frustrating and such a waste of time.
(note added a few days later… I found the DATA key described in a different section of the manual. My mistake, it was there all of the time. If I had read the manual from start to finish entirely, and remembered the entire 150 pages – or whatever – I would not have had the problem. Silly me. )
Anyway, another step towards making some chips.
So now for the final test, the hookup with a computer using a serial port. Fortunately I have an old computer with a serial port, and I will hook it up soon.
Z axis problem fixed!
My friend Stuart T methodically checked the wires and connections, and diagnosed a problem involving the Z axis encoder. He resorted to removing the encoder, to look at it more closely, and said ” that came off a bit too easily. I wonder if the shaft is connecting properly”. Sure enough, the shaft was loose, which explains the bizarre Z movements followed by a total loss of position information. Someone has joined the 6mm shaft to a 1/4″ socket, and it had probably worked loose during the transport from Echuca to Geelong.
So we quickly made a sleeve to join the 6mm shaft to the 6.35mm socket, tightened it all up, soldered a few wires which broke during the inspection, and hooray it all worked perfectly. Hallelujah.
Oh, and that $20 Chinese hand wheel. It was 10 mm thicker than the originals, and looked out of place, so I chucked in the the lathe, and turned it down to the same 18mm thickness as the originals. It was made of hard plastic-bakelite material which smelled really offensive while I was machining it, and was very abrasive. Tool steel lathe bits were just worn away, but a carbide insert tool coped OK. The reshaped hand wheel looks and feels much better.
Just the oil lubrication pump to fix, then I can start making chips.
I need a wiring diagram for the Extron mill.
It is a Hafco badged machine, but Hafco (Hare & Forbes) do not have wiring info. The Extron factory in Taiwan has not replied to my emails. Hare & Forbes apparently contacted the factory, and also drew a blank about wiring info.
That is pretty unimpressive. The machine is only 17 years old. In built obsolescence? Just not worth while supporting older machines? If it was a US or European machine there would be no problem getting info. It seems that this Asian factory has a different idea about what constitutes support.
Fortunately I have an expert friend who will, I am confident, be able to work it out.
The replacement folding handle hand wheels arrived from Hong Kong today. I was slightly disappointed in the quality, but then, for $a20 each, including postage, I am not complaining. They are close in appearance to the originals.
Pneumatic draw bar. The draw bar was not functioning at all. One of the valves was completely corroded, so I rebuilt it, making a new rim from brass and attaching it with Locktite. The draw bar now functions, but it leaks air badly. A gasket needs replacing, and I will renew that. But if it is still unusable, I will buy a new air draw bar.
I turned on the mill for the first time today.
It booted up, and self tested OK. The servo motors and spindle work fine, and smoothly. The axes move up to 4000mm per minute. The spindle runs quietly up to 4000rpm. (not immediately. I ran it for 10 minutes at a low speed as per the instructions). There seems to be some limits to the travel on the X and Z axes, not related to the hard limits. There must be some soft limits set incorrectly.
All of the ways were dry. There is an automatic oiler, with plenty of oil in the reservoir. I used an oil can to lube all of the ways and the ball screws, because I am not sure if the auto oiler is functioning. It is meant to operate on startup, and then every 30 minutes. Another item to check.
This mill is an Extron, with 1000mm travel on the X axis, and approx 500mm on the Y and Z axes. It is big (for me) heavy and smooth. I expected that it would need some attention because it has not been used in years. So far the revealed problems have been with the peripheral items and cosmetics, and not the major components or the electronics. So far so good. I will post some pics soon.
I was on call over the weekend, so I had today off, and spent it in the workshop. It was cold. Jumper plus oilskin cold.
I crow-barred the space for the new mill, levelled the mill with a machinists level. One foot was missing so I turned up a new one… 75mm dia, 16mm thick, with a 20mm dia recess to accept the levelling bolt.
Then I started to tidy up the awful paint job, scraping paint off the machined parts, and using my Dremel to wire brush it off plastic parts. Starting to look more respectable.
Then I found a hand wheel control lever stop made from a rolled tube which had broken off at surface level. It was hardened, as I discovered when I tried to drill it out… changed the drill bit to mush. So I used the Dremel with a carbide bit to grind it out. That worked, but it took a lot of time, and I ended up with an irregular hole which I then drilled out to 5mm and tapped 6mm. I have inserted a temporary 6mm cap screw as the stop, and it works but looks a bit gross. Needs a tidy up.
The 3 phase lead does not reach my converter, so I have to replace it with a longer one. The plug is new, so I will re-use that. I have some 20 amp 4 wire lead, so I will use that. Maybe next weekend I will get to fire it up. Saturday is out though. Geelong – Hawthorn AFL game takes precendence.
I need to make some T nuts to suit the 18mm T slots. They are bigger than any machine I have previously owned. I will tap them to accept 12mm studs, rather than the recommended 16mm studs. I already have the 12mm studs, and I cannot see that I will need the bigger ones. If i was to use the table capacity of 900kg the big ones would be useful.
Today I took a half day off work, and booked a crane to lift my CNC mill off the truck onto a steel plate outside my shed, from where Des and I rolled the 2.8 tonne machine inside.
It has been under a tarp, in the rain, for the last week, so I am happy and relieved to have it indoors. Some surface rust was rubbed off. And I spent a few hours cleaning it up, oiling it, doing minor repairs and getting it ready for turning on soon.
One of the hand wheels has been broken and I have ordered replacements from Hong Kong. The pneumatic drawbar is not working. I have pulled it apart, identified the faulty part, and I will attempt to make a new part.
The mill is too big for where I have installed it. I have removed the side tool tables, but it is still too big. So I have some further crow barring of machines to make space.
I hope to connect it to the electrons in a few days.
It has been repainted at some stage. An awful paint job which has gone onto machined and plastic surfaces. I intend to spend time tidying it up, and one day I hope to repaint it more carefully.
Now I have my fingers crossed that the electronics and ball screws will work OK. It is a bit of a gamble.
I have been looking for a CNC milling machine for over a year. My requirements were that it had to be affordable, not too big for my workshop, not too big for my 3 phase converter (max 5hp), use Mach 3, and be in reasonable condition.
What I got was good value I hope, big, 6hp, does not use Mach 3, but I think that it is in reasonable condition.
See photo below.
It is an Extron (Taiwonese) 1997 model, vertical CNC mill, which uses a Fagor controller (not Mach 3), weighs 2.8 tonnes, and is BIG. Too big really, and I hope that I never have to move it again. It required a crane to lift it onto the truck which I borrowed from my neighbour. The truck (and me now, and the mill) smell of pig shit, because that is what the truck was used for the day before. But the 550km round trip to pick it up was completed safely. Now I have to organise a crane at my shed to lift it onto a steel plate outside my shed, from where I can push it into position (on rollers).
That was the longest truck trip I have driven since getting my heavy rigid licence a few years ago, and I feel quite proud to have completed it without a problem.
I will fire the mill up next weekend. Wish me luck.
I have heard that the castings for the triple expansion marine engine will be arriving in the next week or so. That is good news after waiting since the order was placed in January.
In the meantime, I have bought some castings and partly made components for a Burrell Traction Engine. It is 1.5″ scale, and I obtained some 1.5″ plans from EJ Winter for the Burrell. Unfortunately, one mans’ 1.5″ is anothers’ 1.45″ and the plans are not exactly correct for the castings! What would have been a difficult build, has turned into a very difficult build. So I have put it aside and will tackle it gradually. The plans will be some use, but as well as the difference in scale, there are differences in the designs. So I will have to make it up as I go, to a considerable extent.
My metal working club has promoted a competition for 2014, and it appeared to be a fairly simple build, so that is what I am currently machining. See the progress in the photos below. It is a Stirling heat engine, designed by J Ridders. You can see one working on the Ridders web site http://heetgasmodelbouw.ridders.nu
I bought these Burrell Traction Engine castings and parts off ebay recently, because they were cheap, and my triple expansion engine castings still have not arrived!
The traction engine is 1.5″ scale, and the finished model will be about 500mm long.
The complex copper sheet part in the middle of the back row has been partly riveted and soldered. The sheet steel parts on the right hand side have had some of the fittings bolted to it. I am guessing that 95% of the build is yet to happen.
There were no plans, but Kelly Mayberry at EJ Winter has a 1.5″ Burrell in his catalogue , so I have purchased those plans hoping that they will suit. Kelly tells me that the Burrell is a fairly difficult build, so that is a challenge.
There are hundreds of rivets in this engine, so riveting will be a new skill to acquire.
22 July 2014. The plans have arrived, 9 sheets of them. Like all plans, the initial browse showed a daunting mass of detail. Some of the sheets have imperial measurements, so first task is to convert those to metric. The boiler particulars were upgraded to modern approved standards a few years ago, so they at lest are already metric.
The next task is to get the plans laminated, so they remain readable in the dirty workshop environment.
Then to starting the fun bit… the machining…..
There are many such models, working, on U Tube, and worth a look.
Today I attended this steam rally near Ballarat Victoria Australia.
The weather was cold and wet, and accompanied by my brother Peter and friend Stuart S, we drove the 2 hours from home.
I had only a vague idea about what to expect, but it was so fantastic that I will be definitely going to future events there.
To explain, Lake Goldsmith is farm land, in pretty undulating countryside. 38 acres have been set aside for steam enthusiasts, and dozens of sheds of various sizes have been put up and filled with workshops and machines. Many of the steam engines were outside, so we were grateful for the shed displays whenever the rain set in.
There were hundreds and hundreds of steam engines, boilers, traction engines, early kerosine farm engines, vintage tractors, model engines.
There was a working timber mill, cutting huge pine slabs, powered by a superb steam engine. See the videos.
The star of the displays, is a working 90 ton steam shovel
This grand parade deserved more than my iPhone video. The battery failed after only about 1/4 of the parade. It was amazing and inspirational, and uplifting.
Absolutely must see.
Next grand parade in Nov 2014. 1st and 2nd. I WILL BE THERE.
Showing the 80 degree steel knife edge, and the 90 degree V groove in the redgum.
The folded steel is in the foreground
This contraption is a toolrest for a benchgrinder. it was an early project when I started metalworking-machining, and was made mainly on a milling machine, and lathe.
The tool to be sharpened on the grinder (lathe cutter, chisel, screwdriver, saw blade etc) rests on the top platform. The top platform can be adjusted to any angle in 3 dimensions, using the brass handles. The 2 brass knobs are to present the work to the grinding wheel, and are graduated in thousanths of an inch. Sounds complicated and it is.
Designed by Harold Hall, with plans and instructions in his book “Milling, A complete course”.
The wine glass is for scale only. Although the level went down during the photography session. Must have evaporated.
I have nickel plated several components of this tool ,because of surface rust.
A few snapshots from my iphone while I was doing the first nickel plating.
Just a bit more finishing on this boiler.
At the chimney end there is now a removable cover to provide access to the smoke box (the round aluminium cover with the brass lever nut), and a sliding door to provide access to the firebox.
You can just see the Bolton 7 engine behind the boiler. They are both sitting on a marble shelf above the fireplace in our living room. I was amazed when SWMBO said that it could live there.
My 18 month old grandson loves to be lifted up to the “teamengine” so he can turn the flywheel.
The ring roller is used to form strips of steel or pipe or rectangular or square section into curves or circles. This home made version will handle up to 1/2 inch thick and 4″ wide. (12.7×100 mm). It is powered by a 1/2 HP electric motor, geared down 1:60. The chain drives the bottom 2 rollers. The top roller is a cluster of old ball bearings. The top roller is adjustable for height, with 2 spring loaded 16mm nuts. The case is 16mm plate, bolted together with 10mm cap screws, so it is reasonably heavy duty.
I added the infeed and outfeed rollers as an afterthought, to avoid any possibility of the work twisting in the machine.
The video shows making a semi circle of 25×25 SHS, in a diameter of approx. 1.5 meters, but I have made circles as small as 150mm in 12×40 mm mild steel.
The Roller is bolted to a steel bench and is easily removed when not in use. The motor stays attached permanently.
The chain of the Golden Horn.
At least 600 years old. Forged by hand.
ancient or at least medieval, metalworking