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"

Tag: johnsmachines

Getting Ready for Casting

Setting up for casting molten metals into shapes for my model Armstrong cannon.  Still getting ready.

Today I made some moulds for dealing with any left over metal melt.  Not a big deal, but it does have to be done before the first melt.  No point realising that there is nowhere to put the left over aluminium or bronze during the pour.  It has to go somewhere.

So today I made some ingot moulds, in readiness.

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The ends of the moulds are sloped to allow easy ejection of solidified aluminium or bronze.

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4 ingot moulds.  Made from 40mm ID thick wall pipe, with long handles.  The diameter of my crucible is 48mm ID, so any ingots made should fit into my crucible later for remelting.

It seems a long time since I have done any welding, and the welding of these items was pretty ordinary.  But the joins seem water tight, so hopefully they will be OK.

Today I fired up the casting oven, to 850ºC, and the load was some ordinary food tins.  They are the correct diameter for investment moulds.  I wanted to see if the tins would cope with these temperatures. (after removing labels of course).

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3 ordinary food tins, at 850ºC.

It became apparent, that the tin joins were welded not soldered.  And the inside and outsides of the tins were covered with some sort of paint or plastic, because it flaked off.  But the metal cans remained intact.  Admittedly, when hot they were VERY soft, but when cooled they retained their shape, and were quite stiff.   I would be prepared to try these for single use moulding projects.

I have realised that my investment plaster mixing bowl is too big for the vacuum chamber which I had bought.  So I have ordered another vacuum chamber, and waiting for it to arrive before starting a mix.  I am using the delay to gather items like the ingot moulds above.

It will probably be another couple of weeks before I am ready to cast.   Meanwhile my 2mm rivets have arrived at last, so I will get back to the riveting.

Thinking about future exhibitions….

Still recovering from The Royal Geelong Show, where my beam engine and the Trevithick      dredger engine ran for ~8 hours per day for 4 days, and required almost constant supervision. I was very pleased that they did so without a problem.

For future exhibitions I would like to also run the triple expansion steam engine using the vertical boiler, for which I recently made the Southworth boiler feed pump.  And there are occasions where I might run the triple and the beam engine together from the vertical boiler.  That arrangement will occupy a fair bit of bench space, and in this post I am considering options for the arrangement.

But first, I needed a steam outlet manifold to handle multiple engines, simultaneously, and hopefully to avoid a big tangle of pipes.  Here is the manifold.

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The manifold has 6 x ¼” outlets and one 3/8″  outlet.    

Option one lines up the boiler and engine like this….

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Option two is more compact, but ?less appealing.  Pics following..

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The lump of wood under the engine is temporary,  just to give an idea of the heights.

OK, this post is just an excuse to show some pics.  I have decided to go with option one.  It is closer to the appearance if the boiler and engine were actually in a boat, and also will make it easier to add the beam engine to the right of the boiler if/when I run the two engines simultaneously.

And I doubt that I will be able to avoid a jumble of pipework.  The triple has 6 pipes attached, the boiler has more, then there is the beam engine.  And, I will need a water container from which to feed the boiler.  That will be located behind the boiler.  Still considering whether it should be a squarish box on a stand like the railway water towers, or a cylinder on a low stand.   Any thoughts?

 

 

 

Boiler Feed Pump Pumping

Yesterday I reseated the pump valves, reassembled the pump, then tested it on steam.

Most of the following video has the boiler at only 25psi, but I did run it off camera at up to 75psi.

After making the video I redirected the exhaust steam from the pump into the firebox.  It actually seemed to improve the gas flame, maybe by acting as a blower.  Not so sure about this being permanent though, because the exhaust steam contains oil from the displacement oiler, and I dont want that oil to be deposited in the firetubes.

I will make a water tank to supply boiler water.  Maybe the exhaust steam could be passed through a heat exchanger in the tank, so the boiler feed water is preheated.

(if the video is not showing, click on the https link below)

 

First Steam for Boiler Feed Pump

 

 

 

A European Workshop

Most of the workshop pictures so far have come from Australia, and one from UK.  This one is from Holland, sorry Huib, the Netherlands.

Interesting differences.  Huib built his own workshop, and he has some nice gear.  All of these photos came upside-down.  Funny how they consider Oz to be “down-under”.  Obviously their reference points are wrong. THEY are the upside-down ones.  I mean, we are walking upright, right?  They must be upside-down!

 

Hello John,

Here finally my contribution to your workshop series, as always I might want to show and share too much with others, that’s why I want you to show  what you can support and is in line with the possibilities you have on your blog. 

See if you can make one blog part of it or cut it into pieces. That’s up to you. I transfer the pictures with WE TRANSFER to you, as it is right you got a mail with the link to download the pictures.

It looks like the pictures that it is all clean and tidy maybe but appearances are deceptive, most of the time it’s not so tidy for me either, for the pictures I cleaned it up.

I have tried to be as complete as possible but if there are any questions please let me know.

I built the barn myself, so as the floor plan was drawn. First I built room 1 which is completely isolated and where I can work during the winter, there are also the most expensive machines. 

Later on I built room 2, to store also the wood for the stove. Finally, 5 years ago I built room 3, the largest room where also other things are stored as only hobby stuff, also our bikes and everthing els.

Room 1 is the room where I stay most in, coarse work I do room 2, such as sawing, sanding and coarse drilling.  In room 3 I mainly do business that need some space, the large, homemade workbench is a good tool for that. And as you can see, I can’t throw anything away and I keep everything I think of that can be useful in the next hundred years.

The photos contain references to the machine and the space where they are located.

I hope you like the total information.

Kindest regards

Huib

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The thing about Holland, is that they HAVE to make the world’s best pumps.  Otherwise they are under water.  Much of the country is below sea level.

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Now, that is nice!

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Ahhh!

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Ahhhhhh!

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Nice!  But I will stick with CNC.

Huib also sent a video of his steam plant.  Unfortunately I do not have the space to post it, but if Huib can remember the YouTube address I will include that later.

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Storage is always a problem no?

So, thank you Huib, for sharing your workplace with us.  It is very interesting to see how other model engineers work, and their equipment.  I have posted only a fraction of Huib’s photos, due to space limitations.    I hope that the chosen shots are of interest to my readers.

ps.  Huib, I found the YouTube video…Very nice work!

 

Bolton Steam Museum

I was a bit unsure about visiting this one.  A smaller museum, and I knew from the web site that it was not a steaming day.  But it was only a half hour drive, so off I went.  I arrived at the address, and there was a supermarket, but in a corner of the supermarket block there was a tall, old,  sizeable red brick building with no windows.  And a sign… “Bolton Steam Museum”.

In I wandered, and a gentleman in overalls approached.  This was a volunteer working day.  But Ian (apologies if I got the name wrong), stopped his task and spent over an hour showing me around, explaining the finer points of his babies, starting some of them on electric motors to demonstrate the movements, then invited me to a cuppa with his mates, where there was further discussion, mainly about rope drives and stone engine bases.

No parking or entry fee on a non steaming day, (but a donation was appreciated).

The machines were not the monsters of Kewbridge or Kempton pumping stations.  They were mostly from the industrial age of the midlands 1840-1930, powering textile mills, sawmills, and factories.  Some were quite big.  All were beautifully restored and presented, and for once, the descriptive labels had lots of information about the physical characteristics and histories of the engines.  A nice aspect was the elevated walkway down the centre of the room, allowing a good view above the engines.

Some photos follow.  Not as many as the museum deserves, because I am nudging my  Wordpress limits.

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The twin beam engine of 1840 is the oldest engine in the museum. It started life as a twin, but when higher pressure steam became available it was converted to a compound twin.  Note the non identical con rods.  That happened during the conversion to compound.  Partly seen is an excellent collection of engine lubricators.

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This is a “non dead centre” engine.  It has 2 con rods, one for each piston, but only one crank.  Watch the video below and see if you can figure it out.  It ran 100 looms in a textile mill.

 

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Two of the barring engines.  These were small steam engines which were used to rotate the flywheel of a much bigger engine, to its correct starting position.

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For the first time ever, I saw rope drives in action.  Rope made of cotton was preferred, but these days sisal is usually used.  Each rope could transmit 54hp if made of cotton, 30hp if sisal.  They worked in V shaped grooves, and hung rather loosely between the pulleys, the weight of the rope wedging the rope into the groove.  The splices, joining the rope into an endless loop were made by specialists, on the engine, and unlike marine splices, barely increased the diameter of the rope.  The splices which I saw extended over about 2 meters of the rope. 

This museum is another gem.  I have described only a few of the 24 major items on display.  There are many more, including engine lubricators, gauges, and valves.  It was well worth the stay in Manchester, and more than made up for my disappointment at the  Museum of Science and Industry.  Try to see it on a steaming day.  The dates are published on the website http://www.nmes.org

Also, the 36 page “Souvenir Museum Guide” is the best guide of its type I have encountered and contains detailed descriptions and colour photographs of the major exhibits.  It is a steal for £2.  The History of the Bolton Steam Museum is 64 pages, crammed with photos, and after a quick browse I am looking forward to reading it.  Also IMO, a steal at £3.

Sincere thanks to the volunteers who shared their enthusiasm for steam engines with me today.  I do hope to return one day to see the engines running on steam.

 

 

Next Project

The Trevithick dredger engine model is almost finished.  Currently applying some paint.  And getting it ready for the final boiler inspection.  I am guessing about 2 weeks.

I have chosen a spot in the house where it will sit, and will post a photo in due course.

A few people have been asking if I have decided what to make next.  In terms of a major build, the answer is no, I have not decided.  I have considered a few possibilities.  Those possibilities include a model of Stephenson’s “Rocket”, Trevithick’s “Catch Me Who Can” or “Pen-y-darren engine”, a Shand-Mason fire engine, or even another cannon.

What I will do, is to complete several unfinished projects, and if a major project becomes obvious, imperative, then anything is possible.

The unfinished projects include…

  1.  An Arduino controlled rotary table.  The mechanicals are made.  Just need to dive into the electronics.
  2. The Southworth steam powered boiler feed pump for the vertical boiler.
  3. The CNC controlled tool post milling attachment for the Boxford CNC lathe.
  4. Paint the Bolton beam engine.  Lag the cylinder.  Install a cylinder oiler.
  5. Finish the triple expansion model marine engine.  The lagging, the piston rings, the gaskets, the oiler and oil pipework, and painting.

Looking at that list, I really do not need to start another major project.

And sometimes it is nice to sit back, and enjoy the glow and satisfaction of previous projects.  It does sound rather self satisfied, no?  So here is a selection of videos, mostly first runs of newly completed projects.  Most are YouTube links, but one or two will run directly.

This was the first model steam engine which I made about 5-6 years ago.  It is a Bolton 7 single cylinder mill engine, and this was the first occasion I had run it on steam.  It was a very exciting moment, seeing it actually running on steam.

Next came the Bolton 12 Beam Engine.  Still a crowd favourite.  The beard was ordered off by SWMBO not long after this.

Then a couple of Stirling engines.  How they work is still a mystery to me.

 

Then the problematic, difficult triple expansion engine, which took 3 years and several extended breaks to get to the working stage.  Still not finished completely.  Stuart Tankard’s boiler.  Since then I made a vertical boiler.

And somewhere in there I made this little reversing engine for the club competition.  Alas, it failed in action.

And 3 cannons came out of left field.  They started as a CNC project, but then took on a consuming interest of their own.  About this time I saw the necessity of learning how to put together a video.  Still learning.

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The 6″ vertical boiler.

And finally the Trevithick dredger engine.  The historical aspects of this engine, the genius of Trevithick, the fact that the engine works…. has been marvellous.  The engine is looking quite different with some paint applied.  And the propane burner is significantly better than appears in this video.

So, if you are still with me after all of those videos, congratulations on your stamina.  It is  therapeutic to take stock sometimes, and to wonder about where making all of these engines is going.  It was not to any plan.  Still no plan.  Just enjoying the moments, the days.

Trevithick Blower

I am sure that my readers will have gathered by now that I am not an expert.  At least in matters of metalworking, model engineering etc.  I am, or was, an expert in my profession, some years ago.  But this blog is about how a non expert copes with  problems in model engineering.  It aims to be entertaining, occasionally helpful, and a diary of my workshop doings.

When Trevithick designed his revolutionary engine, (“revolutionary” in all senses), he arranged for the exhausted steam to be funnelled into the chimney, after pre-heating the boiler feed water.

It was a matter of convenience apparently.   Rather than ejecting the spent steam directly  into the air, it would go up the chimney, away from the operator.

But almost immediately it was noticed that the fire in the firebox was more vigorous, hotter, more efficient  Thus was born, the steam engine blower.

So I made the junction between the exhaust and the chimney as per the plans, at an angle of 90 degrees.

But, I noted that on the exhaust stroke, the fire in the firebox spluttered, and occasionally went out altogether.

In more modern steam engines, the exhausted steam is inserted into the chimney, but parallel with the chimney, not at a right angle.

So, I thought, do I stay with the Trevithick design, or the more logical more modern design.  I was having problems with my fire, so the decision was easy.  I would pretend that Trevithick would adopted this design.  Maybe he did.

But that meant breaking the silver soldered join, inserting a new angled copper tube, and rejoining it all.

 

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As Trevithick designed it on the left and on the right as I remade it today

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Right is the exhaust piece between the preheater and the chimney.   Left is the new blower tube, which must be joined end to end, and then poked up the chimney.

This was going to be tricky.  And end to end join of 2 pieces of 9.5mm copper tube, and the join being right where the tube enters the chimney.  But then I remembered a tool which had sat unused for several years…

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OK,  This is probably very old hat to most of you.  But it was exciting to me.  First I had to assemble the tool.   Sorry I missed the camera.

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I decided to solder the pipe join first.  Rested the end with the flange on a lump of scrap brass, to act as a heat sink, and protect the flange join.

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That worked well.

Then I soldered the assembly into the chimney, after bolting all of the parts into their positions.  Sorry.    Forgot to take a photo.    But it all worked well.   I like the tube expander, but it needs some extra fittings so it works on smaller tubes.

 

 

Trevithick Dredger Engine. Almost There.

Firstly some pictures.

 

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So, I have reassembled the engine and the burner and the base.

Did you notice the base?

No?   Excellent.  That is the idea.  A nondescript matt black base which is barely noticed.

Yes?  OK,  well it must be OK.

Then a trial of the burner inside the firebox, using the changes which have evolved over the past few days.

During the video I am constantly changing the propane flow, and there is a clear “sweet spot” point where it looks really good, and feels very hot.  I have not yet tried to steam with it.

Beware of Greeks Bearing Gifts

Well, this one is OK because it came from a Hollander.

One of my blog readers, Huib, decided that I would be the recipient of some of his workshop items which he says were surplus.  This was as a thank you for johnsmachines.com.

So, a parcel arrived yesterday, and after a quick look inside, I decided to make a video of opening the items, and showing you.   It was great fun for me, and I hope that it will be entertaining for you.  It is the biggest file which I have uploaded, so give it a few minutes to open.

Oh, any other readers who would like to send me surplus tools or other interesting bits and pieces….  please feel free.  If Haas, or Hardinge would like a review on one of their machines please send it and I would be happy to do a review.

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

Well, I was really not expecting this.

After all, the engine was running well on compressed air at 30psi, and the burner appeared to have a good flame.

And Stuart was coming to be involved with the big event.  So nothing could go wrong!

I set up the iphone on a tripod.  Checked the light.  Oiled the bearings and slides.  Filled the boiler.  It takes 2 litres of water.  And hooked up the propane.  when Stuart arrived I lit up the burner, and sat back to see how long it would take to raise steam.

Some steam leaks were expected, on this first steam run.  Leaks don’t show on compressed air, unless they are severe.  As the water heated up, some leaks appeared.  The water feed clack valve and the sight glass were bad.  The clack valve just needed some goo.  Later I disassembled the sight glass, and cleaned the valve, with some improvement, but more work needed.  Or a new sight glass valve.  A couple of other trivial leaks were easily fixed.

So we watched the clock, and checked the temperatures.  Ot took 20 minutes to start raising steam.  That is a bit slow.  Eventually it reached 20psi, but the pressure refused to go any higher, despite fiddling with the gas and air controls.

At 20psi, I opened the throttle and gave the flywheel a swing.  You can see the result.

After that, we let it cool down and fixed the clack valve leak.  The sight glass valve leak was looked at later, but could not be fixed simply.

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The burner flame.  A bit feeble.  A bit yellow.  And occasionally blown out by the cylinder exhaust gas puffing into the chimney.  Stuart says that I need to angle the cylinder exhaust gas upwards in the chimney.  Apparently Trevithick did not do that on the full size models, but perhaps he should have.

The burner was definitely not up to the job, so in this last video, it got some assistance.

It does go!   Just needs a few tweaks.  Lovely sound.

Sight Glass on the Trevithick Boiler

Not real happy about this one, but it is necessary if I am to run the dredger engine in public, at club meetings etc.

The original dredger engine had 3 taps to check on the boiler water levels,  like this.

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An earlier stage of construction, using taps to reveal the boiler water level.

Unfortunately that setup is unacceptable for boiler certification, so I have installed a sight glass using the same penetrations.

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The red colour does not help.  But when I run the engine on steam, this is what will be seen.   Functional, but nothing like the original.  If I use compressed air, or steam from an outside boiler (i.e. my burner not being used), I can reinstall the taps.

The sight glass is a bit short, but it should comply with the regulations.

I have spent another half day experimenting with different spring configurations, so that the safety valve releases at 40-50psi.  Eventually I decreased the coil pitch of the spring, and the valve now releases at 45-50psi.  That will do.

A Tour of the Model Dredger Engine

Now that I have a tripod for my video camera (an iPhone), I have become a bit more enthusiastic about making videos.  Terrible standard of video compared with Joe Pieszczynski, and This Old Tony, and Stefan Gotteswinter, but maybe better than just text and photos.  I will be interested in your responses.

The Dredger Engine is still not quite fully made, but while I had the video set up for the spring making exercise yesterday, I added the following.   It is totally unscripted, and unedited, so there are errors.  “pressure valve” instead of “pressure gauge” for example.  Have fun counting the errors.   The final 30 seconds is me having difficulty turning off the camera!

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Read this response to Antarctic Weird

I received this email today.  I am posting it with Jennifer Edwards’ permission.  Just reading it made the hairs on my neck stand up!   
BTW, I will continue posting until my current subscription runs out in a couple of months.
John,

sorry to see you go. I was enjoying your wit as well as great machining skills. I have the same issue with a web site I maintain for my partner. The bastids nickel and dime mw to death, send me renewal notices a year in advance, and try to sell me security crap with e-mails spouting fearful phrases that always seem to include the words “haters, Spammers, and internet thieves. I do not blame you for pulling out.

When reading about your Antarctic pictures it reminded me of an experience I had when I was about 18 years old. I have not told this to many people over the years simply because every time I do they look at me like I am crazy, however you seem to have an open mind so I will risk never hearing from you again….
 
The event occurred over forty six years ago. There were three of us present, and unfortunately I am the last surviving member of the group.
 
It was Late October 1972,  the Friday evening before Halloween in Southern New Jersey. My future X, my little brother, and I were on our way from our home town of Cinnaminson to our family cabin on Bamber Lake, in the Southern New Jersey pine lands. I was driving. Our route took us on unimproved two lane back roads that normally only see farm traffic. The weather was a crisp and clear October evening with unlimited visibility.
 
About a mile east of  Vincentown I rounded a bend and there it was in the north west corner of a small rectangular field of maybe three possibly four acres. The road ran the length of the field. The field was surrounded by large old oak trees along the West and the North. The road ran along the south boarder and then curved along the eastern boarder. The field was long and narrow.
 
As I rounded the bend a brilliant light caught my eye. There in the north West corner of the field was a large object hovering. It was shaped like a bell, about 40-50 feet high and maybe 70-80 feet in diameter. Only an oval dome at the top of the bell was above the tree line. 
 
Upon later reflection we realised that the location of the object was less than three miles to McGuire AFB. It would have been a great vantage point to observe the airfield.
 
I noticed that there was a berm along the edge of the field which I drove up on to put my headlights on the object. We sat in awe for maybe 20 seconds at which time the three of us exited the car to get a better look. Please note, to this day whenever I think of that evening the hair stands up on my neck, it was that profound an experience.
 
The object was hovering, maybe ten feet off the ground. It was shaped like a bell with a convex bottom. It was a dirty whitish grayish in colour. The apex had a brilliant white light which radiated beautiful, quickly pulsing, beams of light in pure crystalline colours, vivid blue, violet, red, and green. The beams seemed to come from a brilliant blue white point just below the oval disk on the top of the “bell” to a row of the same colour of white lights evenly spaced along the rim, then from those white spots to another white light in the centre of the convex bottom of the craft.
 
Maybe ten years later I saw my first laser light demonstration, it was that type of pure crystalline single wavelength light that instantly reminded me of that object. In fact the hairs on the back of my neck and on my arms stood straight up.
 
As it hovered it made a sound akin to a very large saw mill blade swinging. I cannot find other words to describe that whirring sound other than a saw mill blade spinning.
 
The three of us were standing in front of the car, headlights on the object just gawking at the objet. This went on for maybe a minute possibly a minute and a half. 
 
BTW I am a licensed pilot and also a highly experienced sea captain, I am a good observer, with an eye for size and distance. We were maybe 175-200 feet away from the object.
 
At that point I alone started walking towards it, my x and brother were too awestruck to move. When I got extremely close, less one hundred feet, probably more like seventy five feet away. The size of this thing sank in. It was the size of a small house! I started smelling that lightning storm ozone odour,  began getting a strong metallic taste in my mouth, and felt tingly on my skin. This scared me so I made a slow retreat back to the car never taking my eyes off the object.
 
When I rejoined the other two we stood there for maybe two more minutes, just looking, listening to the whirring, not speaking beyond a few “wows” and “oh my gods”. Then it hit me, I had a Yashica 35mm camera loaded with asa 400 film and sporting a 200mm lens on the front seat. 
 
I reached into the car, grabbed it and began fumbling trying to remember how to focus  it when you could not see thru the view finder. It was one of those old 35mm cameras with all manual controls. I was unfamiliar with the camera and fumbled around. I never did get a shot, something I truly wish I had done, as anyone I related this story to since that day some forty six years ago has either thought I was crazy or simply humoured me.
 
Any way, as soon as I aimed the camera at the object it seemed to immediately react to the threatening move of pointing what may have been perceived as a weapon at it. 
 
iI’s sound began to change. It got higher and higher and higher in pitch and volume until it was just a deafening hiss, like high pressure steam being vented thru a small aperture. 
 
Some years later in San Diego I had another hair standing up moment when I went to work with a fixed hard disk manufacturer. We had tanks of liquid freon that were huge ultrasonic cleaners used to clean the 18” stainless steel disks before transferring them into the clean room for final assembly. The first time I turned one on and heard that hissss there went the hair standing up again. That was the frequency of the sound. This had to be around 1982.
 
Sorry to digress, any way the sounds frequency went up, the pulsing lights became gradually brighter and more brilliant until the entire craft was one very bright white fuzzy bell. The craft slowly rose to an altitude of maybe 150 feet. It slowly went on paralleling the road heading northeast about 100 feet to the west of the road.
 
We jumped in the car and followed. We were able to keep up with it for maybe a mile and a half  while it slowly accelerated until it finally had a good lead of maybe several hundred yards. It’s altitude was increasing as was its rate of climb. Slowly at first, but obviously steadily accelerating in what settled in at about a 30 or 40 degree climb.. The road ended in a “Tee” intersection. So again we got out of the car and stood in the middle of the itersection watching as it continued its climbing. We were able to keep an eye on it due to the exceptionally clear sky and the fact that we were way out on the country, so light pollution was not a factor..
 
Finally after another five or more likely six minutes the thing was just another one of the stars in the sky. It grew fainter and fainter, until it was indiscernible from all the other stars.
 
At that point we got back in the car and continued on our way.
 
One interesting point is that from the point where that craft was to the runways of McGuire AFB is only a couple of miles. Back in 1972 the area of the jersey pines we were in had many Cold War installations,Nike missile installations, the Space Track “ golf Ball” and others. There had been a nuclear warhead on a missile that had caught fire and contaminated a very large area with plutonium, the active air base was there as well. Plenty to look at if you were interested In the military capability of a civilisation.
 
For the rest of our lives whenever either of the three of us met, right up to the ends of their lives, we always said ” hey remember the flying saucer”. I have only told this story to four or five others over the years. The blank stares or that look like you are some kind of nutter shut me down.
 
Any way there you have it. I wish you luck with your build, and YES please post a video when it is complete, and send me a link.
 
Thanks again,
Jenny




Jennifer Edwards

6″ Vertical Boiler- Penetrations

Another few hours in the workshop today.

Continuing preparing the parts for the boiler.  Drilled and reamed 9 holes and the bronze bushes which will be brazed into them.  The bushes provide the screw in points for water inlets and wet steam outlets, pressure gauge, water gauge.

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All of these components are just sitting in place, but giving an idea of size and form.

There will be no progress on the boiler for a week, due to forced absence from the workshop.  Child minding the grandchildren.   Hmmm… I wonder if a 2 year old could help in the workshop?   Possibly not a good idea.   Yet.

FOWLER R3 TRACTION ENGINE

Start of the parade of tractors at the Geelong Show.   Graeme and John driving the Fowler R3.   Video by Stuart.

 

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Fowler R3 at The Geelong Show

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I took my Fowler R3 3″ scale traction to the Geelong Show, and here it is on display.

The R3 is a bit of an uncommon traction engine, so I was rather surprised, delighted and awed to find a full size R3 on display also.  Of course I met with the owner and spent a lot of time talking to him and examining the real McCoy Fowler R3.  Apart from the size difference, the similarities were striking.  Even the colour scheme was similar.  And the full size machine was a heavy haulage model whereas mine is a road locomotive.

I found the numbers were interesting

weight     250kg/18tonnes

length 1.5m/ 6m

towable load 250kg/60 tonnes

cylinders 2/2

boiler pressure 100psi (copper)/180psi (riveted iron)

year of build 2016/1911

 

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Me, getting a driving lesson from the owner, Graeme Brown

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The firebox door, throttle, looking forward

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Winch

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Forward/reverse lever

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Water pump, crankshaft driven

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crankshaft with its cluster of big ends and valve rod eccentrics.

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Con rod big end hardware

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Fire box door and water level sight glass

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Fowler R3 heavy haulage engine.  spent most of its working life in and around Ballarat, Victoria, Australia

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Rear wheel hub and winch

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This could be a photo of my engine, but it is not

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Lubricant and tool storage area.  Actually the front suspension and steering drum.  I imagine that the springs are to protect the  gear teeth.

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Not sure that the brass cylinder cover is kosher.

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The wheels hardly dented the grass during the grand parade.

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The engine mechanicals, oiler, whistle, and hose support.

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Boiler inspection hatch, and water intake.

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Belly tank, steering gear

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The engine could be used as a cathedral reliquary

And a series of non-edited videos, to recapture some magic moments.

More Triple Photos

Reader Richard suggested that I include a ruler in some of the triple photos, for a sense of scale, so here it is.

It is approx 300mm long 200mm wide and 270mm high.  Weighs 12.4 kg.

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Triple Expansion Engine Update

Well, almost another whole year has elapsed, and still the triple is not finished.  Come December, and that will be 3 years that this project has occupied my thoughts and workbench.  With a few other projects in between.

Last week I assembled the components, in preparation for the Geelong Show.  GSMEE is a bit light on for new models, and it was suggested that the triple might fill some shelf space, despite being unfinished.

So I bolted it together.  All 429 fasteners!  And stood back and admired it.  It really is quite impressive, complex, and interesting.  So I took some pics.

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This is the condenser side, and the Edwards pump

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The other side is a bit lessy fussy, showing the steam inlet valve, the Stephenson’s links, weigh shaft  and controls.

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And the top, showing some of those 429 fasteners,

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The high pressure valve chest cover.  I will fill those holes where bolts cannot go.

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And the low pressure end, and links for the pump.

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And a close up of the steam valve and weigh shaft.

Not quite ready to run it yet.

It needs side covers for the cylinder block, drain cocks for the cylinders, and general freeing up.  It is still very tight.

Not to mention painting.  I expect that I will paint this one.   No idea of colours yet.

Steam Trains

Two of my grandchildren are identical twins.  Here is a recent photo of one of them.  Not much point showing a photo of the other one.  He is identical.

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Not sure which one this is.  They really are identical.  He is planning to join a circus.

Anyway, I had made a wooden train set for my other grandchildren, and my other daughter, the mother of the twins, suggested that the twins should have one also.   I decided to CNC most of the parts, and it was not much more time to make two compared to one, so here they are.

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The design, slightly modified,  is from a book by Jim Makowicki “Making Heirloom Toys”.  The trains are ready for painting by SWMBO.   She is planning to use wood dyes, and finishing with a clear laquer.

The materials are whatever I could find in my workshop, so there is an eclectic mixture of Australian hardwoods, plywood, and pine.   The panels were all CNC milled, and the chimneys and domes were CNC turned.

It has been a fun project.  I will post a photo when they are coloured.

Horizontal Mill Engine (HME)

The HME is our Model Engineering Club competition build for 2017.  I finished making the components and tried to get it running, unsuccesfully.

So today I took it to the GSMEE morning meeting, and Rudi, who is a retired marine engineer, and has completed his own HME, took one look at mine and said that the timing was totally up the creek.

Rudi fiddled for a few minutes, and said, “it will work now”.  A couple of other members doubted his assessment, but were not confident enough to put money on it.

Anyway, this afternoon I hooked it up to a small compressor (my air brush compressor actually), and at 10psi it started to move.  At 16psi it was ticking over quite nicely.  Then the big test, throwing it into reverse.  And hallelujah!  It reversed.

Seeing an engine working, which you have made yourself, is an immensely satisfying moment.

This one still has some finishing jobs to be completed.  Like sealing the joins against steam leaks.  And a bit more polishing.   And maybe a name plate.   And there is an annoying knock which might disappear on steam.  But if not, I might need to re-make one of the bearings.

But it goes!!   Yay!!

 

A Base for the triple, and some oil holes…

Thinking about the options for a base for the triple expansion marine steam engine..

I looked at every photo I could find on the net, and thinking about whether I want to be historically accurate, or just really solid, or a bit interesting with an historical flavour.

At this stage, the decision is not set in concrete, but I am going with the last option.  Photos later in this post.

But first, I have pulled all of the major components apart, and I am spending time doing a few of those jobs which I had been avoiding because they are difficult and imprecise, and if they go badly it will be a major disaster at this stage.  Like drilling the oil holes and wells for the big ends.

Nothing precise about this.  The con rods and big end shells and bearings have been painstakingly machined, and I do not want to think about remaking them if I stuff up.  And drilling into curved surfaces, with a 1.5mm drill bit…

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That thread is 3mm dia.  The hole above the nut is the oil way, 1.5mm dia.  Very tricky and too anxiety provoking to be thinking about a video.   Amazingly, it all went well!   I now have 2 oil holes for each of the 3 big ends.  I will need to fill the well with oil with a medical syringe and fine needle, but.

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The crankshaft, turned from stainless steel a year or two ago, and the conrods.  The big ends now with lubrication points.

And here are the major engine components, after partial disassembly.

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At top left is the condensor, then the cylinder block in 2 parts, then the steam supply valve.  The square section tube is going to become the base.  And so on.  You get the picture.  I will count the bits at some stage.

Then I cut and drilled the square section aluminium tube for the base.

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The cast base of the triple, with main bearing studs and column studs in place.  All sitting on the square section alu.  Have not decided whether to bolt it together, or just Loctite it. 

Those holes in the square section were drilled and chamfered on the CNC mill.

 

Project in the Wings.

While finishing the triple expansion steam engine, I have decided on my next project.  Actually, based on my past history of procrastination with the triple, I might even put aside the triple to start on this one.

Reading this article in “Model Engineers’ Workshop” gave me the inspiration to convert a rotary table to electronic control.

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Dec 2016 MEW article

So I have commenced accumulating the bits and pieces…

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An 8″ Vertex rotary table.  I have had this for years, but unused since acquiring a universal dividing head.  Should be ideal for this project.

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A Nema 24 Stepper motor, shafts at each end, so I can use the table manually as well as electronically.  The Microstep driver was supplied packaged with the motor as a kit.  $90AUD inc postage.

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From the same supplier, a 48volt power supply.  $38AUD

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The brain of the system.  A programable microcontroller “Arduino Uno”.  I bought 5 of these for $20AUD post included.

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And an easily attachable display.  To attach the Arduino.  $19AUD

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And since I knew nothing about Arduinos, a “Getting Started” book.  Excellent.  On loan from a friend (thanks Stuart)

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And to practice some circuits and get some idea about the Arduino programming, a starter kit of bits and pieces.    $75AUD, but has been very instructive and loads of fun.   The program to run the Arduino is downloadable free from the Internet, so this kit might be a bit superfluous.

And some items of kit.  Each under $20AUD.

magnifiers

A magnifier soldering station, and head light and magnifier

multimeter

A very cheap multimeter.  Previous purchase.  Works fine.  $10AUD

I have disassembled the rotary table, and ordered a 12/8mm coupler.  I am waiting for the coupler before I start designing and cutting the main part to be fabricated which is the piece which joins the stepper and the table.

Also ordered a box to contain the electronics and switches.  Havn’t yet thought about cables,  joiners etc.

 

 

 

Edwards Pump for the Triple Expansion Steam Engine

The triple expansion steam engine has been progressing, again.  I started this project over 2 years ago, but I have taken many breaks, some prolongued.  One break lasted over 6 months while I made some cannons.

I cannot remember when I made the Edwards pump for the triple, but it must be over a year ago.   In the past few days I have returned to it, finalising the mounting to the engine, and joining the driving levers to the pump and the engine.

The Edwards pump creates the vacuum in the condenser chest.  It is an air pump.

Attached to the Edwards pump are 2 water pumps, which return condensed steam as water, to the boiler.  At least that is what I understand from the descriptions.  It feels a bit odd, making these components before understanding what they really do.

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The Edwards pump is the central cylinder and rod.  The water pumps, bolted to the sides, are just lumps of semi machined cast gunmetal at the stage this photo was taken.

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The step before the above picture, where the base of one water pump is machined.

 

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The Edwards pump, and the 2 water pumps, almost finished, attached to the engine.

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There is no clearance between the pump gland and the condensor, so the intitial hexagonal glands which I made (not shown) were unuseable.  So I made these cylindrical glands which required a tiny hook  spanner to tighten.  The hook spanner was made on the CNC mill from 1/8″ brass plate.  A little filing was required to shape the hooked tooth.  Works nicely.

 

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The pump unit, lower left, attached to the engine.  Actuating levers driven off the low pressure cylinder (not yet connected).

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The pump unit viewed from the side.

So I am at the stage where I would like this project to be finished, so I can get on with other projects.  It feels like it is close because there are very few castings remaining in the box.  But I know that the entire engine has to be disassembled, and painstakingly reassembled, freeing up some of the tight parts so it will turn over more easily.  Then the steam pipe hookups and valve timing.  Then hopefully, a video of it running!

Swap Meet Bargains

Yesterday I travelled to Ballarat, (Victoria, Australia) to a swap meet which was held on 22 acres at the airfield.

Most of the stuff in the thousands of sites, was junk from shed and farm cleanouts.  However, despite rapidly walking up and down the rows, I did not quite cover all of the sites.  My Apple watch indicated that I had walked 18km (11.2 miles) and much of that was carrying a backpack full of bought items, so it was no wonder that my ankles were aching at the end of it.

I was really only interested in the few sites which had tools from factory closures.  But my eye was drawn to the very old Caterpillar crawler tractor, a 2 tonner, not too derelict except for a broken exhaust manifold and some rusted growsers.  $AUD9500, so I kept on walking.   Lots of elderly, old and antique cars, motor bikes, and vehicular bits and pieces.

The following photos show most of the stuff which I bought, and some prices (except for the ones which SWMBO must never discover).

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A Japanese woodworker’s chisel.  9 mm wide.  Razer sharp, oak handle.  I buy one of these at each Ballarat swap meet from the same seller, a lovely Japanese woodworker who lives and works in Victoria.  These chisels are a pleasure to use.  $AUD25

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This was a bargain.  A set of good quality English BA open ender spanners, probably unused, for $AUD8

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I dont know what this is called, but it has an INT40 taper, and bolts to the workbench or mill for inserting and removing cutters from the toolholholder, and avoiding the cutter dropping down and being damaged.  Is it a tool setter?  Anyway, $AUD40

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Used but sharp, quality brands.  Carbide ball nose end mill, countersink bit, T slot cutter, and 1/4″ BSP spiral tap. $AUD30

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A new, interesting woodworking cutter, carbide, with left and right hand spirals to avoid surface furring.  $AUD10

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3 Mitutoyo telescoping gauges.  $AUD10

I mulled over a Mitutoyo 1000mm vernier caliper in perfect condition for $AUD300, but decided that it was a wanted rather than needed item, and walked on.

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A box of 12 brand new quality Wiltshire triangular files. $AUD12

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2 very nice Moore and Wright thread gauges, which have BA and Acme threads as well as metric and Imperial angles.  $AUD6

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A box of metric counterbores.  Not cheap, but good price considering the German quality, and condition.  $AUD55

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Small die holder, Sidchrome 10mm spanner, tiny Dowidatadjuster and new box of inserts.  All useful.  About $AUD45

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Chesterman vernier height gauge.  Unusual triangular column. Beautiful condition, complete range of accessories, in a lined box.  Metric and Imperial.  Price not to be dislosed to SWMBO.

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These are brass wick type oilers which I will give to the local Vintage Machinery Society.  No markings.

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My brother was a navigator in the Australian Air Force many years ago, before the age of satellite navigation.  He would sight the stars using a sextant something like this to calculate the plane’s position, while standing in a glass dome in the roof of the aircraft.  (I think that I got that description approximately correct).   He once told me that he would like to have a sextant again, so when I spotted this at the swap meet, and the price was OK, I decided to get it for him.  Maybe it will make up for all of those forgotten birthdays.  So little brother, leave some room in your suitcase when you next visit.  I will leave the clean up and renovation to you.

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Elliott Bros London.

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It looks fairly complete and intact.  Of course I have no idea how it works.

Model Ottoman Bombard – Painting

I would have preferred that the title of this blog was “Finishing the Ottoman Bombard”, but I am still waiting for the vectors of the barrel mouth decorations and Arabic (?) writing, and the touch hole.

But I have at least painted the bombard, and the pictures follow.  You will notice that I have not attempted to reproduce the bronze or copper colours of the orginal in Fort Nelson.  Partly because I doubted my ability to make painting such variegated patterns realistic, and partly because the cannon would not have looked like that in its heyday of 1464.  It would probably have been either black, like most SBML cannons (smooth bore muzzle loading), or possibly gaudy golds and reds and blues like other medieval items.  So I painted it black.  I like it.  If I get evidence that it should be more colourful I can change it later.

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First coat – Primer.  Hmmm… interesting colour.

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Next coat – matt black brushed on, to fill the hairline wood cracks.  Incidentally, the (dirty) parquetry floor is also made from the red gum house stumps from which the cannon is made.

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final two coats –  matt black, from a spray can. 

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So there it is, finished except for the barrel mouth engraving, and the touch hole.  Now what to do with it…   SWMBO says it might be useful as an umbrella stand.

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The breech.  25mm diameter explosion chamber.  1:10 scale

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The barrel, 63mm bore.

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Assembled.  The model is 520mm long.

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It does need some decoration

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Modelling A Turkish Bombard- The Pins

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There are 16 pins at each end of each section of the cannon.

These were certainly used as leverage points, for very strong men with large levers to rotate the 8-9  tonne segments against each other to engage and tighten the screw.

I cannot see how the pins would have been cast with the breech and barrel.  For my model I decided to make separate pins and fit them into the gap between the big rings, then insert a grub screw through both rings and the pin.  The holes are then filled.

I wonder if a similar method was used in 1464.  I would love to have a close look at the original cannon to figure this out.  From the photographs, I can see no evidence of later insertion of pins, but neither can I see how it would have been done any other way.

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Drilling the holes for the grub screws

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In order to continue with red gum, I made my own pins.  This is the setup.  The blank is held approximately centre in a 4 jaw….

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…and the pins are turned, centre drilled, drilled, cut to length,  and tapped M4.  64 altogether.

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The M4 x 25mm grubscrew is screwed into the pin.  The wood join is super glued.  Also, I am attempting to patch the worst of the thread tearouts.

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Using a battery screwdriver to insert the grub screws.  The pins protrude above the ring surface for a reason..

 

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Sanding the pins flush with the rings.  Check the photo of the original 1464 model.  There is also some wood filler in other splits.  Not surprising after holding up a house for 70 years.

The holes are now filled with wood filler, and will be sanded flush.  They should be invisible after painting.

Next the painting, the stands, and some cannon balls.  How to reproduce that aged copper colour…

 

Turkish Bombard 1:10 scale

Just for fun I will use my newly converted CNC lathe to make a 1:10 bombard.  The original was cast in 1464 and was thought to be a close copy of the bombards which Mehmet 2 (“the conqueror”) used to breach the walls of Constantinople in 1453.  There are several of these bombards still in existence, including one in UK, which was given to Queen Victoria by the then Turkish Sultan.

These bombards were last used, against the British, in 1807, when a British warship was holed with substantial loss of life.  Pretty amazing for a 340 year old weapon.

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5.2 meters long, 1.060 meter diameter. 16.8 tonnes.

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The large thread connected the halves.  Easier transportation, and casting.

 

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Is this Turkish or Arabic?

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Granite balls are 630mm diameter.

 

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A reconstruction of the walls of Constantinople, with moat.  Almost 1000 years old in 1453  

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And as they are today.  Massive.  High.

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Huge siege cannon used in the final assault and fall of Constantinople in 1453. Diorama in Askeri Museum, Istanbul, Turkey.  The bombards were probably dug in, to manage the massive recoil, and concentrate the aim at a particular wall section.  There is a wooden structure built around the cannon in the background of this modern picture.  As far as I know there are no surviving  wooden structures like this.  Nor have I come across any old pictures, but if anyone knows of any I would be very interested.  The bombards took about 3 hours to cool, cleanout and reload.  

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My model will be about 520mm long.  I would like to make it from bronze, or gunmetal as in the original.  Any mistakes will be costly.

So I have decided to make a prototype in wood.  That will test my drawing, the machining procedure, and the final appearance.  Not to mention how the CNC lathe will handle the task.

I will use a very dense, tight grained Australian hardwood (red gum).  The wood was salvaged when my house stumps were replaced with concrete.  Some was used to make parquetry, and the rest was put aside for possible future use.  Such as this.

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About to cut off the below ground section of a 70 year old house stump.

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A 5hp metal lathe with a tungsten bit chomps through the hard dry wood.

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I turned 6 lengths before I found 2 that were satisfactory.  The rest had sap holes or splits.

I have used Ezilathe to generate the G codes.

to be continued….

 

CNC Lathe Conversion- final

Before I am hung, drawn and quartered, for operating a lathe without guards, here is the proof that I have been sensible.

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Guard over the X axis pulleys.  I like to watch the wheels going round and round, hence the transparent top.   Also note the cover over the exposed ball screw.

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Cover over the Z axis pulleys and belt, again transparent.  If I wore a watch it would be transparent.

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I also installed an ER40 collet chuck.   I will be using this for all work with diameters under 26mm.

CNC Lathe Conversion – 17

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.

Steam Engine Oilers

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.

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Just needs 1/4″ BSPT fittings and and oil wick tube so they can be fitted to the engine.

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The copper tube silver soldered to the brass cylinders (top), the brass blanks for the lids (bottom) and the mandrel to hold the assembly (bottom centre) during CNC turning and drilling.

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The mandrel to hold the body (left) and the mandrel for the lid (right).  The cap screw head and hole in the mandrel have a 2 degree taper.  The slits were cut with a 1mm thick friction blade.

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Rough turning the base.

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Turning the lid.  The mandrel is held in an ER32 collet chuck

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Engraving the lid.  Using a mister for cooling and lubrication.  16000rpm, 200mm/min, 90 degree TC engraving cutter.

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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.

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The 1865 Wedlake and Dendy

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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.

http://www.marinersmuseum.org/blog/2010/04/one-oil-cup-down/

(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.)

OK, so guess the purpose

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A pair of sheet metal pliers, to which I welded a steel tab.   Why?

For the answer click on the link.

For some reason the auto link is not working.  You will have to type the link manually.

Later update…   I dont get this.  Even the manually typed link to the explanation does not appear.

OK.   The explanation is that these sheet metal pliers have been converted into canvas stretching pliers for my daughter who likes to make her own canvases for oil painting.  Youtube sucks sometimes.

Try searching “Thomas Baker’s canvas stretching tutorial” to see how the pliers are used.

 

 

 

 

 

 

MORE ANCIENT GREEK TECHNOLOGY, THE ANTIKYTHERA MECHANISM

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.

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Not much at first glance, but when it was examined with modern scanning and X ray techniques…

Look it up on Wikipedia..

https://en.wikipedia.org/wiki/Antikythera_mechanism

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.

ANCIENT GREEK MACHINING

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.

  1. The gold death mask of Agamemnon (probably not Agamemnon’s but that is another story).
  2. The Antikythera machine.   More about that in a future post.
  3. A gynaecological speculum.

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).

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Not a great photo, through a glass cover, and ISO cranked up to several thousand.

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.

 

 

CNC Lathe conversion -16

The wiring of the lathe is complete.  (Except for limit switches.  They can be added at any time).

Mach 3 is configured.  The wireless hand control is installed and working.  Ezilathe installed and waiting for input.

Some covers to be made.

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Hook ups in progress.  That’s the faulty VSD on top of the electronics enclosure.  The CNC engineer lost his hair trying to figure out the problem.

Still some testing and fine tuning required.

But nothing much will happen in the workshop for the next  3 weeks.

 

 

CNC lathe conversion -14

These lathe CNC conversion posts are probably becoming a bit tiresome, but just in case there is someone out there who is interested, I will continue until the job is finished.

The latest was to make and install a spindle speed (and position – thanks David M) sensor.  It consists of a disk with a slot cut in the periphery, attached to the main spindle.  And an opto-electronic sensor which is connected to its own electronic board, thence to the breakout board and VSD.

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The disc with the slot at 8:30 and the sensor at 9:00.  I must have chosen the wrong cutter or turning speed for that disc aluminium…  looks a bit rough.  (note added 13/7    Stuart T says that I should have used coolant-lubricant).

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View from above.  Any clearer?   That gear is now superfluous except as a spacer.

So there is one electronic impulse per spindle revolution.  That is enough to measure the RPM’s.   Essential for cutting threads.

The beauty of this system is that there is no gear selection or changing, and ANY thread pitch can be selected…  metric, imperial, BA  etc…  any odd ball thread that your heart desires.

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cnc lathe - 3

The HTD (high torque drive, I am informed by many readers) pulleys and belts and taper lock fittings.  Unfortunately I could not find a taper lock to fit the small pulleys, so when it is all finally, definitely, absolutely, correctly,  positioned, I will Loctite them in position.  Protective covers yet to be made.  I quite like to see the mechanicals in action, so I am intending to make the covers from clear polycarbonate.(Lexan) .

CNC Lathe conversion -13

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Adjusting the lead screw.

The 48 tooth HTD pulley has been installed using a taper lock.

Then some time was spent adjusting the parallelism of the lead screw.  That requires quite a few movements of the carriage along the 600mm thread.  Each 360 degree turn of the lead screw advances the carriage 6mm, so you can understand that I became a bit impatient with all of the repetitive hand actions to move the carriage from one end to the other.

So this was a solution to that issue.  That HTD belt is the one that was too long, so I was happy to find a use for it.    The variable speed battery drill shot the carriage end to end in a couple of seconds.

All is now adjusted parallel.

A few more little installation issues, then for the wiring.

CNC Lathe conversion -12

Today I fitted the lead screw.

No big deal, I sense that you are thinking.  After all, the ends are machined, the bearings fitted, and all waits in readiness.

True, but there is a strict sequence of events.  And since it has been 3 or more weeks since it has been together, I had to rediscover the sequence, by trial and error.  And each bit of the fitting is very heavy, very delicate, very tricky.  So it took me several hours to get to the  final photo in this blog.

But first a view of the inside of the newly machined apron.

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The lead screw fitted.  The cross slide screw is also fitted.  Note the red E Stop panic button fitted to the left.    Next job is to fit a support bearing at the right hand end of the screw.  Then to check and adjust parallelism of the screws.  A rough check showed that they are within 0.25mm

CNC Lathe conversion – 9

The CNC lathe conversion has been happening, despite no posts on the blog.

I have mounted the electronics enclosure, and mounted the various components inside.  No wiring yet.

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This stainless steel tool box is the electronics enclosure.  It fits the space quite nicely, and is adequately big.  The back gear cover to the right will be retained, although the back gears have been discarded.  The main switch and emergency stop will be mounted somewhere on this cover.

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The Variable speed drive (VSD) sits on top.  That will control the spindle speed.  The transformers, stepper motor drives, and Breakout board (the heart of the system) are positioned inside.  Plus cooling fan and filters.  Ready for wiring.

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Drilling the apron to attach the cross slide ball screw bearing.  One chance only at this one, so the setting up took a couple of hours.  The apron is clamped to a large angle bracket on the milling table.   M6 threading followed.

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The end result.  The bearing as attached to the apron and the ball screw is in place.  I machined the end of this ball screw to fit the bearing, cut a thread (M10x1), and machined the end to accept the pulley.  All good.  There is 0.25mm adjustment available if required, but it all seems pretty correct.  The bearing sits on a carefully machined block which is 7.85mm thick.   Still waiting the lead screw machining.(!!)

NOT MUCH GOING ON TODAY

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This is my workbench after I had almost finished tidying it.  Really.  

 

Then I thought about machining the ends of the cross slide ball screw.

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So I mounted the collet chuck and checked the runout.   0 to o.01mm.  Then I did a test cut in the ball screw.   Hard hard hard.  But it did cut.  Then I chickened out and decided to finish it another day.

So, looking around the workshop for something else to do, I decided to pretty up the new CNC lathe apron.

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Before (milled surface).

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During

 

And I forgot to take a photo of the after, but it did look nice and smooth and shiny (look at the mirror finish behind the wheel).

Being retired is great!

CNC Lathe Conversion – 8

Continuing the installation of the ball screws, and stepper motors.

I have completely removed the digital read out module and glass slides, and they will not be reinstalled.  Not sure what I will do with them.   They are only a year or two old, and in good condition.  I will probably put them on Ebay.  Same with the old gearbox, carriage apron, and electric controls.

Here are some pics of the plates and blocks which support the ball screws and steppers.

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This is the steel plate at the headstock end, bolted to the bed.  And the block with the holes is cast iron 42mm thick, to support the leadscrew and leadscrew stepper motor.  It was machined out of an old piece of machinery, hence some unintended holes.   Being cast iron it was fairly easy to machine, but incredibly dirty. Turned everything in the workshop black, including me.  (whoops.   Unintended not PC)

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This is the block which replaces the gears and controls of the apron under the carriage.  The thick block is cast iron, and the stepper motor support is 20mm thick steel.  Very heavy.

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This plate is hidden under the carriage.  It secures the lead screw nut.

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The slot in the carriage had to be widened and deepened a bit, in order to accomodate the slightly fatter and taller cross slide nut.  See the next photo to see the setup for milling the hole through the carriage.

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A rather confusing photo.  The carriage is clamped to a large angle plate on the mill, and I am enlarging the hole which accommodates the cross slide ball screw.  It was at the limit of what my mill could manage.  An intermittent cut, with a lot of tool stick out.   Not the best way of doing the job, but it worked OK.

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Plastic covers attached to the stepper motors, and toothed belt pulleys fitted.

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Checking the centres between the pulleys, using 2 wooden wedges to push the pulleys apart.

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The underside of the carriage.  The hole and channel at the left side of the picture was machined to accept the larger cross slide screw

So you can see that I have been busy since the last post.

At present the lead screw is at Linear Bearings in Melbourne, having the ends machined to accept the driving pulley, and support bearings.  I did consider doing this machining myself, but decided to leave it to the professionals because of the high cost of the item and the hardness of the material.

CNC Lathe conversion-7

I am still waiting for the replacement ball nut for the lathe cross slide to arrive.

Meanwhile, I have been busy machining the supports for the lead screw.

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Drilling the holes for the support bolts for the lead screw nut

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And gradually drilling the hole to 49mm!

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That is a 49mm drill!  First time that I have used it!  Thank goodness for the  FS Wizard app, to give me some idea about feeds and speeds.  Following this I used a boring head to enlarge the hole to 55mm.

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Gradually enlarged the hole in 20mm steel to 55mm diameter.  and here is the lead ball screw, sitting roughly in its proper position.

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So this is where I am at.  The lead ball screw is sitting approximately in its correct position.  Considerable adjustment required.  And I am yet to turn the ball screw ends to their correct dimensions.

CNC lathe conversion-6. EBay problem

My first hitch occurred today.

I was very excited to receive the nut for the cross slide ball screw.  If you have been following these posts you might recall that the ground ball screw for the cross slide came from Taiwan, and arrived in 3 days.  But I had to order the nut from a seller in USA.  The nut was advertised as new old stock, but with no packaging.  That was OK, but the postage cost for such a tiny item was ferocious.

It was the last item to arrive from overseas.   However when I looked at it, it was obviously NOT new.

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The cap screws holding the ball recirculating tube were different from each other, and the washers underneath were too big for the screws.  Obviously not the way that TNK made it.  Somebody has had the nut apart.  And the ball retaining tube was very scratched  and loose.  Again, not TNK standard.

But no biggie.  If it works — fine.

So I turned up a retaining tube to remove the previous nut from the ballscrew, and it came off without any drama.

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But when I tried to fit the “new” nut, it just would not go on.  Tried reversing the direction.  No go.  Bugger bugger.

Somebody has altered or changed the “new” nut.  Maybe installed balls which are too big, or maybe damaged the entry thread.  I do not know.

What to do.  I have been waiting 2 weeks for this to arrive.

First, Ebay email to the seller.  See what the response is.  Ask for a refund.  The postage was almost as expensive as the nut. If unsatisfactory response, they will get the worst Ebay feedback ever.

There is one other seller of these nuts on Ebay, also in USA, and 50% more expensive, and the postage is also 50% more expensive. (how DOES ebay come up with the postage charges.  It seems more related to the cost of the item rather than the weight-size etc.)  But the nuts are in original packaging.  And I want to get going with this, so fuck it.  Pay up and get it.

I will report in a later post.  (if the bad language in this post seems to reflect my state of mind, well, yes it does.)

 

PS.  Next day.  After sending photos of the issue, the seller accepted responsibility, and I am getting a full refund.  That restores my faith in Ebay/Paypal.   I hope that the next one is in better condition, and comes a bit more quickly.  Sorry for the bad language.

CNC Lathe conversion -5

This is a list of the components which I have accumulated to convert a manual lathe to a CNC lathe.  It is not quite complete, but close.

  1.  Lead ball screw and cross slide ball screw.  Both with nuts and end bearings.  (no pic yet)
  2. The electronic components.
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The electronic components, not including computer and parallel cable and manual pulse generator.

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Two stepper motors.  Nema 34, 1200 inch – oz.  With rear covers.

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A Gecko microstep drive for each stepper motor

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Cable and connectors for the stepper motors

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A transformer-power supply (48 volt)

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Another transformer-power supply (5 volt).

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3 phase 1.5kw motor (top) to replace the single phase motor (bottom)

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Timing belt gears 24 and 48 tooth, 5M.  Order belts when size is definitely established.

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FK20 lead screw bearing and Ball screw covers

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The electronic heart of the system- the breakout board.  A C11R9

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The index pulse board and sensor.  A C3.

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Manual pulse generator, wireless.

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Variable speed drive, identical to this one on the mill

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An electrical enclosure, to hold the various components.  This stainless steel box was originally an item of medical kit.  Here I am checking out one possible location.  Not yet definitely decided to use this.

Finally in the electronics section, I will need a computer, loaded with Mach3 and Ezilathe.  Surprisingly, it does not need to be a particularly powerful PC.  And there are advantages in using an older operating system such as  XPpro.  I think there are a couple of those in the attic.  If not, I should be able to pick one up for under $100.

3. Various structural items.  Most of these will be 20mm thick x 200mm wide steel, cut to size and shaped and drilled.  I will take pics of these as I make them.  I was planning to have them water jet cut, but the shapes a fairly simple so I will cut and machine them myself as I go.

So, that is most of the items for the job.  I have spent about $AUD1100 on the ball screws and nuts, about $AUD1500 on the electronics and electrics, and maybe another $AUD500 on pulleys, belts, steel, taper locks, fasteners etc. I will add it all up accurately at the completion.  The lathe was cheap, bought sight unseen a few years ago.   So all up, I should have a CNC lathe for under $AUD4000.  And many pleasant hours of design and machining.  And a great learning exercise.  Stay tuned!

CNC Lathe conversion -4

I am in the process of collecting all of the components for the conversion.  Parcels are arriving from South Korea, Taiwan, China, USA and Australia.  Next post I will take a photo of the bits, before I commence assembly.  I have spent a lot of hours on the computer drawing up the positioning of the new components, deciding which components to get, then communicating with the sellers and making the purchases.  Not to mention hanging around home when parcels are due.  If I duck out for 10 minutes, that’s when the delivery van arrives.  And of course he leaves his little card “sorry we missed you”.

This post I will show you some of the drawings of the proposed conversion.  Of course the first step is to strip the lathe of all of the old manual controls, gears, motor, Digital read out, carriage apron, lead and cross slide screw, electric control box and contents.  (taking photos of every component insitu in case of a change of mind, and restoration required later).

Then measuring the bed and carriage in minute and accurate detail, and drawing it in CAD.

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This is the lathe side on and end views, showing the new lead ball screw in red and green.  The cross slide ball screw is also there, but not well seen at this scale.  The 4 ball screws at top left are the possible combinations for eventual installation.  The second red one is the position eventually decided.  The green ones are with the nut re-installed in reverse direction.   I really did not want to remove and re-install the nut, because it is pre-loaded, and I do not want to risk disturbing the setup.

Many drawing versions are required, and as the components arrive, I find myself making changes.  This is definitely not the final version.   The two carriages show the carriage in its extreme positions on the lathe bed.

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This was an early sketch of how I thought I would arrange the cross slide motor and lead screw nut.

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This is a fairly accurate drawing of a cross section through the cross slide.  Black is existing.  Red is the new nut and ball screw.  You can see that removal of some of the cross slide bed iron will be required.  After looking at this I decided to move the nut and screw up a couple of millimeters.

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The Internet has been very useful in showing what fittings are available.  These are a few of the catalogues and tables which I have downloaded.  Some sites even provide CAD drawings so their components can be inserted into my CAD drawing to see if they will work together.

THROAT CUTTER WALL SMASHER

Some pics which we snapped a few years ago of a large bombard, sitting outside the wall of the “Throatcutter” castle (RumeliHisari), a few miles from Istanbul-Constantinople, overlooking the Bosphorus.  This castle was built by the Turks in order to control the Bosphorus waterway, just before they besieged Constantinople in 1453.

The cannon was clearly placed in this current position just for display.

Could this have been the one which breached the Theodosian walls in 1453?  It seems to be an  appropriate size and style.

 

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That’s a younger me.  No name plate  about the cannon.

 

 

 

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The bore is about 600mm.  The narrow part near the breach is the powder explosion chamber, with an enormously thick wall.  The original cannon was recorded as requiring 60 oxen and 400 men to drag it from its casting place.  And a gun crew of 200 men.  Cast in one piece.  (later note:  not sure about cast in one piece.  I will be in Istanbul soon.  I will try to determine construction.)

This could well be the original Orban cannon.

Updated Notes :

The Orban cannon was recorded 8.2 metres (27 feet) long, so the one in the photos cannot be it, unless the recorded figures are exaggerated.  Orban did cast additional smaller cannons for Mehmet 2 for the seige.

The biggest Orban cannon at the seige was named “Basilica”.  It fired  stone balls weighing 272kg (600lbs) over 1.6km (1 mile).   Reload took 3 hours.  The stone balls were in short supply.  Not surprising, considering the labour which must have been involved in making them.

Orban is thought to have been Hungarian or possibly German.

 

COMPRESSED AIR ON THE CNC MILL

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.

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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.

Recommended.

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.

Lathe conversion to CNC -3 Ball Screws

I have learnt a lot about ball screws in the past few days.  And I have purchased 2 ball screws and nuts on Ebay.  For those relatives and friends who follow this post, who have no idea what I am talking about, the “ballscrews” are what determines where the cutting tool on the lathe is positioned.  Very crucial.  (can something be “very” crucial?  It looks a bit like “very unique”. )

1

Ball screws are the usual positioning screws  for CNC machines these days.  The alternative is Acme or square thread screws, but the few manufacturers who used to use these have all switched to ball screws (as far as I know).  Even Wabeco, the respected German lathe manufacturer no longer specifies any threads except ball screws.

Ball screws require less power to turn due to friction being a fraction of the alternatives.  Ball screws are silent.  If they are noisy there is something wrong.  They are generally more accurate than square or Acme threads.  They used to be many times more expensive than the older types, but since China/Taiwan has taken over most of the manufacturing, often using equipment sourced from US/Europe/Japan, the costs have plummeted.

And the backlash is minimal or zero.   Another name for ballscrews is “antibacklash screws”.

Backlash is annoying on a manual lathe, but it is very important on the cross slide of a CNC lathe.  Interestingly, it is less important on the CNC lathe lead screw, because most CNC lathe machining  on the leadscrew occurs in one direction only, towards the headstock.  However,  the cross slide is machining in both directions, in and out,  so the absence of backlash is necessary to maintain workpiece accuracy.

Ballscrews have grades of accuracy varying from C0 -C20.  The bigger the number, the less accurate the screw.   In general, it is recommended that industrial lathes should be C3-C5,  which means zero backlash, and accuracy of about 0.001mm.  That degree of accuracy is quite expensive, costing thousands of dollars per screw, and only attainable in ball screws which have been finished with precision grinding.  The alternative is ball screws which have been “rolled”.  These are much less expensive, costing hundreds of dollars per screw, depending on the degree of accuracy.  The best rolled screws can attain an accuracy of 0.01-0.02mm (C7), down to 0.1mm (C20).  These are approximate figures which I have gleaned from several manufacturers’ specifications.

So from scale drawings of the lathe bed and carriage and cross slide, I worked out that I needed the following…

 

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This is a photo of a ball nut and screw very similar to what I have bought for the cross slide.  THK brand, 14mm diameter screw, 4mm pitch, and BNT nut style.  Note the rounded channels that the balls occupy.

 

  1. Cross slide screw 14mm diameter, 400mm long with at least 200mm of thread, and a thread pitch of no more than 5mm.  The cross slide nut needed to be a THK BNT pattern in order to fit into the cross slide with a minimum of space making machining.  THK is a large manufacturer, with intermediate prices, and a very good reputation.  The screw needs to be a specific length, and one end needs to be machined to go through a bearing/ bearing housing and have a tooth belt pulley attached.  I contacted a ball screw supplier, to enquire about ground ball screws, but discovered that these were rarely specified due to their cost, and delay of 3-6 months.  A C7 rolled screw with the BNT nut was going to cost about $AUD400-450.  So I searched Ebay Australia, Ebay USA, and Ebay UK.  Eventually, I found and bought a used ground screw with end bearings and housings from Taiwan for $AUD250.  The nut was the wrong type, but I found a new correct style nut on Ebay USA for $AUD100.  I know that sounds like I have not saved much money, but that gives me a super-accurate ground ball screw!  Of the correct size and type.  I am keeping my fingers crossed that the pieces sourced from different countries will go together.  Theoretically, they should.  (same manufacturer, same size, “ground” specification, etc etc.  but finger tightly crossed).
  2. The lead screw approximately 1000-1100mm long, 25-32mm diameter, and 5-6mm lead.  Super accuracy not required in the lead screw, and I could have bought a new rolled one from China for about $AUD300-400.  But then I spotted one in South Korea, new old stock, 28mm diameter, 6mm lead, with unmachined ends.  THK brand.   Asking price just within budget.    And this was a C5, ground screw, possibly more accurate than I expected for the price, and unused, but hey, it sounded like a bargain.   So I offered about 15% less and was somewhat surprised to have the offer accepted.   So that one is arriving in a week or two.  Then to buy mounts and arrange end machining of the screw.  Although not crucial it will have zero backlash, due to the C5 designation, and the fact that it has two ballnuts bolted together in a “pre-loaded” fashion.  I expect that it will be the most accurate component on the lathe!  No decent photo to post.

(ps.  see the comments section for discussion about axial accuracy and backlash.  A super accurate C5 ballscrew has axial play (backlash) specification of 0.020mm, but the double ballnut configuration will reduce that number substantially.  “zero backlash” apparently does not really mean zero.)

 

 

 

 

Lathe Conversion to CNC -2 and Wall Smashers

After removing most of the lathe gear which will not be required after the CNC conversion, the lathe is looking a bit naked.

The carriage apron, the lead screw, the back gears, the drive rod and control rods have all been removed.  Also the cross slide screw and handle.  The cross slide itself is temporarily removed, but available for measuring for fitting a ball screw.

I have now made accurate measurements and drawings of the lathe bed and carriage, in order to choose ball screws and nuts for the lead screw and cross slide.

The lead ball screw is easy.  There is plenty of room and machined surfaces for attachment.  I see no particular problems there.  Just time, careful machining and expense.  Chinese or Euro-American?  As usual, there is a big price difference and maybe not such a big quality difference as previously.   Looking at 25 or 32mm diameter, with 550-600mm of thread.

The cross slide ball screw is another matter.  The current cross slide square thread screw is 14mm diameter, and I would like to use a ball screw about the same size.  The problem is that a ball screw nut is considerably bulkier than the existing square thread nut, so some machining of the cross slide will be required to make space.  The cross slide dimensions are already fairly tight, to maximise the swing over the carriage.  I do not want to weaken the cross slide too much.  So it is all a bit tricky.  Time to consider options. And to get another opinion.

No lathe pics, so here are some of Turkish wall smashers.

 

Turkish cannon

This one was given to Queen Victoria by the Turkish sultan.  It was made about a decade after the fall of Constantinople.  It was cast in 2 halves.  There is a giant thread connecting the halves.  I imagine that the strange square holes are to allow levers to be inserted for the screwing by many strong men.  No double entendre  intended.

 

Turkish wall smasher

 

 

Turkish cannon and ball

This one could have been used to make the breach in the wall at the fall of Constantinople 1453.  That stone ball is 600mm diameter.  With no trunnions or other supporting mechanism the barrel was probably dug into the ground for support.  That would allow repeated shots at exactly the same point in the walls.  8-11 shots per day.  It was made for the invading Turks by Orban, a christian who had previously offered his services to the defending Byzantines.  The Byzantines whose empire by this time had been reduced to a tiny fraction plus the city itself, could not afford his services.  The rest is history.

 

 

 

 

 

Lathe conversion to CNC

The carronade is finished, as far as I intend to take it.  At some future date I might make pulleys and ropes etc, but at this stage I am putting it on the mantlepiece.  (mantelpiece groans).   Some detailed pics in a future post.

I have commenced my next project.

I have a CNC lathe but it will accept work up to only 125mm diameter and 125mm long.  It was not big enough for the long gun, and barely fitted the carronade.   And I have some ideas of further larger projects (field artillery pieces, and possibly a model of a Turkish wall smasher like the ones which allow the Turks to conquer Constantinople.  That one was almost 6 meters long, and fired stone balls of 600mm diameter!!!   So even at 1:10 I need a bigger lathe.

OK, so I could use a manual lathe, but that is not the point.  A bigger CNC lathe would be fun.  And I have a Taiwanese one which I think would be suitable for conversion.  It is 600mm between centres, (just big enough for my Turkish smasher), and about 300mm swing.  It is not pleasant to use as a manual lathe due to very noisy spur gears.  So I have decided to convert it to CNC.

The steps are:

  1.  Remove the existing lead screw, cross slide screw, apron, back gears, gear box and more.
  2. Measure for ball screws and buy them.
  3. Buy the electronics.   Stepper motors (7amp NEMA34), break out board, Gecko stepper drivers, limit switches, power supply, 3 phase 2hp spindle motor, etc etc
  4. Fit the ball screws and motors.
  5. Fit the electronic components and hook them up (Stuart, I hope that you are reading this)
  6. Configure Mach3 and Ezylathe on an old computer
  7. Make a Turkish smasher

I have made a start.  Removed most of the unwanted manual components from the lathe today.  It felt very threatening and unnatural to be wrecking a perfectly good lathe.  See the photos.  At this stage I am taking lots of photos in case I have a change of heart and restore it to its original state.  But I will press on.  Watch this blog.  I expect that the conversion will take a couple of months, by the time components arrive from overseas.

 

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The lathe prior to CNC conversion

 

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After removing the lead screw, apron, gear box, cross slide back gears etc etc.  Looks a bit naked.  Not much remaining.

 

 

CANNON BALLS FLOAT IN THIS LIQUID

OK,  so I am not quite ready to post my pics of the scale model carronade, and the number of hits and likes on this site is plummeting, so I am re-posting someone else’s video to retain your interest.  This is interesting!

 

Mercury has a melting point of -38 celsius, and a boiling point of 356 celsius.  It is 13.6  times as dense as water.  It is the only metal which is liquid at room temperature.

Mercury is very poisonous.  However it is a component of dental amalgam, used in tooth fillings, but it is calculated that you would need 490 fillings to reach toxic levels.  I hope so.

MACRAME FOR MACHINISTS

This video proves that you cannot fold paper more than 7 times.

It also shows what happens if you try.

It also shows what machinists with too much time on their hands get up to.

Enjoy

 

So, where is the macrame?  I sense you are asking.   Maybe I meant to title this “Origami for machinists”.   But just in case you are disappointed about the absence of macrame, I add the following…

Picture of rather attractive woman in knotted string bikini would not paste….    sorry.

 

OLDEST STEAM ENGINE- Model

Hero of Alexandria, in Roman Egypt, described a steam engine 2000 years ago.  He is credited with inventing the first steam engine, although it is very likely that he was just describing something already in existence as previously described by another Roman, Vitellius, a hundred or so years earlier.

Today I saw a working example of a Hero type engine, and it was much more impressive than I expected.  One of our club members has built 2 Hero engines, and the following video  shows one of them working.

I think that I will have to make one to show the grandchildren.

Click on the arrow to see another grossly amateurish video.

Incidentally, Emperor Nero, who hated his mother, put her in a ship which, as planned, fell apart when afloat with mummy dearest on board.  Unfortunately for Nero she could swim.  What is really interesting is that the ship is described as having some sort of mechanical propulsion system.  Maybe steam??

 

Video of Making the Model Naval Cannon

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.

German Engineering

I am waiting for the water jet cutting so I can do the machining and welding on the seismic wave generator.

In the meantime, the washing machine at home had been sounding very noisy lately.  I say that with confidence, because my hearing is so poor I am told that I need hearing aids.  And the washing machine sounded like an overloaded cement mixer, even to me.

But despite the noise, the Miele front loading machine still worked fine.  But the noise when spin drying was painful.

Our Miele machines tend to be changed at 20+ year intervals, and this one was only 15 years old.

So I did the manly thing, and got SWMBO to point out which was the dryer and which was the washing machine, and I took the washing machine apart to diagnose the problem. My prediction was that the main bearings had disintegrated, because the inner drum seemed very loose.

I undid the cabinet torx screws, carefully disconnected wires after taking photographs to record positions, separated pipes and flanges.  And asked my neighbour to help me lift out the drum.  It took two of us because it is bloody heavy.

You might be wondering at this point how a retired gynaecologist knows about washing machine repairs.

Well, the truth is, that he doesn’t.

But the internet, and particularly YouTube has information about “How To Do Anything”.  Including repairing Miele washing machines.

So here we were.  I had found the source of the noise.

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This is the main shaft and aluminium casting which holds the washing machine drum.  It has broken into 4 pieces.

How, you might ask, as I did, did that washing machine work for several months with this?

I dont know.

Must be German engineering.

 

p.s.  I rather cheekily emailed Miele Australia to enquire about about spare parts.  Within 24 hours I had a polite reply that a replacement drum with attached casting and shaft was available, at a cost of $AUD750. (!!)

In the meantime, in fact before I had even started the teardown, SWMBO had gone out and bought a replacement washing machine.  She of little faith!

So the old machine sits there in bits.  I guess that it will go to the recycler.  But I am sort of hoping that a W828 Miele washing machine will turn up on Ebay, so I can use the parts to fix mine, just to see if I can put it all together again.

 

Shear Wave Seismic Source

You are probably wondering WTF this is about.

So was I, when I was asked to consider making one.

I gather that researchers and geologists use them to work out what is going on in a geological sense underneath our feet.

Seismic waves are generated from ground level, and instruments pick up frequency changes and time delays, providing information about what is happening below.

The seismic wave generator has the following requirements…

  1. it is anchored or spiked to the ground surface

2.  the spikes must be able to penetrate all types of ground surfaces, including asphalt, and be removable from the ground, and from the device.

3. it must be transportable by hand i.e. no more than 20-25kg

4. it must withstand thousands of impacts from a sledge hammer, in 2 directions

5. it must be  durable, repairable and not too expensive

6. the user must be able to stand safely on the device, while swinging the sledge hammer

7.  it must not generate sparks in some situations

So I have been thinking about these requirements, and I have produced a plan which has been accepted by the client.

Photos of the project next post.

 

 

 

1779 Naval Cannon Scale Model

It is almost 2 months ago that I started this model.

I thought that it would take 3 or 4 days!

Anyway, here it is.

It will look interesting on the mantelpiece.

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Note the hinge and square bolts and keys on the trunnion straps.

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A good view of the elevating apparatus, the quoin.

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A trunnion, trunnion band, trunnion bolts and key.

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Powder pan and touch hole.

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The underbelly

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It goes on display at the Geelong Wooden Boats Show next weekend.

 

Cannon, final parts.

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).

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Finished rectangular hole on right.  FIling in progress on LHS.  The head of the bolt was silver soldered to the shaft.  Second soldering effort worked.

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.

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Parting the first key.

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That key is 9mm long and 6mm high.  It still needed some filing, which I accomplished in this tiny toolmakers’ Starrett vice.  That file is 3x3mm.

 

Cannon trunnion shoulders, flash pan and trunnion brackets.

Another couple of long and very enjoyable workshop days, making various bits for the 1779 24 pounder model naval cannon.

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The trunnion shoulders were bored to a close fit on the trunnions, then the barrel curve was machined on the vertical mill.

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Using a boring head to make the barrel curve.

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Testing the barrel curve.  A good fit.

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The trunnion shoulders were glued into position with Loctite.

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The trunnion bands were difficult and fiddly.  The 3 components of each were joined with silver solder, then several hours was spent with tiny  files to achieve the shape pictured.

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The square cap trunnion bolts are yet to be made.

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Milling the powder pan enclosure with a 2.3mm end mill.

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The powder pan, sculptured from bar stock.  The base gets milled away.

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The powder pan is glued into place with Loctite.

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.

Cannon Trunnions

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!

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Then I attached the knob at the breech end, M4 threaded rod attachment.

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Looks OK, Yes?  This protrusion would also have been part of the cannon casting.  It was used to attach the huge ropes which limited the recoil movement when the cannon was fired.  

 

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Turned some brass for the trunnion.  It was later cut into two pieces.

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Drilled the holes with an endmill in the barrel for the trunnions.  Stopped short of the bore by 3mm.  Jerry Howell specified threaded trunnions, but I decided to silver solder them in place.

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This is my silver soldering forge, for this project. (actually a hearth).   The barrel is still a hefty lump of brass, and I predicted that a lot of heat would be required to raise it to a suitable temperature.  The base is steel, and the bricks are fire bricks.  I used oxyacetylene as my heat source.

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After the silver soldering.  Not quite so pretty now.  I waited an hour before I could handle the hot item.  Note that the spigot in the bore which was Loctited in place, has come out.  Eventually, I became impatient, and applied wet rags to speed up the cooling process.

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Then a soak in dilute sulphuric acid for 15-30 minutes, to remove the flux.

Turning a cannon barrel

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.

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That’s me, watching carefully.  Later we installed the swarf cover.

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The metal turning lathe does not miss a beat chomping through wood.  These are the roughing cuts.  F300mm/min, S800/min.

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The Mach3 picture of progress.

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The finished distal half of the cannon barrel in pine.  If I stuff up the brass version at least I can have a wooden barrel. 

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Roughing the barrel in brass.  1mm cuts, feed 100mm/min.  It took almost 50 minutes for this section, and about 15 minutes for the breech section.

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The barrel mouth.  No gouging resulting from the 22 degree HSS cutter.

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Finish was quite good.  Will require minimal polishing with ScotchBrite.

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The workpiece was reversed in the lathe, the Z zero carefully set, the X unchanged, and the breech end turned.

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.

 

New Gates

I decided (well, to be truthful, SWMBO decided) that I needed to fix the gates which divided our front and back yards.  They were about 80 years old, and I had rebuilt them soon after we moved in 40 years ago.  About a decade ago I installed tensioning wires on a turnbuckle to counteract the sagging, but wear and tear and lack of maintenance painting had resulted in the main joints rotting, and so I decided not to fix them again, but to replace them.

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They are actually falling apart.

I have been progressively getting all of the iron railings around the house stripped, dipped in molten zinc, and powder coat painted.  For some reason the molten zinc dip is termed “galvanizing” here.

So the new gates would be made with steel SHS (square hollow section) frames, and aluminium slats.  I would happily have just copied the old wooden frame design, but SWMBO, who is an architect, decided that would not be “right” in steel, and that the steel frame would have to be the same shape as the surrounding brickwork, which is a sort of Tudor arch.  Why we have Tudor arches in Oz is a mystery.  Except that back in the 20th century, there was a “British to the boot straps” cultural cringe, and lots of the aspirational class houses tried to look as British as possible.  Paradoxically, although I am a confirmed  republican, I quite like the “mock Tudor” design.  And the house remains cool even in stinking hot weather…. but I diverge.

There has been some ground movement over the years, with the result that the arch is no longer symmetrical, so each gate is different.  So I used thin MDF to trace the arch shape for each gate.

With the MDF pattern, I attempted to roll the arch shape in the 50×50 SHS (2″ x 2″), but that was a failure.  The SHS did eventually eventually develop a curve, but at the cost of so much lateral distortion, bulging at the sides, that it looked terrible.

So I used a technique that I had used years ago when I made classical guitars, that is to make multiple cuts in the material leaving a thin intact edge, and then making the bends.  Each gate required 13  cuts.

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The steel SHS, roughly bent after making the multiple cuts.

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Then a wire bowstring and turnbuckle were used to hold the shape, while tack welding.  The turnbuckle was adjusted after each cut was welded, to get the curve as close as possible to the line on the MDF.  Earth clamp at bottom, turnbuckle at top.

The curve is not absolutely smooth, but it satisfied SWMBO.  Lucky that her eyesight is not so sharp these days.

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After welding the frames, the the frames and hinges were G clamped into position.  I used the original blacksmithed hinges.  The hinges were welded, and the frames were finish welded.  My eyesight is not too good either, and my welding shows it.

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The aluminium slats were drilled, temporarily screwed on, and shaped.  The catches and bolts were temporarily attached, then the whole lot was disassembled. 

The steel was hot zinc dipped, then after some finishing with a file, the steel and aluminium parts were powder coated.

The whole process took about 2 weeks.

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Almost finished.  SWMBO is satisfied.  Phew.

Now back to the cannon.

Making a Cannon Barrel is boring

The bore in my 1779 naval cannon is 14mm diameter, 270mm deep.

I made a D bit from silver steel, as per the Jerry Howell plans.  I tried it without heat treating, but it blunted after  boring a couple of centimeters  so I heated it red hot and quenched it in water, then annealed it  and resharpened it. There were  no further issues with edge holding.

I then tried it without, then with, a preliminary drilled hole in some scrap.   I have decided that it is better to give it a starting hole of the correct diameter.

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This is the setup.  The 50mm brass rod is held in a 3 jaw chuck, and the tailstock end held in a centre while the chuck jaws are tightened.  The bore is then started with a drill which is accurately sharpened.    Then the D bit is fitted, and the deep boring job starts.  I used an accurate 3 jaw chuck in the tailstock to hold the D bit.  The headstock does not accept 50mm stock, but the 3 jaw chuck does, albeit with some stick out.  Once the D bit enters the workpiece, it acts to stabilise the workpiece.  The whole process was easier than I had anticipated.

 

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Each peck of the  bit advances 2-2.5mm.   The D bit is withdrawn and the chips are cleared.  Initially I used  a small brush, but as the hole deepened, the brush was replaced with a compressed air blast, delivered through a small bore copper pipe.

The 270mm bore took 2 hours to complete.  It was not a boring job.  I was anxious not to muck up the hefty lump of brass.

Next to drill the trunion holes in the barrel stock.  That will be straight through all layers of the barrel.  (retrospective note added later…  The trunnion holes were stopped short of the bore, and I was just very careful to keep the holes at 180 degrees and in line)

Then to turn the exterior of the barrel.  There will be a video if that is successful.

Then to silver solder the trunnions to the barrel in one piece.  Then to use the D bit to rebore the barrel, removing the trunnion rod which is obstructing the bore.  Some readers will not agree with this method, and it is not according to the Jerry Howell plans, but it does ensure that the trunnions are exactly in line with each other.  Silver solder, if properly used, is said to be as strong as the parent metal, so I believe that I will not be compromising the integrity of the barrel.   The main disadvantage is that the finished exterior of the barrel will need to be held in the 3 jaw chuck during that final D bit reboring.  I have not quite worked out how to do that, while avoiding marking the finished brass surface.

 

1779 Scale Model Naval Cannon

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That bit of brass is 300mm long, 50.8mm diameter.

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And it weighs 5.1kg  (11.24lb).  Watch this space for progress.

More Australian Wildlife

No, this is not about venomous snakes, sharks, spiders or crocodiles.

In common with a lot of Australian households we have uninvited guests in our house.

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Our broom cupboard.

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Brushtail possums.  Harmless.  A bit noisy at times, especially if there is a turf war caused by an intruder.  My wife feeds them with tidbits of apple.  And they love grapes.  The baby in the first photo is quite tame, totally trusting my Dr Doolittle wife, but not so sure about anyone else.  We don’t allow them access into the human areas of the house, and we are puzzled about how they access the broom cupboard, because there is a storey above.

They are a protected species, and it is illegal to trap them or harm them.  We (SWMBO really) decided that we might as well encourage one family of possums and hope that they would fend off newcomers.  After a few years of this family we are quite comfortable to have them living in our roof space and between floors.  But we do need to fore warn human visitors about the occasional noisy screeching.

 

24 Pounder Naval Cannon

A half day in the workshop today, and the naval cannon carriage is taking shape.

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The pieces at this stage, just push together.  A few more bits of ironwood to be machined, then for the fun time… machining the cannon barrel.

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Ironwood cannon carriage, sitting on an ironwood kitchen table.  SWMBO is impressed! “it is looking interesting!”  Wait until she sees the brass bling.

DESERT IRONWOOD

Some decades ago I made a table for our kitchen.  (cannot find  photo just now, will add one later)

I bought the wood from a wood recycler.  He removed trees from Melbourne suburban gardens, then cut them into slabs and air dried them.

I recall that I paid about $AUD 1000 for the 6-8 planks.  They were about 40mm thick and 300mm wide and about 2.5m long.  They were so heavy that I could barely lift them.

I have since learned that they weigh 1.1 to 1.4 tonnes per cubic metre, which is at the high limit of wood densities.

The tree must have been 400mm diameter, because some slabs still had the bark attached to both sides.

The wood has a beautiful dark brown colour, with almost white sapwood solidly attached. It is unbelievably hard, and I struggled to machine it with my thicknesser/buzzer.  Also, it was the most reactive wood I have ever worked.  When planed or thicknessed it would bend and react totally unpredictably.   My 40-45mm thick planks ended up 25-28mm thick and even then they were not totally flat.

But SWMBO liked the table, and it still is the main meal table in out house.  One of my daughters requested a similar table, which I made from Gippsland Blue gum, another spectacular dense hard Australian wood.

The ironwood has survived kids dancing on it, steam engine demonstrations, being used as a work bench, not to mention many meals with never a table cloth.   And the wood itself is unmarked!  The polish has disappeared in places, but the wood itself seems impervious to damage.

To get to the point of this post, I am currently making a 1779, 24 pounder, 1:10 scale naval cannon.  Jerry Howell design.  About 300mm (one foot) long.

When I was looking in my shed I considered various woods for the carriage-base.  I considered some black walnut, which was recommended, but it seemed a bit light in weight and colour.  I considered some Australian redgum, which polishes beautifully, and is dense and tough, but it is a bit too red.  Some African Odum looked possible, but the figuring is a bit plain.  Then I found some ironwood offcuts from the table job, and the decision was made.  Ironwood it is.

So here are the initial photos of the carriage parts.  They were machined on my metalworking mill, using HSS cutters.   I CNC’d where possible.

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Ironwood after conventional thicknessing.  Tearouts are a problem.

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Ironwood after surfacing with a 1″ endmill.  Here I am CNCing the profile of the carriage.  3000rpm, 500mm/minute.

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After milling, I am tempted to just oil the surface.  The edges are sharp, like milled metal.

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CNCing the wheels.

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A little deburring or with wood is it called defuzzing? required

Watch this space for progress on the cannon.

There are some technical challenges, including deep boring 14mm diameter 275mm deep, making a tiny dovetail in the ironwood,  and turning the barrel from 50mm diameter brass.

Homemade lathe with ONE MICRON accuracy.

Watch the video.  It is inspirational.

Boxford CNC lathe (5)

The following pictures and video were supplied to me by Stuart Tankard.

They show the rarely used tailstock in use, supporting a relatively long thin workpiece.

The lathe is Stuart’s, and his control panel is fixed to the lathe cabinet.  (Mine is an identical machine except that I use a  wireless MPG).

The tailstock is the part coloured bright yellow, and it normally sits unused in a drawer, or hinged down and out of the way.  As you can see however, it occasionally is useful.

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Stuart’s lathe.  Note that the G code for the part was generated by a program called EZILATHE.   I also use this very handy program.  Ezilathe is a free download.

 

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The part is the first step in making a link for the beam engine which Stuart is completing.  The headstock end is held in an ER collet.  The tailstock contains a small roller bearing held in a shop made fitting.  After turning, the tear drop ends will have flats milled onto the sides, then holes drilled and reamed for shafts.

Check out the following Youtube video to see Stuarts lathe in action.

Milling a taper in thin steel

I was reading an article published by The Home Shop Machinist today, and I was very surprised to see my name as the author.

I had submitted it to HSM several  years ago, and had totally forgotten about it.

I had to read the article to remind myself how I achieved this neat little trick, of machining an exact 1.5 degree taper in a very thin workpiece.

Click on the link below to see the short article.

 

Milling a Taper in Thin Steel

December Heat

The temperature outside my workshop is 43 degrees centigrade in the shade.  For readers in our antipodes, ie the northern hemisphere, that is 109.4 degrees fahrenheit.

I remember working on a farm when it was 45.5/114 degrees.  I was hoeing vegetables.  And coping quite well, with frequent and copious water intakes.   But I was age 17.  I could do a lot of things at age 17 that I would not consider now at age 65.  My workshop is not heated or cooled, so when the temp exceeds 35/95 I give it a miss.

We have had a very dry spring, so the grass and the undergrowth in the bush is tinder dry.  There is a hot gusty wind.  I can smell smoke in the air.  There are bushfires somewhere.   We  have had the warnings from the authorities about dehydration, and fire plans.  Those who live in fire risk areas were advised to activate their fire plans yesterday, and leave homes, farms, and go to safe areas.  No longer are residents advised to fight fires and protect their homes on days like this.  It is just too dangerous.

I live in a city (Geelong) about an hour drive from Melbourne, and today I am babysitting in Melbourne.  When we go home this evening, we drive on a 6 lane freeway to get to Geelong.  I remember some years ago,  a grass fire swept across that road, incinerating cars and motorists, with many deaths.   On the freeway!  

So add bushfires to that lovely list of Australian nasties.  Along with venomous snakes, spiders, great white sharks.  But hey, only the police and crooks carry guns here.  If your neighbour gets cross with you, it is very unlikely that he will be back with an automatic weapon to take out you and your family.

Hopefully it will be a bit cooler tomorrow, so I can do something interesting in the workshop to write about.

 

 

A Collet Chuck for the Colchester Lathe

I recently bought a blank chuck backing plate on Ebay, hoping that it would fit my Colchester lathe.  It was $AUD110 plus postage, which, if suitable, would be an excellent price, but it was a gamble.  It was old new stock.

When it arrived I cleaned off the old, hard grease, and nervously presented the backing blank  to the lathe headstock.  It fitted perfectly!  The seller had another identical blank backing plate, so I bought that one too.  Components for the Colchester are not readily available, so I was very happy with this find.

I had a use in mind for both of the backing plates, and a few days ago I machined up the first one as per the following photos.

 

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The cast iron backing plate blank had a tough skin which a high speed steel cutter would not penetrate. So I use a carbide insert tool cutting 1mm deep to break through the skin. I finished the contact surface with a HSS tangential tool. (A diamond cutter from Eccentric Engineering)

 

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The C5 collet chuck.  I have had this chuck for a few years, purchased from CDCO Machinery (USA), but rarely used it because I was not satisfied with the accuracy.  I was very interested to see whether a very careful installation on the Colchester lathe might be more satisfactory than on the previous lathe (a Chinese lathe).  

 

 

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Checking the runout off the newly installed collet chuck. With a piece of 10mm diameter silver steel, the total measured runout was about 0.005mm. Good enough.  The backing plate is larger than required, but I will leave it as is in case I ever use it for another, larger chuck.   C5 collets will hold round stock 2-26mm diameter, and some common square and hexagonal sizes.   Very useful.

ACUTE TOOL SHARPENING at GEELONG MODEL ENGINEERS’ EXHIBITION

One of the tool displays at our exhibition last weekend (see previous post) was by ECCENTRIC ENGINEERING.  Eccentric Engineering is well known for the Diamond Tool Holder, which is a favourite lathe tool holder for most of us who use metal working lathes.

However I was more interested in Gary Sneezby’s (Owner-engineer of Eccentric) new tool, which is a tool sharpening system for use with a bench grinder, named “The Acute Tool Sharpening System”.

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Gary demonstrating the Acute Tool Sharpening System at the GSMEE exhibition.

 

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The Plans and assembly diagrams, in a bound booklet.

The system is available as a complete working unit, or a kit of semi machined parts and plans, or plans only.

See the Eccentric Engineering Website for a complete description of the system and prices.  eccentricengineering.com.au

I bought the kit of semi machined parts, and the booklet of plans.  Cost (show price, no postage) $AUD250.  This is an excellent price for the 50 or so laser cut parts, quality die cast handles, all fasteners, Allen keys, detailed plans.

 

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2 of the 33 pages of plans and diagrams.

The plans are excellent.  They are clear, easily read, and large.  There are no instructions, but a DVD is planned.  Gary is contactable by phone for construction advice, if needed.

After 4 half day workshop sessions I am well into the construction.  The laser cut parts are accurate within 1mm, and drilling points are accurately centre drilled.  Gary pointed out that the drilling points are more accurately positioned than the laser cut part perimeters.  That necessitates drilling centre holes (and the other holes) and using a mandrel to enable accurate turning of circular components.  He also advised that HSS cutters be used in preference to carbide tipped tools.

I found the parts to be very closely dimensioned to the finished parts.  The table top measures 150x150mm, and I found the flat hardened steel to be mildly bowed, to the extent of 0.38mm.  That is probably due to heat distortion from the laser cutter.      Some attention on the press straightened out the plate to less than 0.05mm bowing.   I might touch it up on the surface grinder, but that is probably unnecessary, given the way the system functions.

I had a machining accident with one part.  It is useable, but will need to be replaced.  I rang Gary, and the new part is in the mail.  Now that is service.

Progress to date….

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The sharpening system is starting to look serious.  It consists of a base, top plate which is adjustable for tilt and height, parallelogram arm, slide and toolholder.

 

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It looks interesting. Not sure how it works yet (Much clearer since watching the YouTube video at the end of this blog). Still some parts to be made-machined. The notch at the top is where the grinding wheel fits.

 

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The underside. Nice use of O rings to lock the adjustments into position. The cast handles are good quality.

 

Another session or two in the workshop should see this project completed.  I will report on how it performs  in a week or two.  I expect that it will be a lot quicker and simpler to use than the Quorn.

Watch the YouTube video by Gary to see how it works.

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

I needed to make a form tool to make the base for the air pump on my triple expansion steam engine.

It required a 1/4″ radius section and a 15 degree straight section.

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The dimensions for the cavity in the air pump, and the cutter to produce the cavity.  And the piece of cold saw blade which I used to make the form tool.

I considered machining the arc and the straight sections separately, but I did not have suitable tools, so I made a form tool.

A friend had previously suggested using steel from a broken cold saw blade to make form tools, and on this occasion I used his suggestion.  (Thanks Manuel!).

The blade was 1.6mm thick which was ideal.  I had some trepidation about cutting it.

The broken cold saw blade. The steel is superb.

The broken cold saw blade. The steel is superb.  Painted with layout dye.  The air pump base is visible lower right of photo, bolted to the engine base.

 

Using an angle grinder with a 1mm cutting disk. It cuts through the cold saw b

Using an angle grinder with a 1mm cutting disk. It cuts through the cold saw blade easily.  Like a hot knife through butter …  almost.

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Grinding the cutter to shape on an aluminium oxide wheel.

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Grinding the 1/4 inch radius arc.

Marking the shape of the form tool cutter

Marking the shape of the form tool cutter

Curodtting a 1.6mm slit in 10mm mild steel

Cutting a 1.6mm slit in 10mm mild steel rod.

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Initially I fastened the cutter steel to the rod using 2 grub screws, then, after checking the dimensions and the 15 degree angle I cut it to size. In use, I found the grub screws would not hold the tool steel securely, and I eventually silver soldered the join.

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The tool, prior to soldering. I ground the relief angles on my Quorn T&C grinder. (See old post). Except for silver soldering the tool steel into the rod, this is the finished tool.

 

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Commencing the machining of the air pump base cavity.  I had planned to do the machining using a boring head on my milling machine, but quickly realised that would not work. So I used the recommended method of a 4 jaw chuck on the lathe.  The 45 year old 4 jaw is still in excellent condition.

The end result. The complex cavity was initially centre drilled, drilled then bored to size. Then the home made tool was used to machine the undercut cavity. It worked perfectly!

The end result.
The complex cavity was initially centre drilled, drilled then bored to size. Then the home made tool was used to machine the undercut cavity. It worked perfectly!

I learned about using cold saw blade steel as a source of tool steel from Manuel.  I am aware of a professional contract machinist who uses this method to turn complex shapes in brass and steel, in preference to using a CNC lathe.

The material can be heated to red heat, (during silver soldering) and it does not lose its superb ability to take and retain a sharp cutting edge.  Very impressive.

Steam Powered BBQ Rotisserie.

I want one of these on my back verandah to run the BBQ rotisserie.

Seen in the Vintage Machinery Shed, at The Geelong Show.

Click on the arrow to see the driving mechanism.

 

Cheap Engine Turning

A few posts ago I posted some photos of the Koffiekop Stirling Engine, the top plate of which I had decorated with “engine turning”.  I had borrowed the engine turning tool and it worked well.  But I really wanted the circles to be bigger than the 5mm diameter which the Brownells kit produced.

Today I experimented with disks punched out of metal polishing material, glued to the end of same diameter dowel.  (1/2″ = 12.7mm diameter).    I used Super Glue, and no problems with adhesion.

The dowel was attached to a chuck in a drill press.  Running at about 200-300 rpm, and pressing firmly.  No extra cutting compound ( I imagine that these metal polishing pads already have an imbedded cutting compound).  If I was using washing up Scothbrite  type material, I would expect to have to add a cutting compound.

The steel I was testing had surface rust.

Very happy with the result.  Next time I will use CNC positioning to pattern the circles, and overlap the circles so the crappy rusty steel disappears.

I understand that if engine turned surfaces are oiled, they are relatively rust resistant.  Presumably some oil remains in the microscopic grooves.

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The top tool shows the tool after considerable use. It is a bit worn, but the thinning is mainly compression of the material. Compared with an unused tool below. And the surface rusted steel, which has had the tool applied in a semi random pattern, at the bottom of the snap.   (it is a home made tangential lathe tool sharpening jig).

 

Making Small Gaskets

My Bolton 12 Beam Engine is a steam engine, but to date, has run only on compressed air.

Compressed air, is invisible. Any leaks, might make some noise, and show up as a dirty oil leak, but are not visible to a casual observer.

In contrast, steam shows up every leak.

Our club is having its annual exhibition at The Geelong Show, in 2 weeks.  (See the post from 12 months ago about The Geelong Show)

Steam is available so I have decided to show my Bolton 12 beam engine, and to have it running on steam.

That has required making a steam connection and removing the compressed air connector, And more importantly, making every joint in the steam-air line,  steam proof.

So every join has been opened and a gasket inserted.  Some of the gaskets are oiled brown paper, and some are more permanent “liquid” gaskets.

Making the gaskets was a new and interesting experience, so I decided to make a photographic record.

I made the gaskets from brown paper.

I required 6 of these small gaskets, and 2 larger ones.

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More components ready to have gaskets installed

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Step 1. Make an impression of the surface in the paper using finger pressure.  Do not allow the paper to move.

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Step 2.  Continuing to hold the paper securely, locate the bolt and steam holes using a pin.  

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Step 3. Using an old centre drill, enlarge the pin holes. Rotate the centre drill anticlockwise to avoid tearing the paper. Push the the drill firmly while rotating it, and continue to hold the paper firmly against the surface.

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Step 4. Use the fine scissors to remove the dags. A delicate touch is required.  Use the ordinary scissors to cut the outline.

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It looks like it should do the job.


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The reassembled beam engine.  The displacement oiler, and rope driving pulley have been added since the last photos were posted.

Amazingly,  after reassembly, I had no left over bits.  If it works on steam as planned, I will post a video.  Watch this space.

Model Marine Boiler and another Koffiekop.

At the recent Geelong Society of Experimental and Model Engineers (GSMEE) meeting, several interesting models were presented, including my Koffiekop engine.   And another Koffiekop, this one by Stuart T.

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Stuart T is an expert engineer and machinist. He CNC’d most of the components in his engine, and has enough spare parts to make another 6 of them. He says each part takes a couple of hours to draw and program, then 5 minutes of machining to spit out half a dozen.

Another most interesting model is the marine boiler by Rudy pictured below.  Rudy was a marine engineer, and some of his ships were steam powered.  This model is made from his memory of one of those.  The odd external shape is to conform with the ship’s hull, starboard (right hand) side.

Model ship's boiler. it is approx 300-400mm high. The fire box is stainless steel. The copper boiler and water tank and superheater were TIG welded. The water tubes are silver soldered.

Model ship’s boiler. it is approx 300-400mm high. The fire box is stainless steel. The copper boiler and water tank and superheater were TIG welded. The water tubes are silver soldered.

The water tubes, super heater and boiler.

The water tank, water tubes, super heater and boiler.

The water gauge was scratch built by Rudy. The pressure gauge was bought.

The water gauge was scratch built by Rudy. The pressure gauge was bought.

Not sure what these attachment points are called, but they look interesting coming off the hemispherical ends of the boiler.

Not sure what these attachment points are called, but they look interesting coming off the almost hemispherical ends of the boiler.

Rudy made the nameplate on an engraving machine, then formed the domed shape.

Rudy made the nameplate on an engraving machine, then formed the domed shape.

Rudy has pressure tested the boiler to 100psi.  He reckons that it would be good for 200psi.  He tested it with compressed air, submerged in a barrel of water.  That would show any leaks.  And if it did happen to blow, the force would be diffused by the water.

Stirling Engine Failure. Now Successful!!

The Ridders “Bobber” Stirling engine which I made in 2014, and which defied all attempts to make it work, is now functioning beautifully!

After I completed the Koffiekop engine, and saw it working, I realised that I had not been adequately  particular with some of the machining aspects of the Bobber.

So I took the Bobber off the shelf, took it apart, and remachined the bore, made a new piston, and a new connecting rod bush.  Then I polished the bore using Gumption (see old post about Gumption) on a wooden dowel which was turned precisely to the correct diameter.  I was not concerned about some splits in the wood, as they acted as reservoirs for the Gumption.  After cleaning out the Gumption residue the bore was ultra smooth and shiny.   The piston slid easily on its own (miniscule) weight, and the sliding ceased when the top end was blocked with a finger tip.

I experimented with fuels (olive oil too much carbon deposition, but methylated spirits fine), number of ceramic ball bearings (three specified in the plans, but two seemed to work better), and most importantly, and serendipitously (that one’s for you John), reversed the direction of the flywheel.

See the video below for the result.

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Photo of the operating Bobber engine.  The white balls are ceramic bearings.  The piston is now made of graphite rather than the original steel, and I was particularly particular about the polish of the cylinder bore and the fit of the piston.

Video of the operating Bobber engine.

Stephenson’s Link Rods

The rods for the Stephenson’s links have been turned, threaded, silver soldered to flanges, and bolted to the eccentrics.  Still more to go.  A lot of time and effort for such small parts!

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3 pairs of yokes and eccentric rods, threaded, ready for silver soldering.

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The eccentric, rod and yoke, all joined.

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3 pairs of eccentrics and rods, one pair for each cylinder. 7 machined parts each, so far….

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Stephenson’s Link (2)

The next step in making the Stephenson’s link reversing mechanism, is to make the yokes for the links.  See the previous blog. I decided to drill and tap the BA10 holes, while the bar stock was still rectangular, for ease and precision of clamping the pieces.

BA, in case you are not familiar, stands for British Association.  BA threads were standardised in 1884, using imperial measurements (fractions of an inch), but to metric specifications.  All very confusing.  BA threads are rarely used these days.  Model engineers, instrument makers, and restorers of ancient British cars and motor cycles being the exceptions.  Builders of model engines often use them, because the bolt heads and nuts are nicely scaled for the models.

BA10 bolts are only 1.7mm diameter.  If a BA10 nut falls on the floor, it is gone forever.  I can barely see the thread of a BA10 bolt.  I shudder to think of using the even smaller BA12’s.

The tapping drill is only 1.4mm diameter.  A bit thicker than a human hair, (OK, many times thicker), but very delicate.  And the holes needed to be at least 5mm deep.  I do not possess a drill press capable of drilling such fine holes.  Any run out of the chuck, or excessive pressure would just destroy the drill bit.  Also, on working out the feeds and speeds of the drilling, it was apparent that the optimal drilling rpm’s would be 12,000 .  Twelve thousand.

So, once again, CNC to the fore.

I reattached the high speed head to my CNC mill, worked out the XYZ co-ordinates, and did a practice run on some scrap.  No problems!   Worked like a charm. 12000 rpm and feed 100mm/min.   Then to the actual job.   Centre drilled all pieces.  Then using the Pro-stop by Edge Technology  vice stop, repositioned the work pieces and deep drilled them using the 1.4mm twist drill, using CNC peck drilling at 1.4mm intervals.

Then to tap the holes.  The BA10 tap seems even more delicate than the 1.4mm drill.

I attempted to hand tap the holes, in the belief that holding the tapping handle in one hand, and the work piece in the other, would be the most sensitive system.  But these hands, which once performed microsurgery, were not up to the job.  It was inevitable that the tap would break in the job, so I abandoned the method before disaster struck.

The work piece was repositioned on the mill, again using the vice stop, and I used the CNC positioning to centre the tap fairly precisely squarely above the holes.  I made a spring loaded point to apply light pressure to the tap, and to keep it centered. (see photo below).  24 holes and about 2 hours later the threading was completed.   No breakages!

Tapping the BA10 thread.  Note the Protech vice stop, and the spring loaded centering tool.

Tapping the BA10 thread. Note the Prostop vice stop, and the spring loaded centering tool.

BA10 bolts OK.  Now to shape the yokes.

BA10 bolts OK. Now to shape the yokes.  (seen in the background.)

 

I had made a video of the CNC drilling, but the broadband downloading speeds here are so slow, that you will just have to imagine the excitement of the drilling.

OK, the video finally uploaded.  It is pretty crappy.  To see it, click on the link which follows.

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

Progress on the triple has slowed lately, partly because I am spending spare time on the Colchester lathe commissioning, but mainly because the plans for the Bolton 9 triple expansion steam engine are fairly vague and hard to interpret with respect to the Stephenson’s link reversing mechanism.  I think that I have finally got my brain around the workings of the mechanism, partly thanks to the many Youtube demonstrations, but mainly thanks to a series of articles in “Model Engineer” in 1985 -6, to which a colleague directed me. (thanks David).

The author of those articles has taken the trouble to document improvements to the original OB Bolton plans, and the improvements are much more comprehensible. (unlike this blog.)

My uncertainty was compounded by finding castings missing from the kit of parts which I had purchased.  I had taken the precaution of taking photographs of all of the castings when they were originally unwrapped, so I know that they were never there.  The supplier was not interested in rectifying the problem, so I am making the parts out of brass bar stock.

The following photos are the situation to date.

The eccentrics.  These are all split, and joined with M2 bolts.

The eccentrics. These are all split, and joined with M2 bolts.

The components of each eccentric.  The brass "halves", the bolts and the grub screw.

The components of each eccentric. The brass “halves”, the bolts and the grub screw.

The eccentric straps, also made in 2 pieces, joined with M2 bolts.  A groove is turned in each circle, and a corresponding ridge is turned in each eccentric.  All very precise and fiddly.

The eccentric straps, also made in 2 pieces, joined with M2 bolts. A groove is turned in each circle, and a corresponding ridge is turned in each eccentric. All very precise and fiddly.

Six valve rod "yokes" need to be made, but there was only one casting, so I have decided to make them all from bar stock.  The dimensioned bar stock (10x16x55mm) is seen here, with the "Model Engineer" article on the subject underneath.

Six valve rod “yokes” need to be made, but there was only one casting, so I have decided to make them all from bar stock. The dimensioned bar stock (10x16x55mm) is seen here, with the “Model Engineer” article on the subject underneath.

I will machine the yokes next week some time.   Space ships found in the Kazakhstan desert much more interesting, no?

On being a grandparent

Forget steam engines, Teslas, CNC, lathes.

At 65 times around Sol, the best thing in life is being a grandparent.  If you are a grandparent, you will understand.

Currently grandfather to John, my future apprentice, I am soon to become grandparent to a baby girl, whose name I know because little John told me, but I am not yet at liberty to disclose.

And…..   I have permission to disclose…..    also soon to become grandparent to identical twin boys.    More baby Johns!  Maybe with different names..

Identical twins!   I was an obstetrician/gynaecologist in my former life.   Identical twins! Pretty scarey.  But fascinating.  And wonderful.  One of my unfulfilled wishes was to be father to twins.  So I am to be a grandfather to twins.   Be careful what you wish for….   do I hear….  watch this space.  excited +++.

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

WTF is going on with Apple?

Since Steve Jobs died, I have had nothing but difficulties with My Mac.

I upgraded to the latest operating system for my Mac, and since then I am unable to insert photographs into my Word for Mac.  And it is a real hassle trying to insert photos into this blog.   That is one reason why my posts have been less frequent lately.

There has been a couple of patches for the latest Mac OS, but still problems.  Are they competing with Microsoft to be the most user unfriendly OS?

Anyway, I have not done much on my Triple expansion steam engine.  Any spare time in the past few weeks has been spent on the Colchester lathe.  The quick change tool post from the USA has been a big success.  I have been installing a digital read out for the past few days.  Finally hooked it up today, and it works.

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It is not CNC, but is the next best thing.  The imperial lead screw and imperial dials are much less relevant, when you have a DRO, which is set to metric.  And I really like setting the cross slide to diameter mode, being able to set the micrometer readings on the workpiece to match the readings on the X axis on the DRO.  Of course the Z axis readings remain set for actual movement, mm=mm.

The DRO came from China via Singapore, from thedrostore.  I have bought several DRO systems from thedrostore and they have always been relatively cheap, well packaged, fast, and with comprehensive instructions.   Thanks Scott!

The installation of cross slide scale on the Colchester was problematic, due to limited space, despite buying the “mini” scale, and I eventually positioned the scale on its side.  Said to be OK by thedrostore instructions.

I do not have space to install the Colchester in my workshop, so it is still sitting in a storage shed, on a pallet.  I am supposed to sell some other lathes, to make space for the Colchester, and to appease SWMBO.  But I have a real problem.  I just cannot part with any of my other lathes.  I obviously have a disease.  What to do?

New (to me) Toolpost for the Colchester

I have been looking for a replacement tool post for the Colchester Master 2500.  The one which came with the lathe was broken, and it had only 2 tool holders.  Hmmm…  Surely I would have noticed that during my fairly detailed inspection.  Other small bits were missing from the pile of accessories on the pallet too.  I should have taken photos.  The photos on Ebay were distant and blurred.  (I wonder why….).   Buyer beware.

So I have been checking Ebay Australia.  Only Asian copies, and not cheap.

Ebay UK.  A few genuine Colchester tool posts on offer, but very expensive.

Ebay USA.  Again, a few on offer, and one in particular looked interesting.  A Dickson style tool post, with 6 tool holders.  Said to be suitable for a US version of the Colchester, but a larger lathe than mine.   So a quick question to the seller about postage costs (where does Ebay come up with their estimates?  The Ebay estimate was double what I finally paid) and the seller agreed to put the items in two  “Flat rate boxes”.  I paid his buy it now price.  I took a gamble on the apparent lathe size discrepancy, figuring that I could resell the items on Ebay Australia if they were totally unsuitable.

4 days later, the parcels arrived.  I have bought quite a few items from the US, and invariably the service has been fantastic and fast.  I do feel a bit guilty about the energy and pollution involved with buying tools from far off countries, but there is no viable local alternative.

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The tool post was exactly the correct size.  The exterior  had been cleaned up, but the workings required some freeing up.  The tool holders were the same size as the two I had already, so now there are 8 tool holders….   a goodly number.  The brand label had worn off, but it appears to be exactly the same as the original Colchester.

The final cost?   $US250, plus $US125 for postage.   All up about $AU500.  Pity about the exchange rate.

More Drilling and Reaming of Deep Dark Places

A new tool came into my possession today.  It is a tapered, flexible, 1mm diameter reamer-file, made from nickel titanium.

It is used for reaming-filing cavities, and can go around bends to some degree.

The nickel titanium reamer.  1mm diameter tapering down to 10 microns.

The nickel titanium reamer. 1mm diameter tapering down to 10 microns.

It  operates at around 300rpm, and despite its flexibility, it has been known to break off in the job.

My dentist used it today to clean out a root canal.

He was quite happy to have a customer who was interested in the technology, and not totally focussed on the issue of pain.  As a matter of fact, it was not painful at all.  Yay!!

Apparently, if the tip does break off, and is not retrievable, it forms part of the new canal filling.  Nickel allergy does not seem to be an issue.  (not sure why.)  They cost about $25 each.  My root canal required 6-8 of them.

Just thought that you might be interested.

TRIPLE SH*T

The Bolton 9 triple expansion steam engine has 6 eccentric cams which drive the steam valves, 3 forward and 3 reverse.

The cams are each made as a split, offset disc.  The disc is machined after 2 pieces of brass are soldered together (soddered if you are north American), then the solder is melted so the eccentric discs can be attached to the crankshaft.

I spent a day machining the brass pieces and soldering it, and turning the discs.

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The brass rod with the soldered join, and the discs turned to accurate size

Another view of the eccentrics, still soldered together,  ready for insertion of screws then melting of the solder.

Another view of the eccentrics, still soldered together, ready for insertion of screws then melting of the solder.

Today I spent a couple of hours setting up the threaded holes to joins the disc pieces after the solder is melted away.

In the process of doing this I hit a wrong button, and fu**ed the whole job.  So I turned off everything in disgust, and spent the remainder of the day cleaning up my Quorn tool and cutter grinder, in preparation for an exhibition next weekend.

Sh*t happens when metalworking.   At least it will be quicker when I repeat this exercise in a day or two, if I can learn from the mistakes.

PROTECT YOUR SAUSAGE

Watch this video to see the future of circular saws and other dangerous woodworking and metalworking tools.

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This is the electronic unit which senses the human flesh touching the blade, and activates the heavy spring loaded chunk of aluminium, jamming it into the saw blade. The unit costs about $100, and the saw blade is invariably wrecked, with teeth being knocked off. But hey, would you rather lose a finger or a hand? I am told that if the unit is actually activated in preventing an injury, that Sawstop will replace it free of charge.  The unit can only be fitted to machines which are designed for it.  It cannot be retrofitted to older machines. 

BUYING A LATHE

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.

NO PICTURES, JUST WORDS.

I left my iphone at the grandson’s house after baby sitting last Saturday.  No biggie, but I could not photograph machining the steam valves and the steam valve cradles which I did today.  It also meant that there were no annoying interrupting phone calls  while I was doing the machining.  But I also did not have my iphone calculator, iphone angle calculator, or access to internet.    And I was aware that if I had a serious injury, I had no way of contacting help, since my workshop is quite a few kilometers out of town.

So, no photos until after next weekend, unless I crank up the old heavy expensive Nikon SLR.  (unlikely)

One item of interest.  I set up my CNC milling machine to cut MDF.  After seeing the fabulous toys made by my nephew Stuart, of Stue’s Shed, I decided that my grandson had to have some raptors and pterodactyls, so I did some Internet downloads from “MakeCNC” and cut out a raptor and a beetle and a Landrover.    It was fun.   And rather messy.    My grandson was impressed.  Although MDF toys are not very durable.  So I spent some time repairing broken limbs on the raptor and the beetle.   Maybe some photos when I get my iphone back.

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Grandson, beetle, instructions. Altogether, quite a fun session. I must have downloaded this one before I came home.

Triple Condenser Covers

The condenser covers are attached to the condenser body with BA7 screws.  The 4 inlets/outlets are drilled, surface machined, and screw holes tapped ready for the pipes.

The condenser covers are attached to the condenser body with BA7 screws. The 4 inlets/outlets are drilled, surface machined, and screw holes tapped ready for the pipes.

An unintentional ding from the milling machine chuck will need to be repaired before painting.

An unintentional ding from the milling machine chuck will need to be repaired before painting.

Covers for the inlet/outlet perforations were made, to enable testing for leaks.  No leaks found.

Covers for the inlet/outlet perforations were made, to enable testing for leaks. No significant leaks found. Slight weeping from the right hand cover will be stopped when the join is sealed or a gasket installed.

THE CONDENSER- not so easy afterall.

I had deferred making the steam passages (in the triple expansion steam engine), and moved sideways to an “easier” task, which was making the condenser unit.

It consists of a gunmetal box, with walls ~4mm thick, ends of 3mm brass, and 28 copper tubes soldered to the brass plates.  Plus end caps which required some milling and drilling ( see yesterday’s post).

I could not find my soft solder, so I used silver solder.  That was mistake 1. The heat source is an oxy actylene torch, and to keep the heat down I used a small tip. Mistake 2.  The end plates were first soldered (that is soddered if you live across the Pacific ocean) to the main body, and that seemed OK.

Then I fluxed the holes in the end plates, and fluxed the copper  tubes and positioned them into the end plates (mistake 3).  In view of what happened, I suspect that much of the flux was wiped off while pushing the tubes into position.

The water tubes silver soldered to the end plate.  The first end soldered, and it had multiple leaks...

The water tubes silver soldered to the end plate. The first end soldered, and it had multiple leaks…

The second end silver soldered, and it was perfect!  No leaks, looked neat.

The second end silver soldered, and it was perfect! No leaks, looked neat.

So, one end soldered without a hitch, and the other needs to be re-done.  Why?

3 possible reasons.

1. The copper tubes protruded further on the bad end, and it was more difficult to position the soldering rod in the in-between joins.

2. I used more heat on the good end.

3. It is likely that the flux was retained more on the good end.

So I am maintaining a well exercised tradition of learning from my mistakes.  I am sure that I have made mistakes 2 and 3 only a few times before.

So how to fix the leaky end??

1. Apply more flux and solder to the leaky bits?  Tried that.  Didn’t work.

2. Expand the copper tube ends with a tapered drift?  Tried that, and it helped, but still not enough.

3. Disassemble the leaky end by melting the silver solder and re-doing it?  After trying fix 2, I think that I have prevented this option.

4. Use soft solder to patch the leaks?  Not yet tried, but that is next.

If fix 4 does not work, I plan to remove and remake the tubes and end plates and re-solder the entire unit.

DARK PLACES

My decision to procrastinate with respect to the steam passages has worked, I think.  Several suggestions have come in, and I am intending to go with the one from Stuart.  And that is to angle the steam passages, which lengthens one on which I can use a larger diameter milling cutter, and to shorten the one under the steam port.  See the red lines for the proposed changes.

Red line plan alteration in the high pressure steam lines.  The other cylinder plans will be altered also.

Red line plan alteration in the high pressure steam lines. The other cylinder plans will be altered also.

While waiting for a light bulb to switch on regarding the dark places, I have not been idle.

I moved on to a part of the triple expansion steam engine build which I expect to be easier.  And that is the condenser unit.

The condenser is the box shaped protuberance attached to the columns.  I believe that its function is to convert the last dregs of steam, after driving the 3 pistons in succession, into water, for re-use in the boiler.

These are the components, machined and ready for assembly.

The condenser components.  There are 28 tubes, to be soldered into the holey brass plates.

The condenser components. There are 28 tubes, to be soldered into the holey brass plates.

The holes in the end plates have 0.5mm of material between them.  Tricky drilling, but a breeze for the CNC mill.

CNC drilling the end plates.  Centre drilling initially.  The 112 operations proceeded perfectly.  Did I say before that I love CNC.

CNC drilling the end plates. Centre drilling initially. The 112 operations proceeded perfectly. Did I say before that I love CNC.

End plate holes.  No breakthroughs, despite only 0.5mm between holes.

End plate holes. No breakthroughs, despite only 0.5mm between holes.

An end cover after machining.  The bosses and holes were CNC'd.

An end cover after machining. The bosses and holes were CNC’d.

CON RODS for TRIPLE -2

The con rod shafts have a taper of approx 1.5 degrees.  I turned the shafts between centres, using a tangential tool. The HSS cutter has a round cross section which gives a good finish, and automatically fillets the joins.

The con rod shafts have a taper of approx 1.5 degrees. I turned the shafts between centres, using a tangential tool.(a Diamond tool holder from Eccentric Engineering).  The HSS cutter has a round cross section which gives a good finish, and automatically fillets the joins.

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Of course left and right hand tools are required to do the whole taper.

Another jig! The con rod is difficult to hold accurately for milling, so I made a jig to assist. 10mm aluminium plate, with a cut out section to accept the con rod casting.

Another jig!
The con rod casting is difficult to hold accurately for milling, so I made a jig to assist.
10mm aluminium plate, with a cut out section to accept the con rod casting.

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The jig had to be made as accurately as possible. So it was milled square and parallel, then centre pins were installed to hold the casting by the previously drilled centres. A further pin with a sharp point was installed to stop the casting from rotating during the drilling and reaming for the gudgeon pin. That gudgeon pin hole was continued through the jig, so a large pin could be inserted to really hold the casting securely. It also allowed an accurate 180 degree rotation of the casting.

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A bit clearer with the swarf swept away!

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You can see the gudgeon pin in place, while further surfaces are milled.

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Close up of the jig and my metal workers’ dirty hand.   Just as well there is no more gynaecology.

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Progress!

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Not a clear shot, but here I am using the flutes of a milling bit to smooth the flat section under the gudgeon pin. Not ideal but it worked OK.  Tomorrow I plan to round off the external surfaces and mill the slot for the cross head.    Not much to show for a full day in the workshop, but it was fun…

CRANKSHAFT on base of triple.

The bearings are not accurate yet.  I just wanted to make sure that the crankshaft fitted into the slots.

It does fit, with minimal end play.

The main bearing studs are in place, but I am contemplating replacing them with smaller diameter studs, so the nuts which fasten the bearings in place (not seen in this photo) are a more realistic scale.

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Other People’s Triples

Not sure about the position of the apostrophe.

But if, like me, you enjoy looking at engines, then stop thinking about the apostrophe and watch the videos.

How a surgeon starts awkward, tiny nuts.

BA7 nuts are tiny. The thread is 2.38mm diameter. Admittedly, there are smaller nuts, but I have had so many problems with the BA7, that I do not want to even contemplate the even smaller ones.

If I drop a BA7 nut, I have about a 50% chance of seeing it on the floor. There must be a small fortune in BA7 nuts on the floor of my workshop, or wherever they bounce to.

The steam engine which I am currently building has several hundred of these tiny fasteners, and many of them are in inaccessible cavities, at least relatively inaccessible to my 65 year old fingers.

The more accessible BA7 bolts and studs can have nuts fitted with the assistance of a 4mm jeweller’s tube spanner. I added some usefulness to the tube spanner by turning its outside wall thinner, to decrease the space it occupies, but even so, there are many locations where no tube spanner, however modified, or open ender, or needle nosed pliers will reach, and fingers are required.

So, I had a brain wave yesterday, about a method of starting small nuts on relatively inaccessible studs and it works! This might not be an original idea, but it is to me.

It requires a sharp needle, on a handle, with an appropriate bend near the end of the needle. The sharp end of the needle is exposed. In my previous life I was a surgeon, so I have a supply of medical needles, and they are ideal.  A syringe makes a good handle.

The nut is placed on the needle, (carefully).

The needle point is placed in the centre of the end of the stud or bolt, carefully to avoid the nut slipping off prematurely, and the needle is angled so it is in line with the stud. The needle needs to be sharp, so it does not slip off the end of the stud.

The nut slips down onto the stud, and it can be spun with a finger tip until it attaches to the stud. The needle is then (carefully) placed away, and the nut is tightened down by whatever means are possible.

This method requires some dexterity, but it can change an impossible task into a merely difficult one.

Ps. If you use medical needles, make sure that they are new. Some diseases like hepatitis can be transmitted by needle stick injury.

The needle tip is pushed into the end of the stud/bolt.  The nut slips onto the end of the stud, and is then spun with a finger tip until it engages with the thread.

The needle tip is pushed into the end of the stud/bolt. The nut slips onto the end of the stud, and is then spun with a finger tip until it engages with the thread.

CRANKSHAFT – early steps

The triple expansion steam engine crankshaft has 6 main bearings, 3 big ends, and 4 positions where eccentrics attach.

It is about 240mm long, machined from 50.8mm mild steel rod.

The mains are turned from centrally positioned centres, the big ends from eccentrically positioned “centres”.

The centres were drilled on the CNC milling machine, after the locating the top of the bar

The centres were drilled on the CNC milling machine, after the locating the top of the bar

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The eccentric centres were calculated, and drilled using CNC to get the positions.  The longitudinal scribed line was used to position the other end of the rod.

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Turning between centres, using a lathe dog. This will not be a quick job.

And this is how I would like to make a crankshaft…

STEAM CHEST PROGRESS

Apart from contending with fauna in my workshop (a tiger snake) , I did actually make some progress today.

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All three steam chests are now attached to the cylinder block. This photo shows the high pressure cylinder steam chest. All of the screw holes are threaded and ready for the screws. More BA7 screws on order.

MAKING STEAM ENGINES, CIRCA 1905

I am republishing these photos, which I spotted on the net recently. They show a factory in about 1905 making steam turbines for installation in a ship. The belt driven machinery, and factory scenes I found fascinating.  There are also some pics of triple expansion marine engines.

Double click on a photo to enlarge it.

007_stitch_zps77e99731 006_stitch_zps054b3bae 005_stitch_zpsb3b28bf0 003_stitch_zps1d5a5cdd 002a_combined_zps3034921c 001_stitch_zpsf052a758 009_stitch_zpsc0136bc1004_stitch_zpsaa48624a006_stitch_zpscc231d7e

TRIPLE CYLINDER HEAD CAPS

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The head caps sitting in position.

Turning these fairly simple pieces should have been a doddle. Trouble was that they are relatively thin and soft and holding them in a three jaw chuck on the lathe was OK, until the rather sharp tool got pulled into the work. The cutter jammed, the workpiece was pulled out of the chuck and thrown across my workshop, with a a lot of superficial damage to the workpiece.
Fortunately, there was enough material remaining to machine out the dents and cuts. Also, it forced me to make a jig to hold the workpiece securely. Since the head caps are all different sizes, I had to change the jig dimensions after each head was machined, which was time consuming, but the method worked well with no further hitches.  Also, I changed from a tangential, sharp, high speed steel cutter, to a neutral rake carbide (and therefore less sharp) one, and no further dig ins were experienced.

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The jig for turning the reverse side of the cylinder heads, and the underside of the low pressure head (the biggest one)

 

Next I will drill and taps the holes for the small bolts which secure the head caps.  All 56 of them.  I sense some more CNCing in my near future.

TRIPLE BORING CYLINDERS

Today I bored the cylinders on the triple expansion engine.

Most model engineers would perform this task on a lathe, bolting the work to a faceplate or possibly using a large 4 independent jaw chuck.

The most accurate machine in my workshop is my CNC mill, so I decided to use the mill.

The setup is as depicted in the photo below.

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The cylinder boring setup.

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Cylinder boring complete. The setup took a couple of hours. The boring process also took 1-2 hours.

Of course, the high pressure cylinder needed to be center drilled, then drilled to 6, then 12, then 15mm, then bored to size 22.23mm.
Doing the job on the mill, I can be confident that the bores are all on the center line, all parallel, and the centers all correctly located. The intermediate cylinder finish was not acceptable, due to some chatter on the final cut, so I bored it out an extra millimeter to rectify the problem. The extra size will not matter. The piston (and rings?) will be made to fit the bore.

At the end of the session, I have left the setup intact, so I can check whether further processes can be performed using the same setup.

TNC lathe restoration completed.

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Miniature lathe mounted on an aluminium base, and hooked up to a new, variable speed motor. The pulleys were turned from aluminium.  The motor is controlled with a foot switch.  

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Headstock detail, showing the thrust bearing between the chuck and headstock, oil wells, pulleys and belt. I expect that an ER16 collet chuck will be used more often than the 4 jaw chuck.

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

Africa 447

We’re married, OK?

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The Most Fearless, Savage Animal of all

Honey badger, elephant bones

A Honey Badger. About the size of a medium size dog. We watched it walk past a leopard. Unconcerned, and unmolested. Lions leave them alone. The guide told us that they can kill a buffalo, and if provoked, will attack an elephant. Here it is walking behind the skeleton of an elephant.

Thick Skulls

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In Africa, you need to look both ways…

japanaese photograper

Dracula, Eat Your Heart Out.

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You are in my way!!

not happy 2

Botswana 2013

TRIPLE CYLINDER BLOCKS JOINED

The heavy chunks of brass which form the cylinders, and the intermediate cylinder valve chest, have been machined externally, and bolted together.

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The low and intermediate pressure block on the left, the IP valve chest (with the round boss), and the high pressure cylinder block on the right. All bolted together. Almost ready for cylinder boring.

The IP valve case cavity has been machined, but 3mm too wide. I think that this error will not matter, but if it does I will silver solder some extra material to get to the specified dimension.  (the external  dimension of the steam chest is deliberately left too big at this stage.  It will be blended with the cylinder blocks later.)

Now that these pieces are together, I can do the cylinder boring and complete the external dimensioning and finishing.

Cylinder Bases. Lathe or milling machine?

I read an expert treatise on making a double expansion steam engine, and I imagine that the comments applies to triples also.  One aspect emphasised the importance of accuracy in making the cylinder bases.  The parallelism of the surfaces, the concentricity of the piston rod hole and the other circular elements, and the thickness. The usual method for making these items is to turn them in a lathe with a 4 jaw chuck, then to reverse the item in the 4 jaw to turn the other face.  It is possible, but very fiddly and time consuming, and relies on expertise, patience, good eyesight, and a good lathe.   All of which are in short supply around here. A triple expansion steam engine requires 3 of these base plates, and while there are some common dimensions, the cylinder bores are all different.  Many of the screw holes are common to the 3 plates.  The thicknesses are all the same. To shorten this rather boring epistle, I decided to have a go at making the base plates on the CNC mill.  Given my previous muck ups, broken bits, crashes, this was a courageous decision, as evidenced by having to bin the first effort.  But the next 3 all seemed to work OK. First I studied the plans and noted the common elements, then I made a jig, with holes drilled at the common positions.

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The underside of the jig, showing the 5mm centre hole and the counterbored holes at the attachment points.

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The topside of the jig, after the first and second baseplates were drilled, thicknessed and shaped. The jig needed to be made very accurately, to retain position of the workpiece after it was reversed, so both faces could be milled. I am told that CNCers build up a collection of jigs over time. They are rarely used again.

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CNC milling the central boss. 20.48mm diameter, and accurate. Note the red positioning device, enabling the workpiece to be removed to check measurements, then replaced exactly in the same position.

To see a video of the CNC mill cutting the external profile click on the link below http://youtu.be/m0d5yuX96Uc

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The cylinder baseplates screwed to the columns. Some trimming of the column tops is required. The baseplates are centered accurately, as far as I can measure. Note that the central jig separating the columns has been removed, and the baseplates are now holding the column tops in position. The columns appear to be lining up correctly.

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The next example of using the CNC mill to perform a task which is normally done on the lathe. The mill cutter is travelling in diminishing circles, producing a central boss, and a flat surface.

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The boss finished to size (10mm dia) and flat surface.

BTW.  In a previous post I mentioned a 1 mm inaccuracy in a CNC milled part.  It happened again when I milled the first base plate, which ended up exactly 2mm smaller than programmed, and had to be re-made.  This time I discovered the cause of the inaccuracy….   I had used an 8mm milling cutter, but had forgotten to tell the CNC computer that I had changed from using the 6mm cutter.  The CNC machine did not notice the change, and cut the part exactly as instructed, very accurately, 2mm smaller than intended.  CNC machines are incredibly clever, but very very dumb.  They do exactly as instructed, even if the instruction is wrong.

Triple progress

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.

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The BA7 25mm bolts are screwed into place, and held there with with a nut.  The saw blade was attached to a 200mm long arbor which was shop made for the job, shown here about to trim the bolts to length, on the milling machine.

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The studs are trimmed to length, and the columns are sitting in place, temporarily held with 4 nuts each. 9 studs and nuts is total overkill, over- engineering, but it looks the part, no?

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After fiddling with the minute BA 7 studs and nuts, trying not to go nutty myself, I had some fun rough machining the lump of brass which is to become the low and intermediate pressure cylinders.

SHORT VIDEO OF CNC CENTRE DRILLING

To see the YouTube video, click on the link below.  Sorry about the shaky image.  I was holding my iphone in my right hand, while hovering my left hand over the emergency stop button, just in case.  But it all went perfectly.

Machining the columns on the Titanic Engine Model

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Deep drilling using CNC. The last hole was drilled manually, with problems. CNC rules OK!

A warm day today. Too hot to wear a shirt in the workshop. But no metal splinters from machining the brass and aluminium, and only one hiccup, which will be described.
The jig which I started yesterday, needed 9 more accurately positioned holes drilled and tapped M4.
So I programmed the CNC mill, only to discover that there is a limit of 8 holes able to be programmed. So the final hole would have to be separately positioned, and that was the cause of my problem.
Firstly, the 8 holes were deep drilled (30mm deep, 4mm diameter) after centre drilling. All done with the CNC.
All went beautifully. 2mm pecks, some cutting fluid brushed on.
Then I used the CNC to position the last hole, and centre drilled it manually, AND BROKE THE CENTRE DRILL IN THE JIG!!!
I did not want to remove the jig from the vice, because it was all accurately set up. But I could not see the broken high speed steel tip, so I removed the jig, and tried to dig out the broken tip. Unsuccesfully.
So the next method was to use an old carbide end mill, 4.5mm diameter, to drill into the hole and to break up the high speed steel fragment. That method worked, but at the cost of enlarging the accurately placed but incompletely drilled hole. Next step was to reposition the jig in the milling vice, then deeply countersink the hole, then complete the 4mm drilling operation. It seemed OK, but it later became obvious that the hole had moved about 0.5mm from where it was intended. I eventually used a carbide end mill to enlarge the entire hole, in the correct position, at 4.5mm diameter.  All a bit messy, but not fatal.

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The jig halves opened up, and the drilling positions which were entered into the CNC instructions.

Then the columns were drilled and tapped.  2 attachment points per column, so with 3 holes per column in the jig, there are 2 possible positions for each column in the jig.

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The columns to be attached to the jig.

A column on the wedges in the milling vice, rea

A column on the wedge in the milling vice, ready to be drilled and tapped.

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The columns screwed to the jig.

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2 columns are integrated with the condensing unit.

Re “Titanic” engine heading…   I get a lot more hits on this blog if I include the word Titanic.  OK?

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Now that all columns are attached in their final position on the jig, I can start hacking into them to produce some flat surfaces

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The columns sitting on the base in their correct position, using the jig.

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LP is the column for the low pressure, biggest cylinder. HP is the column for the high pressure, smallest cylinder. IP is intermediate. C is for the steam condenser.

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

At last!

A day on the steam engine.  SWMBO went to Melbourne to choose marble so I was free!!

After discussing my problems with machining the triple  expansion engine columns with the senior members of the GSMEE (Geelong Society of Model and Experimental Engineers),  I have machined a JIG to assist with this issue.

The JIG thickness is precisely the width between the columns (30.05mm).  It is made in 2 halves so I can bolt the columns from their critical surfaces which are the con rod slides.

I will use the CNC mill to drill the holes in the jig, and the matching columns, then finish milling the columns which are attached to the JIG.

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The jig for machining the columns. Not yet finished.

 

 

Bottom left is X=0, Y=0.  The photo shows the 4 countersunk M4 screws.

The holes will be centre drilled then through drilled 4mm. The columns will be drilled 3.3mm then m4 tapped.
Hopefully that will happen tomorrow if the workshop is not too hot.

You will see what I am intending with the next post.

MAKING GATES

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”.

Cattle yard welded joins

Cattle yard welded joins

The horizontals  and verticals could be cut at 45 degrees and mitre welded together.  Not quite the look desired.

Mitred join.  Not for these gates according to SWMBO

Mitred join. Not for these gates according to SWMBO

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.

Using the bometal hole cutter in the drill press.  A staged photo, but it does show how it happened.

Using the bimetal hole cutter in the drill press. A staged photo, but it does show how it happened.

The chosen method

The chosen method

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).

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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.

One pair of almost finished gates.

One pair of almost finished gates.  

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.

TNC Lathe renovation 3

SWMBO has “persuaded”me to make two sets of double gates for a Norlane renovators dream, so not too much happening in the machine shop.  Welding and cutting in our Australian summer is not fun.  The gates are ready to be hung so hopefully I might be allowed back into the play area in a couple of days.

I did get a few hours to put some colour onto the TNC lathe.  Dark green enamel sprayed with a “Badger 360” air brush.  First time.  Fun.  Not a fantastic result but OK.

I was quite impressed at how effective masking tape was, in keeping paint off machined surfaces.

This whole exercise is a practice run, so I minimise the chance of stuffing up when I paint the Beam Engine.

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Spraying the tailstock.  The other hand is holding the iphone camera.

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The Badger 360 in an aftermarket cleaning tank.

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The lathe bed and headstock with 2 or 3 coats of topcoat. The big bolts with nuts are to keep paint out of the bearings.

TCL lathe renovation 1

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.

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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.

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…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.

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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…

 

 

LATHE OBSESSION

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.

The cup of coffee is for scale.

The cup of coffee is for scale. (for sale if the price is right!)

4 jaw chuck. Not sure what the gears are for.

4 jaw chuck.  I have a nice 3 jaw TOS which will be installed.
Not sure what the gears are for or even if they belong to the lathe.

 

The muddy yellow-green-grey paint was revealed after an initial de-greasing.  The handles are brass.  All of the slides work, and there is no discernible wear.  The gibs are brass. One handle is broken.

The muddy yellow-grey paint was revealed after an initial de-greasing. The handles are brass. All of the slides work, and there is no discernible wear. The gibs are brass.
One handle is broken.

CNC Mill 11

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.

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An Improved Lathe Stand.


I was becoming a bit annoyed with my Asian HMC lathe.  It was noisy, and whatever I did with respect to feed rates, tool types, material etc, I could not seem ever to get a really good finish, and it did not seem particularly accurate.

I had spent a fair bit of time getting it level, and adjusting the tailstock offset, but the settings never seemed to hold for long.

The base was as supplied originally.  2 fairly solid sheet metal cupboards with handy storage compartments, and a rather flimsy piece of sheet metal joining the 2 cupboards.   Each cupboard had 4 adjusting bolts, ie 8 altogether, so levelling the lathe was tricky.  But the worst aspect was that it all seemed very flimsy.

The lathe on its original cupboard base

The lathe on its original cupboard base

So I decided to make a new base.

A visit to the local scrap metal yard yielded up a 3 meter length of 300 x 100 x 16mm channel.  Too heavy for 2 men to lift onto my vehicle roof bars, but easy with a fork lift.

Getting it off at the other end was tricky.  But I managed to do so without damaging my vehicle.

Cutting the channel with the drop band saw.

Cutting the channel with the drop band saw.

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I made the legs from some 100 x 50 x 3 or 4mm RHS, and welded it up.  It all seemed heavy and rigid.

I measured and drilled the mounting holes for the lathe bed.  The new base was at the same height as the original, so I was able to crow bar the lathe over onto the new base, hoping that it would not fall between the 2 bases.  It weighs several hundred kilograms, so a fall would have been messy.

Amazingly, the bolts dropped straight into the new mounting holes, after some manoevering with a podger bar.  Then I levelled up the base using bolts at the bottom of each leg, and a machinists level on the lathe ways.

The new base.  The channel is barely visible under the lathe bed and behind the legs.

The new base. The channel is barely visible under the lathe bed and behind the legs.

Levelling bolts at each corner

Levelling bolts at each corner

 

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Showing the channel welded to the legs, the cross piece, and the levelling bolts.

 

Then I did some test turning.

1. The lathe is appreciably quieter.

2. The work finish is definitely improved.  No unpredictable and odd grooves to mar the finish.

3. I have yet to measure the accuracy change.

4. Unexpected bonus.  There is a lot more storage space under the lathe than there was in the original pokey little cupboards.   Small items now live in the mobile chest of drawers unit next to the lathe, and big items such as the toolpost grinder in its box, are under the lathe.

More Inca stonework. Awesome.

Our guide at the MachuPicchu quarry explains how the Inca stonemasons chipped rectangular slots then hammered in wedges, or allowed water to freeze and expand, to split the stone.

Our guide at the MachuPicchu quarry explains how the Inca stonemasons chipped rectangular slots then hammered in wedges, or allowed water to freeze and expand, to split the stone.

MachuPicchu quarry

MachuPicchu quarry.  The piece on the ground has been split off, about 500 years ago, ready to be painstakingly shaped and fitted into a wall.  

A displaced, shaped block at Cuzco.  Shows how the block is shaped on all faces.

A displaced, shaped block at Cuzco. Shows how the block is shaped on all faces.

The blocks were fitted together, and then often joined with lead or silver, which was poured in a molten state into the grooves. Recovering the silver was possibly one of the reasons why the Spaniards demolished many Inca buildings.

The blocks were fitted together, and then often joined with lead or silver, which was poured in a molten state into the grooves.
Recovering the silver was possibly one of the reasons why the Spaniards demolished many Inca buildings.