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: steam engine

Another Triple Expansion Steam Engine?

Julius deWaal has drawn and published plans for model engines, most recently the Bolton/Bertinat plans for the triple expansion marine steam engine. The triple plans are available to download free of charge at ….

I made a model triple using the Bolton plans and castings, several years ago.

Here is a recent photo of my model triple expansion engine operating on steam at the Royal Geelong Show. In the background is a full size version, which is a permanent, operating, attraction at the show. My model is 250mm long, 250mm high, and weighs about 10kg. It has a Stephenson reversing mechanism, and an exhaust steam condenser, both of which work.

It was a difficult build, taking me about 3 years, with a couple of sanity restoring long breaks during which I built other models. The build was detailed on this blog. To check the progress photos and descriptions do a search on “triple”.

I was very happy to finish the build, and ecstatic to see it working on compressed air, and then steam. When exhibited it always attracts a lot of attention, with its myriad of small moving components.

But, I was a bit unhappy, because it does include some errors. These were partly due to the suboptimal plans, and more so to my inexperience. The errors are not apparent to a casual observer, but I know that they are there. They do not interfere with the operation on steam. I had considered making another, bigger, triple, but always backed away, due to the time, complexity, and cost.

But a friend recently sent me a link to the new deWaal plans. The link is below the first picture, above. The new plans are metric, very detailed, and TWICE the size of the originals…. i.e. a model built to the deWaal specs would be 500mm long, 500mm high, and probably weigh around 40kg!

I must be a glutton for punishment, or a bit nuts, because I am seriously considering making another triple, using the deWaal plans and not buying castings but using bar stock. And maybe using some home made castings.

So, watch this space…..

Portsmouth UK. 2 more great museums.

Not strictly museums.  Ships actually, but displayed as museum pieces.  Both incredibly interesting.  And I am not including Nelson’s “Victory”.  I had seen it 40 years ago, and after 5 hours of walking, my knees told me that enough was enough.


“Victory” as seen today.  Still the biggest crowd pleaser.  Now sitting on props in a dry-dock.

My main targets today were “Warrior” and the “Mary Rose”.

Warrior was built in 1860.  The age of steam was well underway.  But to date, warships were still sailing ships.  However the French were rebuilding their navy after their humiliating defeat at Trafalgar, and they had built the first propeller driven, steam powered, iron clad (wooden ship with steel plate cladding).  The Brits were not going to stand for that, so they built “Warrior”.  The most powerful, fastest battleship afloat, and more than a match for anything else in the world.  By the time it was built, the French and the Brits were allies, for a while.  Warrior was destined to never fire a shot in anger.

Today it sits moored at Portsmouth’s Historic Dockyard, and is a fascinating mixture of steam and sail, muzzle loaders and breech loading guns, Steel and wood.  It is a big ship, 127.5m (418′) long, and 9210 tons.  It looks a little odd to our eyes because it has no superstructure, except 2 funnels, and the foremast and mainmast are widely separated.


Steel framed, 18″ of oak lined, plus 4.5″ of steel plate.   The masts are steel, with wooden upper sections.  The figure head is a Greco-Roman warrior.   706 crew.

This ship could make 14.4 knots (27.7kph) under steam, 13 knots (24kph) under sail, and 17.2 knots (31.9 kph) with sail plus steam.  Not as fast as a clipper, but much faster than any other warship.


4.5″ (114mm) armour plating, plus 18″ (460mm) teak planking.


Traditional spoked steering wheels were duplicated on 3 decks.


Hundreds of Lee-Enfield percussion cap rifles were available.


And cutlasses, to repel boarders.  Muzzle loading cannon tools to left.


And Colt 45’s for the officers.

But the main armament was of course the big guns.


The gun deck was similar to that of the 120 year older Victory.   except that these are huge 68 pounders.  19 man gun crew for each.  A mixture of 10 x 110lb breech and 26 x 68lb muzzle loaders.


And the crew still slept in hammocks on the gun deck.  And ate there.


But they had washing machines  and lavatories (first ever warship with these)


and baths!


The steam engine, surprisingly was a relatively primitive, but powerful twin cylinder, single expansion, horizontal trunk engine of 5469hp, driving a single propeller.  The 10 boilers were box shaped, double firebox, no fire tubes.   22 psi only.


Coal was delivered in small coal trucks on rails, and shovelled into the firebox’s.  No gauges,  except in engine room.   853 ton coal stowage.

I have many more photos of Warrior, but I am down to my last few megs of storage, and I want to show some pics of the Mary Rose, which is probably the most stunning museum display I have ever seen.  I know that I keep saying that, but this really is…..

Mary Rose was a 35 year old warship which sank in 1545 during the battle of the Solent, against a huge French invasion fleet, while Henry 8 was watching.  No-one really knows why it sank, but the most popular theory is that bigger cannons had been installed, requiring low gun-ports to be cut into the the hull, and that after firing a broadside the ship had turned and the open gun-ports shipped a lot of water, which sank the ship.   Whatever, the ship was unable to be raised. Most of the hull gradually rotted and broke away.  But the parts which were under silt did not rot, and were still there when discovered over 3 centuries later.  In 1985 the remains were raised, and painstakingly preserved.  A museum to house the remains was specially built.  And it is stunning!  No other word for it.  Here are a few pics from today.


Mary Rose.  Pride of the English fleet.


and you know who.


About 1/3 of the hull remains, including most of the keel.


The bronze cannons are in fairly good shape.  Only real remains are displayed.


This is a breech loading iron cannon, made of strips and hoops of iron.  The ancient wood and iron has been treated for years with PEG (polyethylene glycol) before going on display.


Hundreds of ewe long bows were found, many still in their storage boxes.


And many skeletons.  This one was a bowman.  That humerus (upper arm bone) is massive.  There were 35 survivors out of the many hundreds of men on board. 


And a reconstruction of the bowman.


And sadly, a dog.

A most remarkable museum.  Add it to your bucket list.  Allow at least 2 hours.






BT. Before Trevithick.

Before Trevithick were Savery, Newcomen and Watt.  And way before them, Hero of Alexandria (1st century AD)

Thomas Savery, a military engineer from Devon, took out a patent in 1698 for a steam operated pump.  It had no moving parts, except some valves.

Savery-engine 1698

It had 2 low pressure boilers.  Steam from one boiler was introduced into one chamber, and water was then introduced which condensed the steam, forming a partial vacuum, which sucked up water from below.  Steam from the other boiler was then introduced, which pushed the water upwards.  As a pump it was a failure, and it is not known if any were made.  Modern reconstructions have also been unable to pump water successfully. But the patent lasted, and forced Newcomen to involve Savery with his invention in 1712.

Thomas Newcomen was an ironmonger and Baptist lay-preacher from Dartmouth, Devon, and he is the reason that I am currently in this pretty Devon town.  There is an original Newcomen “atmospheric engine” in Dartmouth.


(taken at an angle to avoid window reflections)

The Newcomen pump, (for pumping water from the mines was its purpose) also used the condensation of steam creating a partial vacuum, as its principle of action, and it was quite successful.   So successful in fact, that more than 600 of them were built, and they continued to be built well after the improvements of Watt and Trevithick, into the nineteenth century.  In the diagram above, the 22″ power cylinder is on the right, and the pump cylinder is on the left.  The genius of this design is that the pump can operate in the depths of the mine (or canal or military trench) while the engine remains above ground.

It is incredibly inefficient in thermal terms, converting only 1:200 of the energy from burning coal into the mechanical energy of the pump, but it was by far, more powerful than any pumps driven by man, horse, wind or water at that time.

The room in which the Dartmouth engine is housed is just bigger than the 15′ high engine, so pictures are difficult.


All wood, except the power cylinder on the right, and the pump and pipes (not seen).  The curved ends of the big wooden beam keep the piston rod and pump rod vertical.  Cylinder boring had not been introduced yet, so the gap between piston and cylinder was up to 1/4″.


The valves to admit the steam and water were originally operated by hand, but later some automated simple levers were introduced.  Note the square nuts (original).  It appears that the woodwork is mostly original, albeit repaired in places.



The pump connection


This power piston has a bore of 22″ (560mm), but they were built increasingly bigger, up to 80″ (2032mm).

The Newcomen engines were simple, and effective.  Their main problem was that they consumed vast quantities of coal.  They were widely used, but there was/are no coal deposits in Cornwall, and transporting coal from Wales was costly, and taxed.

James Watt‘s big contribution to steam engines was to add a condenser to the engine, which was separated from the power cylinder.  That doubled the efficiency.  He also sealed the top of the cylinder, so both strokes of the piston rather than just the down stroke, were power strokes.  But it was still a vacuum powered engine, and therefore had an absolute limit of working pressure of something less than atmospheric pressure (15psi).

Richard Trevithick‘s main contribution in 1800 was to increase the steam pressure available, by inventing the “Cornish boiler” which produced steam at 50psi, and even up to 145psi.  This more than doubled again the thermal efficiency of the steam engine, and made it much more compact, leading to his applications of steam engines in road vehicles, railway locomotives, ship engines, and industrial stationary engines (like my model dredger engine).


Watt modified Newcomen engine on the left, Trevithick dredger engine on the right. Size comparison.

Tomorrow I am driving to Portsmouth.  So I will leave the west country inventors of steam engines.  It has been a fascinating journey.

First stop, Fort Nelson.  To renew my acquaintance with the Ottoman bombard, which was the subject of my blogs several years ago.


First Steam Locomotive.

In 1802 a Richard Trevithick designed engine was made by the Coalbrookdale company.  Not much is known about it, but is recorded that the steam pressure reached 145psi!  Trevithick had previously operated his road steam locomotive up the Camborne Hill, but this was the first one to run on rails.

The next one was made for the steelworks at Merthyr Tidfil, Wales.  It was a Trevithick engine which ran on rails.  The owner made a 500 guinea bet with a rival (an astronomical figure.  Somewhere I read that it would be equivalent to a million dollars these days), and in Feb 1803 the engine towed 5 wagons, loaded with 10 tons of iron ore (or coal, not sure), and 70 odd bods, a distance of 10 miles.  There was dispute about whether the bet had been won due to some technicalities, and no record of it being paid, but it was a moral victory.  The age of steam had really begun.

The biggest problem was not the locomotive, but the rails.  They were not strong enough, and frequently broke.  It took the genius of George Stephenson to solve that problem, by using forged iron in preference to cast iron.  And his son Robert to increase the efficiency of the engine and boiler in the form of “Rocket”.  But that is another story, for 30 years later.

Unfortunately the original of the Merthyr Tidfil loco has not survived, but several replicas have been made, based on original drawings.  I saw one of them at Swansea, Wales, not far from Merthyr Tidfil.  Not a steaming day.  It does run.


Not great photos.  The lighting conditions in the National Waterfront Museum were difficult.


The typical big, skinny Trevithick flywheel, and driver’s wagon.


Square main shaft.  Hex nuts were not around in 1802.  


And that is a view that you don’t often see.  The pressure gauge is definitely a modern requirement, as I discovered with my dredger engine.


Notice the fish belly rails.  Originals were cast iron.  “Fish belly” shape to increase the strength, but alas, not strong enough.  Hex nuts again!  And those gears have modern shaped teeth.  Quite a few compromises in this replica.

And I have now arrived in Camborne, Cornwall, Trevithick’s home, and the site of his famous trial of the steam road loco.

I made a pilgrimage to Fore St (“Camborne hill”), then to his statue, to pay homage.


Richard Trevithick.  Genius.


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.




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.


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.




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.



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

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.


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 Dredger Engine- Valves

No workshop posts for a while because I have been making parts for the internals of the engine, and when installed they are not very photogenic.

Since the last post I have made the piston, piston rod and installed soft packing to seal the piston, made the valves and valve handles..



Stainless steel piston rod, bronze 20mm dia piston, and soft packing inserted into the machined groove.

Also made the throttle valve and steam direction valve.



This was the third attempt at making a steam valve.  I went slightly undersized with the first, totally buggered the O ring groove on the second, but the third one looks OK.



Good one (I hope) on the left, and destroyed one on the right.  The lathe tool bit into the bronze.



From left to right.  The bush, the undersize, the buggered, and the OK I hope.  and the plans.

And after all of that, and also making the throttle valve, I discovered a mistake in the plans.  A 1mm discrepancy, which I suspect was an arithmetic mistake on the part of the plan maker.  I decided to modify the valves, bush and valve block rather than remake the valves.



I machined 1mm off the faces shown in the photo, then spent some time prettying it up.  Then took 1mm off the valve lengths, and the valve bush.



This is what it looks like now.  All fixed.  Waiting for Viton O rings to arrive.  Looks OK IMO.









This is a short video of the first run of the Bolton9 Model Triple Expansion Steam Engine, which I have been building on and off over the past 3 years.

The video is a bit shakey, because it is taken on my hand held phone while I am using he other hand to operate the controls.  I really did not expect the engine to work!

It runs a bit roughly, and is still quite tight, but settles down in the final few seconds.

It is not running very smoothly, because it is on air rather than steam, and because it is probably only powered on the high pressure cylinder, and maybe a bit on the intermediate, and not at all on the low pressure cylinder.

The next day it would not run.  Very frustrating.  I suspect that one of the eccentrics slipped on the crankshaft, and threw the timing out.  Not the easily accessible low or high pressure valve, but the intermediate one, which needs another teardown to get to it.

But Hey!  It will work.  I can see the light at the end of the tunnel.

One of my readers has requested a description of the triple engine timing procedure, so that will appear on this blog soon.  Unless you have a particular need for the timing info I suggest that you give that post a miss.

Triple Expansion Steam Engine Cylinder Cocks

Some further progress on the triple.

I bought cylinder cocks from Reeves UK, and the picture shows them fitted.  In case I eventually install a mechanism to open all of the cocks simultaneously, they are in straight line, which necessitated making extension peices for the high pressure cylinder cocks.

The handles required bending to clear the pipework.

The cocks look a bit strange to me.  Too big, and the handles are wrong.   I am thinking about making a set from scratch.  But that can wait.


Drain pipes from the cocks will be installed at some stage.  Still deciding where to run them. And whether to join them into a common trunk.

FullSizeRender 7.jpg

The engine turns over by hand, but it is still a bit stiff.  There was a tight spot which took many hours to locate.  It turned out to be a valve rod thread which was about 0.5mm too long, touching the inside of the high pressure valve chest.   Fixed in a jiffy.

I hooked up the engine to a small compressor at 30psi, but general stiffness prevented the engine from rotating.  So I gave it an hour being rotated in the lathe at 200 rpm.  It is noticeably more free, and getting very close to working.  The valve timing is approximately correct (checked by my expert friends Thomas L, and Rudi V), but will need fine tuning at some stage.

Traction Engine Oiler

The oiler which had been made for the 3″ Fowler compound steam engine looked OK, with a nice rounded brass cap, but despite various adjustments I could not induce it to work reliably.  The pawls were very thin brass, not hardened steel, and the supporting bracket was very thin sheet steel which had little resistance to flexing.

I decided to replace the oiler.   I could have made one from the engine plans, but when I saw some photos of these Foster Lincoln oilers on scale model traction engines, I decided to purchase.


The one which I purchased was designed for a 4″ scale traction engine, bigger than my 3″ Fowler, but the external dimensions were similar to those specified on the Fowler plans, and the Fowler is a 2 cylinder engine.  So I decided to go “too big” than risk “too small”.

It arrived by mail today, from the U.K.   Cost £116 + £10 p&p from “Live Steam Models”.  Not cheap, but the quality appears to be excellent.   Heavy brass body, hardened steel pawls and ratchet wheel, stainless steel water drain, and a powerful spring operated pump.  The lid closes with good tight fit.  Some filing will be required on a cut edge of the lid, but no big deal.


The pump in the oil cavity.



My brother and I visited a well known local machinery enthusiast.  Some of my readers might be interested in the photos.


An excavator from the 1940’s, due for restoration.


Said to be incredibly noisy and heavy for the operator.


Excavator diesel engine works.


My miniature Fowler traction engine does not have a steam injector and I am considering installing one.  So here are photos from a full size Fowler, and another from a  Ransomes traction engine.


Fowler R3 steam injector, located near the bottom of the rear water tank.


Ransomes injector located similarly.


A pin, for a pin, for a pin, for a winch. (Fowler traction engine)


Why do the boiler stays have holes bored into them?  When a stay breaks it usually occurs on the inside of the boiler.  The break can be undetected.  If there are blind holes bored like this, steam will escape through the hole if there is a fracture, revealing the problem.


The countersink on the stay holes here is decorative only, serves no useful purpose, and probably weakens the stay.   The differential gear on the left is very worn, but still useable.



Ransomes traction engine on the left, and Fowler R3 heavy haulage engine on the right.  2 tonne rear wheel removed and chained to the post, while transmission gears are being remachined.


The ash pan from the Fowler R3, after 4 days of continuous steaming at the Geelong Show.  Of interest to me, because on my 3″ scale (1:4) Fowler the ash pan has been almost exactly scaled and I suspect that it would benefit from a redesign.


Kelly single cylinder traction engine.  Working condition.


Kelly engine.  Everything visible.  Note the very useful steam dome.


Fowler R3 nameplate.  I can see something similar appearing on my 3″ Fowler.


Front wheel on the Ransomes traction engine.  Both front wheels were torn off in an accident in 1920.  Going down a long steep grade at Shelford, Victoria, there was insufficient steam pressure to brake the traction engine towing a heavy load, so the driver deliverately crashed the engine into the road cutting, at considerable speed.  It was succesfully repaired by a blacksmith.  The driver survived.



The Ransomes engine.  The “Rolls Royce” of traction engines, according to the owner. (But I suspect that he prefers his Fowler).

So, I hope that you found these pics interesting.  John.


The following short videos show some of the engines on display by GSMEE in the Vintage Machinery Shed at the recent Geelong Show.  GSMEE is Geelong Society of Model and Experimental Engineers.  All engines are running on steam, except of course the Stirling engine,  the Farmboy, and the Atkinson engine.

These engines will be running again at the GSMEE exhibition 25-26 Nov 2017, at The Lifestyle Pavillion, The Geelong Showgrounds.  Several scale model traction engines, trade exhibits, outside entries, and the engines in the Vintage Machinery Shed will also be on show.  The Hatherly Challenge competition will be judged.  This year the challenge is to make a reversing horizontal mill engine.  Entry is free (gold coin donation accepted with gratitude).

Stirling Engine, running on heat from exhausted steam,  spinning a CD with spiral image, made by John V.



Stuart Victoria Twin, made by Malcom W



Bolton12 Beam Engine made by John V



Farmboy internal combustion engine, running on propane, made by Stuart T


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Horizontal Mill Engine running on steam, reconditioned by John V,  (GSMEE exhibit)



Atkinson Engine, running on petrol, made by Rudi V.  FIRST PRIZE.


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Stuart 5, running on steam.  Reconditioned by Rudi V.  GSMEE exhibit.


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Beam Engine “Mary”, completed by Stuart T.  THIRD PRIZE.



Mill Engine, running on steam GSMEE exhibit.


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Mill Engine running on steam.  GSMEE exhibit.


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Mill Engine, running on steam, made by Malcolm W.


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Triple expansion marine steam engine by John V.  Almost completed.  SECOND PRIZE.


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.


This is the condenser side, and the Edwards pump


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


And the top, showing some of those 429 fasteners,


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


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


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.

Compound Traction Engine

A few of my readers will have no idea what a “traction engine” is, much less a “compound traction engine”.

I have recently bought one of these machines, so here it is….


To be accurate, it is a miniature traction engine.  1/4 size.  A full size one would weigh between 14-18 tons, and a bit beyond what SWMBO would have agreed to me spending.  I see ads in the English sites offering them for between 250 and 400 thousand pounds.

This one weighs about 250kg, and it cost me a bit less than a full size one.

It is powered by lighting a coal fire in its belly, and producing steam.  The engine sits on top of the boiler.  You can see the cylinders, connecting rods, crankshaft and gears in plain view.   The steam is under a pressure of 100lbs per square inch.   It passes through the high presssure cylinder (the small one) then through the low pressure cylinder to convert the heat energy of the coal into kinetic energy of motion.   The fact that the two cylinders are powered by the same bit of steam is the reason it is called a “compound” steam engine.

Steam traction engines were the predecessors of modern diesel tractors.

As road locomotives, they pulled loads of many tons, at low speeds, from 1869 to the end of WW2.  This one was a scale model of a road loco of circa 1918.  Other types were used on farms as tractors (not terribly effectively, because of their weight), in saw mills to power the saws, and as stationary engines to power some factories.

Rather surpisingly, they are a quiet machine in comparison to more modern diesel and petrol powered ones.  They sound a bit like a steam train, puffing and chuffing along.  I fine the sound is very appealing.  I also like the exposed mechanicals.

The coal smoke is not quite so pleasant, but the Welsh steaming coal which I am using, produces very little visible smoke.   Most of the white stuff which is seen is esacaping or exhausted steam which has been cooled to become water vapour.   Steam, as I have discovered, is invisible.

So back to my traction engine….    It was made by a gentleman in Adelaide, commencing in 1984, and completed in 2016.   He also made quite a few steam train engines and traction engines over the same years.  He told me that the compound engine was difficult to make due to its complexity, and the tight squeeze of all of the components.


The square box with the brass lid is the mechanical lubricator,

The boiler is constructed from copper sheet, 4mm thick, riveted and silver soldered.    It has been tested, and certified to 100psi.  Re-certification is due, and is planned to be tested again in a couple of weeks.

I have found a few issues with the engine, and am gradually attending to those issues.   The piston rod glands, valve chest, main throttle, and starting valve were leaking steam.  Those leaks have been reduced to a level that is acceptable.

One of the big ends is noisy.  I noticed that the plans called for adjustable wedges, and they have not been used.  So at some stage I plan to make them and install them.  That should tighten up the noisy bearing.  The valve eccentric straps are a bit loose, with noticeable movement, but they should be fairly simple to tighten.

The mechanical lubricator is not working.  I have cleaned and adjusted it, but to no avail.  There does not seem to be enough movement in the driving arm to click the gear over.  Might need a re-design or a new lubricator altogether.

Some of the water supply pipes are modern flexible types and look totally wrong, so they will be replaced with rigid copper pipes.

The painted colours are appropriate for a working road machine, but I am planning a more fancy appearance with brass belly strips, polished steel cylinder covers, some pin striping, and a name plate.   Also a Fowler coat of arms.  (It is a Fowler Class R3).

Still contemplating the name.  Traction engines seem to be named after girlfriends wives or mistresses, famous people, Lords and Earls.   There is a nice movie from the 1960’s about a traction engine named “The Iron Maiden”.  Its rival was named “England Expects”, a name which resonates.   I have long been an admirer of Sir John Monash, so that is quite a possibility.  Monash was the leader of the Australian Army 1916-18, and he was so effective that the British Prime Minister of the day said that WW1 would have been a year shorter if Monash had led the allied forces.  Monash was also my university.  And we share first names.  But still considering.

So you can see that I intend to place my own stamp on this machine, and have lots of interest and fun doing it.


Boiler fire started, extractor fan on the funnel to increase the draft through the firebox, Ange, Tom and Stuart waiting for steam pressure to rise.

I attempted to upload a 2 minute video, but just too slow.  Might try later.

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…


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.


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.


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.


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.


Assembling the Triple


I got this far in assembling the model triple expansion steam engine, then lost courage and put it aside (again).  You can see the high pressure steam chest labelled “top”, the steam valve and handle, the drag links and levers for the reversing mechanism for the high pressure cylinder, and the worm and gear and control wheel for the reversing mechanism.   The reversing levers will need pinning with taper pins when the correct positions are finalised.  The short rod in the middle of the pic is temporary.  I need to make those properly.  The drag links clash with the condenser cover.  That was predicted in Bertinat’s notes.  The cover will need some material removed.  Slowly progressing, but taking frequent breathers.

The high pressure mechanisms are the most exposed, and easiest to access, and they were very tricky, and not yet compeletely installed.  I dread to consider what the intermediate pressure ones will be like, buried in the middle of the engine.   Then there is the valve timing.  Help!

SS Valve Rods

Making the new valve rods, as predicted, took me an entire day.  They required a high degree of precision, and being in stainless steel, not an easy material to machine, and quite thin and delicate, multiple stages in the machining.

But before I started on the valve rods I made myself a new spanner for the collet chuck on the CNC lathe.  I had been using an adjusting spanner, which was continually  going out of adjustment and causing angst.  The tool merchants did not have anything suitable (46mm opening, and thin profile), so I made my own.

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The 46mm spanner being cut from 6mm steel plate.

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It is a bit prettier after this photo and being painted.  The rounded jaws facilitate easy application to the collet chuck.

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Tightening the ER40 collet chuck with the new spanner.  It works very well.

So then I got on with the new valve rods.  Some end of day photos follow.

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The valve rod is the silver coloured rod.  Actually stainless steel.  This photo shows the high pressure cylinder valve and valve chest.  There are 2 other valves, one for each cylinder.  All different sizes.

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The high pressure valve chest and valve, the valve rod and guide.  On the right is the Stevenson’s link, yokes and eccentrics which control forward and reverse.  This setup is repeated for each of the 3 cylinders.  This is hooked upto the worm and gear which was shown a blog or two ago.  There are 22 components for each, not counting fasteners.

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The low pressure setup.

And thank you to those readers who responded to my whinge about likes and comments.  I will continue this blog until the triple expansion steam engine is finished, and hopefully running.  Not sure after that.

Triple Underbelly

“Underbelly” has a particular resonance for readers who know what the Yarra is and that Collingwood is a place and not a British admiral.

In the instance of my triple expansion steam engine, it refers to the bits and pieces underneath the cylinder block.  The glands which prevent steam leaks from the con rods and steam valve rods, the and valve rod guides.  These unsung heroes of the steam engine have taken 2 entire days to make.   And here they are….

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This is the cylinder block, upside down.   You can see the valve rods. the valve rod guides, the valve rod glands, the piston rods, the cross heads (unfinished), the piston rod glands,  and the cylinder bases.   Give yourself 2 marks for each correctly identified item.  The 6 hex plugs on the side are temporary, until I get around to making some cylinder drain valves.

I started to count the number of holes drilled and tapped in this view, but gave up at 100 and still not half way.  This engine better bloody work!

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Note the letter stamped into the cylinder base.  Many parts are similarly stamped.   The studs in the intermediate piston gland are temporary.

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Just a different view.

I have decided to replace the valve rods which are made of brass, with stainless steel ones. That will take an extra day, which might exceed my second, self imposed, deadline.  But if it does, well too bad.

By the way….   I am considering whether or not to continue this blog.   It does take time, and is not free.  If you read this and are not totally bored, the odd “like” would not go un-noticed.  A comment would be even better.

Reversing Gears and Handwheel

Another 2 days in the workshop.  Heaven.

I had made a worm drive and gear using an M14 x 2 tap, but it did not look the part, despite being functional.   The problem was that the threads were sharp triangular and they did not look correct.

So I made a worm drive and gear using Acme specifications.  The teeth have a chunkier squarish look.  More authentic.

I ground a lathe cutter and used it to make the worm drive in gunmetal, and another identical thread in 14mm silver steel (drill rod).   The steel thread had cutting edges formed, and when finished it was hardened by heating red hot and quenching.  After hardening, a file would not mark it.  I did not bother to anneal it, since it would be used only to cut cut brass or gunmetal.  The hardened tool was used to make a gear in gunmetal.  Unfortunately I did not take pictures of those steps.


Showing the handwheel, worm drive and gear.  the shaft is mounted in gunmetal bearings which are bolted to the columns with BA8 bolts.    The thread is Acme. 2mm pitch.  The handwheel will control forward-reverse of the triple expansion steam engine.

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In order to determine the position of the bearing bolt holes for the worm drive, I used SuperGlue to tempararily join the worm and gear.  

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When the position of the bearings was determined, the holes were drilled 1.8mm and tapped.  the taps were BA8, about 2mm diameter.  The engine is held vertically on the milling table, being cramped to a large angle plate.  The holes were drilled accurately on the mill.  The threads were made using a tapping head made by me from plans published in “Model Engineer” by Mogens Kilde.   The double parallelogram of the tapping tool keeps the tap vertical.  The tap did not break.


Close up photo of tapping the BA8 threads.  Showing the bearing, shaft, worm drive and gear.  Note the Acme thread.  The bearing is Super Glued into position to facilitate the drilling and tapping procedure.  The Super Glue will be removed later.

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The final step for today was to make the handwheel.  It is 1.5″ diameter.  The rim is 1/8″ brass and the spokes are 1/16″ brass.  I made 4 of these, with each being better than the last.  I softened the 1/8th brass before winding it around a 32mm pipe to form the rim.  The join in the rim was silver soldered.  Then the rim and the hub were drilled using a tilting indexing head on the mill.  I soft soldered the spokes on intital handwheels, but the final (and best) examples were glued with Loctite.  Loctite allows a few minutes for adjustment of the spoke lengths, whereas there is only one go with the soldering.

It is looking interesting, Yes?  And there are 3 spare handwheels.  The rest of the reversing mechanism components were made several months ago.  Almost ready to install them.

Broken Tap Removal

In a previous post I admitted to breaking a BA7 tap in the Edwards air pump of the Triple Expansion Engine, and being unable to remove it.

The hole being threaded was one of 4 to be used to hold a water pump to the air pump. It was 2.5mm diameter (i.e. pretty tiny)

I tried to grasp with pliers the fragment still protruding but it then broke below the surface.

I tried to break up the embedded tap, using a HSS punch, with partial but inadequate success.

I briefly considered drilling a hole from the other end, and punching in the reverse direction, but that would really have compromised the pump.

So I decided that the three remaining bolts would have to be enough.

A night sleeping on the problem.

Next day, with a fresh determination, I decided to attack the problem again.

I had some used carbide milling cutters 2mm diameter, and I was prepared to sacrifice one or two of them.   So I carefully set up the Edwards pump in the milling machine.


You can see the three good tapped holes.  The carbide milling cutter chomped away at the broken tap, and using gentle pressure, and ignoring the metallic screeches, the tap was broken up and most of the fragments came out.  I was prepared to sacrifice the milling bit, but it seems to have survived this insult.  The harder metal always wins.   It was probably fortunate that the tap was carbon steel and not HSS.

Somewhat surprisingly, the tapped hole was in reasonable condition, and it accepted a BA7 bolt, although I will not be aggressively tightening this one.



The bearings in the drag link are not split, because they can be slid onto the shaft.  But if there are obstructions to sliding, (such as big ends on a crankshaft), the bearings must be split, and assembled when in position on the shaft.  The bore in the intact bearings in the photo is 4mm.  The split bearings have a 5mm bore.  They are all bronze, but the split bearings have been heated then dipped in sulphuric acid so the colour has changed.


The first step in making split bearings is to machine 2 strips of metal, of identical dimensions.

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Next the strips are soldered together.


The bearing holes are drilled and reamed exactly to finished size.


The strip of soldered metals is attached to a sacrificial base plate and the outside of the bearings are machined to final size and shape.

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Holes are drilled to take the bolts which will eventually hold the halves of the bearings together.  (1.6mm holes in this case).  The bearings are then heated to melt the solder and separate the halves of the bearings.  Sulphuric acid was used to remove the carbonised crap left on the surface of the bronze by the heating torch.


The bosses around the holes was an extra machining step.


Not what you thought.

Today I made the rest of the drag links for the triple expansion steam engine, and just for fun I made one spare.

I ran out of BA10 nuts.  Ordered more.  1.6mm thread, 3mm overall diameter, 200 of them weighs nothing.  But if I drop one, that is another 25 cents down the drain, because individually they are invisible.


Drag Links for Reversing Mechanism on Triple Expansion Steam Engine

A bit more progress today.

I spent the whole day making these drag links, and I was pretty happy with the result.

Then I realised that I need 6, and I had made only 3.  (well there are 3 cylinders you see).

So you know what I will be doing tomorrow….

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The drag links are the 3 items with the bearings at the ends, and the connecting rods.  Those rods are 1.6mm diameter (1/16″ inch), and the nuts are BA 10

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I dropped 2 of the nuts.  Gone forever.

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.


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


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.


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.


Rough turning the base.


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


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


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.


The 1865 Wedlake and Dendy



My lathe is a Boxford TCL125, using Mach3.  The G code is generated using Ezilathe.

Below is a link to an oil cup from “USS Monitor”, of American civil war fame.   One of the first ironclads, powered only by steam.

(ps. The  lathe which I was converting to CNC was the subject of previous posts and is now working, but needs some guards fitted and a bit of fine tuning.)


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??



It seems months since I made any progress on the triple expansion steam engine.  It is such a complicated build, at the limits of my abilities (or maybe beyond the limits), and many  components have been partly made and put aside to be completed later, that I was unsure just where I needed to resume.

But, Xmas/Saturnalia, New year, several exhibitions, several competitions, and an intervening Stirling engine build all conspired to “force” me to put aside the difficult triple build.  Then it was just too bloody hot to venture into the workshop.  But we now have some milder weather, and I have some free time, so back into the workshop to inspect the triple and see where to resume.

I decided to do some easier components, to ease back into the build.  So I started by making some of the steam pipes,  CNC’d the flanges, and silver soldered them.  Only to discover that there was inadequate access to tighten some of the flange bolts.   So a quick redesign of the flanges to use only 2 bolts per flange, CNC’s some more flanges, removed the bad’uns, and silver soldered the new ones.   All good now, except that I need to fill some unused threaded holes in the cylinder castings, and drill and tap some new ones.


Checking the fit of the copper pipe, prior to machining and soldering the flanges


The pipes with flanges all made and ready to be fitted.  Except that these 4 hole flanges had to be replaced with 2 and 3 holers.


Inadequate clearance to fit the bolts.  So the flange was replaced with a 2 holer.


Today I made the bearings for the yokes on the Stephenson’s reversing mechanism.  These are made of gunmetal, quite small (9.5x8x4.7mm), need some precision drilling and reaming, and there are 12 of them.

After considering the “how to” options, I decided to use the recently installed 5C collet chuck on the lathe, having machined the gunmetal to fit neatly into a 3/8″ square collet.

The following pics were uploaded and the order was totally mixed up in the process.  From previous experience I know that trying to re-sort them will result in chaos and losses, so I will leave them as is.

Bolton 9 - 5

This is the final photo.   The 14 bearings (including 2 spares) are threaded onto a bright steel rod and the side decorative waist is milled.

Bolton 9 - 8

Showing one of the reversing mechanisms, with 4 new gunmetal bearings bolted into position.

Bolton 9 - 3

The square 3/8 x 3/8 lathe collet, about to accept the bar which has been accurately sized, drilled and reamed.   I used a parting tool to cut off the bearing at the correct thickness.

Bolton 9 - 4

Parting.  The blade is only 1.5mm wide.

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One of the yokes, with bearings bolted in place, and 2 loose bearings about to be fitted to the other yoke.

Bolton 9 - 2

precision drilling the bolt holes (1.8mm diameter) using the high speed spindle on the mill, at 6000 rpm.

Bolton 9 - 7

The three pairs of valve eccentrics, and reversing mechanisms.

Bolton 9 - 1

This should be the first photo.  It shows the gunmetal bar machined to size, drilled and reamed, ready to be drilled for the bolts, then parted on the lathe.

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.


Beam Engine, First Run on Live Steam

My Bolton 12 Beam engine is being exhibited at The Geelong Show in the next few days, along with other model engines from The Geelong Society of Experimental and Model Engineers (GSMEE), and many other full size antique engines.

I am particularly excited by this event, because it is an opportunity to run my beam engine for the first time on live steam.  Plus it is a really great event generally, (see blog from this time in 2014).

We set up our model engines today, in preparation.

The video below, is of my beam engine’s first run on steam.  The Vintage Machinery Society has a full size boiler to run a full size marine triple expansion marine engine, and many other steam engines, including the models in our “cage”.


The Cage in the Vintage Machinery Shed.  Not sure whether it is to keep the hordes out or the old blokes in.  (Actually, the machines become very hot when running on steam, so the cage is to keep small hands out).

The steam is at 25-30psi.  Enough to turn over the engines, which are just ticking over, not under working loads.

Click on the arrow in the video box, to see the video.

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.


More components ready to have gaskets installed


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


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


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.


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


It looks like it should do the job.


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.

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!


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


The eccentric, rod and yoke, all joined.


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


Triple Eccentrics, 4th attempt success.

The eccentrics are turned from 2 bits of brass, which are separated later.  It was a trial and error effort, mainly error.

I tried soldering the parts initially, but mistakenly used silver solder.  All was well until I tried to melt the solder, and so much heat was required that the thin brass parts were wrecked.

Next time I used Loctite, but during turning, the parts flew apart and were again damaged.

Finally, I Loctited the parts, then bolted them with the final bolts, then turned the disks.  This method worked, but the 6 disks required almost perfect dimensioning on the milling machine during drilling, then the lathe for turning and parting.  Altogether, very demanding.


Attempt one, showing the brass rod blanks which I soldered then turned, then separated, then discarded.


Final run, showing the glued and bolted brass rod, and the turned and part parted disks


Parting the disks was nerve racking, due the fine tolerances, and the eccentrically placed crankshaft hole. But it occirred without disaster


Final cosmetic facing in an appropriately small Unimat hobby lathe.


The finished eccentrics, stored on a piece of 10mm silver steel. There is less then 0.5mm between the bolt head and the machined edge.     Hooray!!!!


Today I spent a couple of hours drawing CAD elevations of the high pressure cylinder steam passages, then generating some G codes for the CNC centre drilling, drilling, and tidying up of the steam passage connection to that cylinder.

Then I spent 30 minutes or so running the programmes.

All went well.  No drill bits broken in the depths.  No break throughs of dark passages into the cylinder bore, or into the bolt holes.  Whew.

The steam passages now open into the top and base of the high pressure cylinder. Intermediate and low pressure cylinders to be done ? tomorrow.

The steam passages now open into the top and base of the high pressure cylinder.
Intermediate and low pressure cylinders to be done ? tomorrow.

This is the drilling setup. I used a sine vice, sitting on gauge blocks, to produce an exactly 5 degree angle, to avoid the cylinder bore and the bolt holes.  The sine vice was held in the milling vice.

This is the drilling setup.
I used a sine vice, sitting on gauge blocks, to produce an exactly 5 degree angle, to avoid the cylinder bore and the bolt holes. The sine vice was held in the milling vice.


I am waiting for some new 2mm milling cutters to arrive before I tackle the steam passages in the triple, so I decided to apply some finishing touches to the Bolton 7 boiler.

The aluminium castings on the ends were removed, and painted with a high temperature engine paint.  While the boiler was in pieces I connected the steam exhaust pipe from the engine to the boiler chimney.


The before shot. The engine and its boiler are sitting on a mantelpiece in our living room.


It looks better with the ends painted matt black, yes? I suppose that I should have also painted the brass sides and copper boiler, but I really like those metal colours. 

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.


In the previous post I described my attempt at silver soldering the condenser unit.

The 29 joins on one end were quite water tight, but the other end leaked like a sieve.

I decided to try to fix the leaky end, by doing the following….

1. I shortened the copper tubes which were protruding more on the leaky end, thinking that the deep narrow spaces between the tubes might not have become hot enough during the soldering.

2. I used a Dremel to enlarge the spaces between the copper tubes.

3. I watered down the flux to make it more runny, in an attempt to get it into the narrow spaces.

4. I used a larger oxy-acetylene tip, to deliver more heat onto the job.  I think that maybe (as per reader John’s suggestion) I was getting intense heat at the soldering point, but maybe not enough into the base metal of the condenser.  The condenser is a thick brass, heavy object, and maybe, maybe it just was not hot enough.  With the bigger heat delivery, it did show the dull red heat which is recommended for silver soldering.  Also, I used a lower silver content rod (45%), again reader John’s suggestion, because it melts at lower temperature, and is less viscous, than the higher silver content rods.  Thanks John!

End result….

The condenser unit, after today's soldering fix.  Note: there are no air bubbles rising!  It is air-water tight, at atmospheric pressure.  That is enough, because it is a low pressure unit when in use.

The condenser unit, after today’s soldering fix. Note: there are no air bubbles rising! It is air-water tight, at atmospheric pressure, which is adequate, because it is a low pressure unit.IMG_2766 (1)Then I glued the end covers onto the unit, using Loctite, in preparation for the next step, which is drilling and tapping the holes for the BA7 bolts which will hold the end covers in place.

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.


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.


The Bolton 9 triple expansion steam engine build has stalled, and it is all due to achluophobia

Achluophobia, in case you are not fully aware of the term, is fear of dark places.

The next step in the build, is to drill or mill  the steam passages (the dark places).

These passages are slots less than 2mm wide, and up to 14mm deep.  The plans call for 6 of these deep, narrow, dark slots to be made in the cylinder blocks, upon which many many hours of work have already been lavished.   In addition, the slots have a 90 degree bend in the depths.  And that bend is only 2mm away from the cylinder.

The thought of a broken drill bit, or milling cutter, at those depths in the cylinder blocks, fills me with apprehension.

So I have done what I usually do when facing a difficult task with potentially disastrous consequences….  nothing.

I am waiting, thinking, and hoping that some thought bubble will pop, and give me the answer as to how to accomplish the task with some certainty of success.

Any suggestions would be welcome.

Maybe it is not achluophobia.  maybe it is atychiphobia.

IMG_2742 IMG_2743

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

The triple expansion steam engine now has a valve in each cylinder head.  They are manually controlled, not automatic, and I guess that is the reason they are called “false” valves.

The body of each valve was shaped in the CNC lathe, using software called “Ezilathe”.   There is a lot of good software for CNC milling machines, particularly Mach 3, but not much for lathes, at least for the non professional user.  “Ezilathe” is a free program (currently), works brilliantly, and was written by my friend Stuart.  It has an inbuilt simple CAD program, automatically generates G codes, and has a G code editor.   It also has a terrific, easy to use threading facility. It has an accurate simulator, and a tool editor.   Do a search on CNC Zone to download a copy.


The “false valves” in the cylinder heads.

One problem which I experienced with these valves was that the thread which secures the valves to the heads, stopped short of the expanded hexagon part by about 1mm, and I needed to turn a very narrow groove in the stem to allow the hexagon to screw down hard on the head.  I do not have a lathe narrow grooving tool with enough reach to do this, so the following photo shows how it was done…

A broken slitting blade, held in a shop made holder.  Normally I use it under power, but in this case, the part was held fairly tenuously, so I turned the lathe spindle by hand.  It worked perfectly!

A broken slitting blade, held in a shop made holder. Normally I use it under power, but in this case, the part was held fairly tenuously, so I turned the lathe spindle by hand. It worked perfectly!

Just for interest. This tiny engine was made by model engineer Peter B on a 3D printer.  It is about the size of a matchbox.

Just for interest.
This tiny engine was made by model engineer Peter B on a 3D printer. It is about the size of a matchbox.

Piston rods for triple, and some engraving.

A good aspect of retirement is that the there is time for learning a new skill.  (Time, but not necessarily brain power.)

A case in point for me is the trials and errors of engraving.

In previous posts I outlined the steps in setting up the engraving spindle on my CNC mill, and the mechanical issues now seem to be fixed.

But getting lettering which is crisp, clear and attractive, in brass is a bit more complicated than, say, using a computer printer.

Issues:  Selection of cutter (angle of point, flat area or not),Spindle speed, feed rate, depth of cut, coolant or not, and selection of font are all variables to consider, and try out.  Also whether the letters are raised or excavated.

Each brass plate (65 x 32mm) takes 15-30 minutes to engrave, plus set up time.  So I have spent many hours in the last week trying various combinations and permutations.

Here are some pics of early results.

Finger for scale, and for privacy of the recipient. The quality is OK, but not quite as sharp as I would like.

Finger for scale, and for privacy of the recipient.
The quality is OK, but not quite as sharp as I would like.  Lettering is 0.75mm deep.  Perhaps a little too deep.

Label for a steam engine.  It is crowded and fussy, but I will probably use it until I get around to making a better one.

Label for a steam engine. It is crowded and fussy, but I will probably use it until I get around to making a better one.

Some progress on the triple expansion steam engine, but not much to show visually.  The pistons and piston rods have been made and fitted.   The piston rods screw into the pistons, and then have a lock nut on top.  The lock nut will be loctited at the final assembly.

I had an issue with the piston rods not being exactly concentric with the pistons, probably due to inaccuracy of my lathe chuck.  So I skimmed the piston surface while holding  the piston rod in the most accurate chuck in my workshop, which is the engraving spindle.  See the photo.

The pistons, piston rods and viton rings.

The pistons, piston rods and viton rings.

Turning pistons on a vertical mill. Not the clearest photo. It shows the high pressure piston (the smallest one) held in the collet chuck of the engraving head, being skimmed with a lathe tool which is held in the milling vise. It worked very well indeed!

Turning pistons on a vertical mill.
Not the clearest photo.
It shows the high pressure piston (the smallest one) held in the collet chuck of the engraving head, being skimmed with a lathe tool which is held in the milling vise.
It worked very well indeed!

Pistons for triple expansion steam engine.

Yesterday I turned the pistons for the steam engine.

The plans called for the pistons to be made in 2 halves, and the rings to be cast iron.

But the plans also showed the cylinders were cast iron, and my castings were all gunmetal.

So with gunmetal cylinders, I decided that iron rings were not appropriate.

I have used graphite impregnated packing for other steam engines, but after investigating the use of Viton O rings, I have decided to use them.

Viton rings are easy to install, cheap, easy to replace, and apparently work well.  They would not be used in an engine doing serious work, but my steam engines are more for display and interest and education, and will do few hours under steam.

Also Viton rings are quite small.  So if I decide later on that I want to change the Viton to packing or something else, I will simply turn larger grooves in the pistons to accept the alternative.

The pistons with Viton rings .

The pistons with Viton rings .


A day out of the workshop for looking after my grandson, and watching my daughters husbands eldest son from his first marriage playing football, and cheering him on for kicking 3 goals in the last quarter….!!

But back into the workshop today.

First I bored the big end bearings.


Bored on the mill, not CNC for a change. After some fiddling to get the measurement correct on the first big end, the next two took only a few moments.

Then some finishing turning and polishing for the con rods, and a decorative groove.

Then bored and reamed the the crossheads for gudgeon pins.  For once, the 3 cylinders were the same, so measure the first then quickly repeat the process for the next two.

Then, for a bit of fun, I assembled everything done so far.


The crankshaft, con rods, crossheads, gudgeon pins.  The big cylinder in the foreground is a handle which I use to turn over the crankshaft manually or in the lathe.  It is also a threading handle (home made).


Close up of the engine guts.


The whole engine, so far. It is quite exciting to see it coming together. SWMBO is not impressed with it sitting on the kitchen table.

Next on my list, the pistons and piston rods.   Big decision.   Rings.   Cast iron or packing.

ps.  Neither.  Cast iron rings in gunmetal cylinders not a good idea.  Gunmetal would wear excessively.  Graphite impregnated packing would be OK, but I am probably going to use Viton O rings.  Easy to install, fairly inexpensive, and quite suitable in an engine which is unlikely to see any serious work.


With the crankshaft installed and the main bearings snugged down, I tried to turn the crankshaft by hand.  It should have felt tight and smooth and firm, but it was, like the curate’s egg, only good in parts.  There were tight spots, and even when the mains were loosened, there were tight spots.

So I tried turning the crankshaft by hand some more, thinking that the high spots would wear down.  But with only minimal improvement.   Clearly some more aggressive lapping would be required.

I have some diamond lapping paste, in various grades, and I have no doubt that it would have been effective at taking off the high spots.  The problem is that the diamond dust can impregnate the softer metal in the bearing ie. the gunmetal, and remain there, continuing to score and wear the bearings for ever.

A colleague suggested using a grinding paste containing a much softer grinding material.  Toothpaste was mentioned, along with some kitchen scouring cleaners.  I could not find any such things in my workshop, so off to the supermarket I went.

SWMBO claims that I have no idea about supermarket shopping, and on this occasion, she was correct.  Confronted by dozens if not hundreds of cleaning agents, I was totally bewildered by the array of options.  So I did what any self respecting red blooded Aussie male would do…  I rang her and asked which brand to buy.

This is what I bought…..

Gumption kitchen laundry cleaner

Gumption bathroom kitchen laundry cleaner.

I applied the Gumption to the bearings…


Using a small brush which any gynaecologist will recognise..

And set up the crasnkshaft – base – bearings in the lathe …..


And ran the lathe at 40 rpm for a few minutes.  The temporary nature of the abrasive in the cleaner was evident by the scratching noise which stopped after a few revolutions.  The 5hp lathe motor was required to overcome the friction caused by the paste.   Very quickly, the resistance to turning disappeared, and it was obvious that the Gumption was working. (later, when I used the same method on the big end bearings, I found that it was quicker and easier to turn the motor by hand. Huge force was not necessary. And it took only 5-10 revolutions to do the job).

After grinding with Gumption, the bearings were disassembled so the paste could be cleaned off.

After grinding with Gumption, the bearings were disassembled so the paste could be cleaned off.  The high spots which were removed were quite visible.

After cleaning off the remains of the paste, and assembling the crankshaft, I retested the crankshaft & bearings. An amazing difference! Now it was smooth, and I was able to turn the shaft by hand, even with the bearing nuts tightened quite substantially. I might repeat the process to improve things even more.

Very impressed with Gumption. Great stuff.

Con rods for triple -3 finished!

The finished con rods.  I wont bore you with the photos of milling the wishbone slots.

The finished con rods. I wont bore you with the photos of milling the wishbone slots.

The crossheads have been dimensioned, and the big end bearings machined, and glued with Loctite in prpeatyaration (sorry, too many reds after dinner), preparation for accurate boring.

The crossheads have been dimensioned, and the big end bearings machined, and glued with Loctite in prpeatyaration (sorry, too many reds after dinner), preparation for accurate boring.

The big end bearings, machined, and glued, ready for accurate boring.  Is that what I am doing to you???

The big end bearings, machined, and glued, ready for accurate boring. Is that what I am doing to you???


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.


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.


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.


A bit clearer with the swarf swept away!


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


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




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…


There are three connecting rods, and despite the different cylinder sizes, the 3 rods are identical. Due to the fact that the stroke for each cylinder is identical. It is only the bore which differs.

The castings for the con rods did not permit them to be held in a lathe chuck, even an independant 4 jaw. So I drilled centres, and held them between centres for turning the shafts.


The con rod castings, after the initial tidy up on the belt and disk sander.

The con rod castings, after the initial tidy up on the belt and disk sander.


The drilled centres, and rather rough centre lines.


Each main bearing consists of 2 gunmetal halves which fit into a slot in the base, and a cap which bolts to the base.  There are 6 of these.

I machined the gunmetal castings, and made the caps.

Before I finished the machining or drilled the holes for the bolts, my phase changer failed, so I finished the job on my (single phase) drill press. Not ideal but adequate.

The Phase Changer has failed at least once every year since I bought it 5-6 years ago.  It is the least reliable machine in my workshop.  Repairs to it seem to take at least 3-4 weeks on each occasion, which is frustrating.  I will borrow a 3 phase diesel generator to keep the workshop in action while waiting (again) for the repairs.

One of the 6 main bearings and caps.  The hole has been roughed out, ready for accurate boring

One of the 6 main bearings and caps. The hole has been roughed out, ready for accurate boring

The 6 main bearings sitting in their slots.  The hold down bolts are ready to be installed.  The bearing surfaces will be bored when I have some 3 phase power again.

The 6 main bearings sitting in their slots. The hold down bolts are ready to be installed. The bearing surfaces will be bored when I have some 3 phase power again.

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.


It is not perfect, but it will do.,

Today I removed the support blocks (heated with a gas torch to soften the Loctite) cleaned up the sharp edges, shaped the flanges, and polished it.

Next on the list is to make and fit the main bearings.  Thank goodness they are made from gunmetal.  There are 6 of them, and each has 3 components to be shaped and fitted.


The stainless steel has a nice lustre, but it is difficult to machine.

CRANKSHAFT, almost finished

The crankshaft is almost finished! It is not perfect, and I am considering making another one. But for a first effort (at a crankshaft machined from solid), it is not too bad.   Actually, it was the second effort.  The first one was binned due to a 3mm eror.

I made the job much more difficult by using stainless steel as the material. Stainless is hard, and must be machined with carbide tooling.  Problems with chatter and tools blunting.  The big ends needed thin tools with a lot of overhang. After my initial unsuccessful effort, a friend suggested the use of a Gibraltar toolpost, which certainly reduced the chatter. (thanks David M).


Turning the big end bearings, using a carbide parting tool held in “Gibraltar” tool post. Actually, it is an “Uluru” toolpost. Whatever the name, it worked better than the normal quick change toolpost on my lathe.

After an estimated further 12 hours of turning and milling, the crankshaft is almost finished.


The support blocks glued with Loctite to support the main shaft, are still in place.

 Ahuman hand for scale.  Refer back to the original lump of 50.8,, diameter stainless steel pics to see how much material has been removed, leaving the crankshaft.  I have a large amount of razor wire to dispose of, and many cuts on my hands and face.  This is mongrel material to machine and I hope to never use it again.  At least my crankshaft should not rust.

A human hand for scale. Refer back to the original photos to see the lump of 50.8,, diameter stainless steel  to see how much material has been removed, leaving the crankshaft. I have a large amount of razor wire to dispose of, and many cuts on my hands and face. This is mongrel material to machine and I hope to never use it again. At least my crankshaft should not rust.


This is a very nice animation and summary of the triple expansion engines and steam turbine on the Titanic.

Note that the triple expansion engines  have 4 cylinders.  There are 2 low pressure cylinders.

Be prepared to hit the pause button on some of the old photos.

More Crankshaft. Roughed on mill, finished on lathe.

This is the first big end bearing.  The bearing surface was roughed out on the mill (held between centres using the dividing head), then the excess  around the flanges was removed on the mill (with the workpiece held in the milling vice),  then the bearing surface was finished in the lathe.

This is the first big end bearing. The bearing surface was roughed out on the mill (held between centres using the dividing head), then the excess around the flanges was removed on the mill (with the workpiece held in the milling vice), then the bearing surface was finished in the lathe.   There is a crankshaft buried in that lump of steel.  I just have to remove all of the bits which are not crankshaft.  (apologies to Michelangelo).

Making a start on the second big end. There is a block of steel loctited in the first big end so it is not bent when the workpiece is compressed between centres while the other big ends are machined. The second big end is yet to be finished on the lathe.

Making a start on the second big end.
There is a block of steel loctited in the first big end so it is not bent when the workpiece is compressed between centres while the other big ends are machined.
The second big end is yet to be finished on the lathe.


A slightly different view showing the block glued into the first machined big end, and the almost finished second big end. This is the milling machine setup.

CRANKSHAFT- using the mill instead of lathe

My first attempt at making a crankshaft for the triple expansion steam engine involved turning the workpiece between centres.

It worked in a fashion, but only at 200rpm.  At that speed, not  great finish.  And frankly it was scary and hairy!

Then I discovered that I had made a 3mm mistake in the position of the middle big end bearing, so it all had to be done again.


The first method of making the crankshaft. Slow, not a great finish, and fairly hairy, despite the 2 tonne lathe.

So today, with some new steel, I decided to use the vertical mill instead of lathe. Actually, I turned the cylinder to size on the lathe, after drilling the centres on the mill. I tried to turn the big ends on the lathe, (eccentric turning, using counterweights this time) but I was still not happy with the result from the intermittent turning.
So I tried a different method, using the vertical mill, and rotary table, set up as in the photos.


Setup on the vertical mill. The rotary table was turned by hand… rather tedious. The 8mm end mill was run at 1600 rpm, taking off 0.5mm on each revolution. A slow process, but it felt safe, and the finish was excellent.


The rotary table setup.


Only 10mm of material remains, for the big end bearing. Before excavating the material for the next 2 big ends, I will glue (Loctite) blocks into the gaps to provide support. The mains will be turned or milled last. I might still finish the bearings on the lathe. Not yet decided. Watch this space,

After my initial problems with making the crankshaft, I asked and obtained advice from my Model Engineering Club colleagues. That resulted in the decision to machine the big ends first (thanks Stuart) and counterweight the turning when doing offset turning (thanks Malcolm). Also thanks to Peter V, for double checking my measurements this time, and jollying me along.

Still a lot to go to finish the crankshaft, but I can see that this method will work.  I might motorise the rotary table before I start any more of the 8 remaining bearings.

p.s. 7 December 2019 (4+ years later)  I did eventually motorise the rotary table, with a stepper motor, and it is CNC controlled, along with the XYZ axes on the mill, by Mach 3.   The triple expansion engine has been running on steam for over a year, and is virtually finished except for some optional small fittings (like cylinder waste drains, builder’s label).

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


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.


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…

WHEEL BALANCER- another home made tool

This is a jig for balancing wheels for steam engines, grinding wheels etc.

The jig has 3 adjustable pointed bolt legs for levelling.

The top of the jig was flattened on a surface grinder, then the silver steel bars were bolted (without tension).

If the wheel is perfectly balanced it will not roll.


Wheel balancer, with steam engine wheel yet to be finished.

Bolton 12 Beam Engine Under Steam

A YouTube video of a Bolton 12 running under steam.  Not mine, (the workshop is much too tidy) but definitely inspires me to hook mine up to a boiler.


The time which I have had spare in the past few days has been spent tidying up the workshop,  sorting tools and putting them away.  Today I spent a few hours making a start on the intermediate and low pressure steam chests.

Roughed them out and CNC’d a boss on the bottom of each chest.  Then roughed out the steam chest covers.

This is the progress to date.


So far I have drilled, tapped and inserted ~180 BA7 screws and studs. And there are a lot more to go. The steam chests and covers are sitting on the base.

Attaching the cylinder block bases to the cylinder blocks was tricky.  I drilled the holes with the bases glued to the blocks using Loctite, and then tapped the holes and inserted the screws.  I will apply some heat to break down the Loctite.

It is quite difficult to insert the screws to the underside of the block.  Many are quite inaccessible.  There have been multiple tear downs of the model, with many more to go, so only a small number of screws are currently inserted.  I will have to work out an order of assembly, to make the assembly process as logical and easy as possible.

I am starting to consider which method I will use to make the crankshaft.  It has 6 main bearings, 3 big end bearings, and locations for 3 valve eccentrics and an oil pump.  It is quite complex.  Fabricate or turn from the solid.  I am tending to the latter, but we will see.


The 56 bolts which attach the cylinder heads, were installed today.

First, the heads were bolted into position with a jig.


The work is held in position on the milling machine table, using 4 hold downs, and 2 T slot locating fixtures. The jig also helps to secure the work to the table.

The jig fits into the milling machine T slot, and the bolts are exactly positioned in the centre of the heads.

The bolts hold the heads in place while the centre drilling, through drilling and thread tapping takes place.

That is 4 processes for each of the 56 holes.  Even semi automating the process using CNC, it took 6 hours, including setting up, making the jig, and finally installing the bolts.


Drilling the relief holes in the heads, after preliminary centre drilling. Those holes are only 2.5mm diameter, and 12mm deep. Despite the tiny drill size there were no breakages. The drill was set at 2500 rpm, feed rate 50mm per minute, and with pecks set at 2mm. A cutting lubricant was used.


The head bolts in place. The bolts are BA7, which is pretty tiny, but they look the part, yes? The highest “density” of bolts is on the smallest cylinder head, which is on the high pressure cylinder. The threaded holes in the centre of the heads are for the pressure relief valves.

I have left the set up intact on the milling machine, until I am sure that there are no further processes I can perform with the block in this position.



Click on the link to watch a movie-documentary from the 1930’s.
If you are a steam head, you will love it.

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.


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


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.


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


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.


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.


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.

Buying Tools and other stuff at a swap meet.

Today I drove with a friend to Ballarat, Victoria, Australia to the biggest swap meet in the Southern hemisphere, maybe the biggest in the known universe.

It is located on an aerodrome in country Victoria.  Approx 2500 stall holders selling stuff from shed cleanouts, factory close downs, farm sales, and some commercial sellers.

A lot of the stuff on sale seems to be total junk, with the vendors sitting around enjoying the sunshine, the conversations, the beer and barbeques.  A lot of them stay in tents and caravans on site.  But there are many gems and bargains, and that is the reason I find myself drawn back to the event, annually for the past 4 years.

The atmosphere and mood is relaxed and pleasant.  A fair bit of good natured haggling and bargaining goes on.

You do have to keep an eye out for kids on bikes whizzing about.  It is supposed to be a car free zone, but I noted far too many vehicles driving about raising dust.  The organisers need to get on top of that issue.

I was also a bit peeved to have to pay $3:50 each for a small plastic bottle of water.  It was a hot day, and several of these were required.  The price was feasible because there were no other visible sources of drinking water.

But I was very happy with my purchases.  Photos following.


Hats, sunscreen, and fluids essential. 34 degrees C.


Amazing eclectic variety of stuff on sale.


I estimate that I walked 10km checking out about 50% of the sites. Too many to see in one day.



A heavy duty, well constructed welding earth clamp for $10.


Some bronze manganese welding rods for $15. I will check their machineability.


A miniature internal threading tool with inserts. Expensive at $130, but good value.


A 1″ m3 step drill (new), and a used but good condition 1.5″ M4 drill bit. $30 total. Great value.


2 cobalt 9/16″ drill bits for $6. Only one size available. Amazing low price.


A pair of razor sharp Japanese wood chisels. Pricey at $70, but the conversation I had with the Japanese cabinet maker who was selling them, was priceless. The handles are rosewood and oak. The steel is laminated, similar to samurai swords. I look forward to trying these.


A Mamod steam tractor. It seems to be in reasonable condition, and complete. I told SWMBO that it is a present for a grandson when he is a bit older (2 years old now), but we will see. I really like it myself. Is 64 too old to be playing with toys? Was said to be in working condition, but I expect that some renovation will required.  Price not for disclosure to SWMBO.


This was the most interesting purchase. 3 “Model Engineer and Amateur Electrician” magazines from Sep to Dec 1900. $5 each. The articles about “using electricity in the workshop” were sobering. It was nice to see articles about lathes apart from Myford discussed. (Drummond most common). Not sure where these magazines will end up. They should be on display, or in a museum.


Today I assembled the base, columns and Jig, intending to mill a flat top to the whole assembly.

To my surprise and dismay, it was apparent that one of the columns was one mm out of position.  Dont know how that happened.  A typo in the CAD drawing or CNC program?  It could not be a zeroing issue, because all 3 columns on that side would be out of position.

What to do?

I decided to turn the 2.5mm holes in the column base into slots 3.5mm long.  The bolting position on the jig was exactly correct, so I used that to zero the position, found a 2.5mm end mill, and gingerly milled the slot. holding the column upside down in the milling vice.

Fortunately, that seems to have worked.  The columns are now all correctly located.   The tops of the columns are the crucial plane and position, and they seem good.  I doubt that the slots will be an issue in the finished engine.  They are invisible under the column feet.  If necessary, I will make a couple of locating pins and drill them in position right through the base from underneath.  I doubt that will be required.

After that, I did take a milling skim off the column tops, to create a dead flat plane, to which to bolt the cylinder bases, when I have made them.

Not tomorrow though.  I am off to Ballarat Victoria to a swap meet on the aerodrome.  In previous years there have been approximately a thousand stalls.  Some are shed clean outs, some commercial vendors and dealers, and lots of ancient cars and machinery and parts.  The best stalls are the ones selling used tools.  I seem to come home after each meet with a heavy pack full of tools and materials, and a lighter wallet.  But it is always interesting and fun.

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.


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.


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?


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.


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.

108 Accurate holes. CNC again.

The triple expansion engine legs will be bolted to the base, with 9 bolts each.  That is 54 holes which needed to be precisely drilled so the columns are accurately positioned.  Each one of those holes needs to have a mating hole made in the base.  The base hole will be threaded to accept a stud.

Normally one gets accurately mated holes by drilling through both objects simultaneously, but that was not possible in this situation due to obstruction from the columns themselves.

So the solution??   CNC of course!

The hole positions were known from the CAD drawings, and were entered into the CAM program.  The resulting file was too big for my old CNC mill (1997 model), so I attempted to drip feed the information as the machining operation was taking place, but without success.  Several phone calls to my expert friend Stuart did not resolve the problem, so Stuart kindly came to suss it out.    A couple of hours later he had the drip feeding working as a result of a serendipitous error.

We knew that the largish file needed to be drip fed into the CNC mill, but it eventuated that we had to try to enter it directly, and produce an error message first, before drip feeding it.  A bizarre system, originating from the land of Manuel of Faulty Towers.


A test run in scrap wood.


Heart in mouth, center drilling in progress


And  2.5mm through  drilling


And the mirror image holes in the base. 2.05mm diameter, ready for BA7 threading. See how the holes line up exactly with the marking lines.  Now to make 54 BA7 studs.

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.


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.

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.

IMG_2383 IMG_2384



90% setup time, 10% machining.

The columns are tapered on all faces, so are difficult to hold, and difficult to measure.

I did a CAD drawing, to measure the taper angles, and to calculate some extra dimensions.

Then, in order to hold the castings in the milling vice, I made some accurate wedges at the appropriate angles (3 and 12 degrees) in wood and aluminium.

I actually progressed a bit further than the photos show, even roughing out the condensing tank.



The aluminium wedges have a 12 degree taper. The top wedge is sitting on a 10 degree and a 2 degree precision taper, giving an accurate 12 degree slope for milling. I made 2 such wedges, each 100mm long.


Unmachined casting on right. Partly machined on left. Quite difficult to set up, despite the setp up blocks at the appropriate angles.


Wimshurst Electrostatic Generator, made by Peter Bodman.  Creates sparks up to 100mm long, which drill minute holes in interposed paper sheets.  No-one volunteered to ry it with a hand.

Wimshurst Electrostatic Generator, made by Peter Bodman. Creates sparks up to 100mm long, which drill minute holes in interposed paper sheets. No-one volunteered to try it with their own hand.


Vacuum engine made by Peter Bodman.


Awesome model of pre-dreadnaught ship circa 1902 “Preussen” made by Walter. It is approx 1 meter long, weighs 16kg, and is radio controlled. The 28cm gun turrets are also radio controlled, but do not (as far as I know) actually fire.  To the right is a model of Columbus’s “Santa Maria”.


The detail in the model has to be seen to be believed.  Every plank of the decking is individually made and fitted.


Walter showed us the inside construction, engines, and electronics. The model was made from a few old photographs, and simple side and top elevations.


Hull with the superstructure removed


A very old pressure gauge, restored so that the workings are displayed, to reveal how it works. By Stuart.


This model boat was made by 8 year old Niall, with some supervision from his Dad, William. The gun is actually a radio controlled water cannon which fires up to 3 meters, to the wet surprise of some spectators. Niall and William both had a fantastic experience with this project.


William with some of the wonderful boat and ship models which he (and Niall) have made in recent years.


A model working ship steam engine and boiler, by Walter. Twin cylinder, double acting cylinders. This should be jewellery, worn around the neck of a beautiful woman.  OK, that is a little over the top, but you get the idea



Close up of the marine engine by Walter


Les Madden with his partly completed Atkinson Differential Engine Model, originally patented in 1887. The wooden model on the left was built by Les in attempt to figure out how it worked! He made the wooden parts to have aluminium castings made.


Les Madden’s Differential engine.

18 radial cylinder aero engine, by John Ramm.  The hand carved propeller is approx 600mm long.

18 radial cylinder aero engine, by John Ramm. The hand carved propeller is approx 600mm long.


Detail of the aero engine. John showed 3 aero engines. He is currently making a 12 cylinder Spitfire Merlin engine which he will have finished by the time of the 2015 exhibition.


Stuart Tankard’s prize winning hit and miss engine, was running throughout the exhibition. 17.7cc, 4 stroke, 4:1 compression, running on gas.


Close up detail of the hit and miss engine. A standard the rest of us can aim for.


A vertical boiler made by Stuart Tankard

Thomas Lord in the cabin of his steam truck, giving some driving tips to Niall

Thomas Lord in the cabin of his steam truck, giving some driving tips to Niall

These photos are just a small fraction of the many model engines, ships, trains, tools and other projects created and displayed by members and friends of GSMEE.


Steam truck, built by Thomas Lord.  See following videos

Steam truck, built by Thomas Lord. See following videos

The GSMEE held its annual exhibition of projects by members and friends, on the weekend of 15-16 November 2014, at Osborne House, Swinburne Ave, Geelong North.
I will post some pictures and videos of some of the superb model engines, boats, ships, tools, aero engines, and even a full size road legal registered steam truck, pictured above. Due to the size of the files and the crap Internet connection available here, I will spread the post over several days.

To continue with the incredible steam truck, made over the past decade by Tom Lord, see the following videos.  (sorry, no luck with the upload. I will try again tomorrow)


Beam Engine Driving Wheel 2

The aluminium disk was drilled then reamed to 19.05mm (3/4")

The aluminium disk was drilled then reamed to 19.05mm (3/4″)


Then a shaft was pressed into the disk. The shaft is the same as the shaft on the beam engine, in fact it is from the same stock. It was centre drilled at the ends in preparation for turning between centres, and shaping the driving wheel.   This should result in a wheel which runs true and does not wobble when installed onto the beam engine. 

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

Today I drilled and tapped the holes for the bolts which secure the crankshaft main bearings.  I had accurately marked the bearing mounts  in the previous session (see previous photos), and calculated and recorded the DRO (digital read out) position for each hole.  So going back to that position for each step in the process was easy and quick.  The steps today were centre drilling, drilling the 3.3mm holes, and tapping the 4mm threads to a depth of 20mm.

Centre drilling is done with a centre drill bit in an accurate chuck in the milling machine.  Centre drill bits are inflexible and will not wander over the work like an ordinary twist drill bit,  The centre drilled hole is deep enough to create a chamfered edge to the hole.  All 12 holes are drilled with the centre bit, then all 12 drilled with the 3.3 mm bit, then all 12 are threaded.  The DRO positions the work within 0.005mm each time, and the repositioning is very fast, much faster than going to a position doing all 3 processes, changing the bit for each one, then moving to the next position.

The threading was done with a Tapmatic 30 tapping head in my milling machine.  See photo.  This takes about 10 minutes to set up, but the tapping process for the 12 holes then took about 5 minutes.  I use Rapid Tap lubricant for tapping, even in brass.  I guess that manually tapping the holes would have taken about the same time, but it was so satisfying to see the Tapmatic do its stuff.  I use the Tapmatic for any tapping job involving more than about 8-10 holes.  Fewer than that it is quicker to do them manually.  The Tapmatic has a adjustable clutch.  I have never broken a tap in the job using this machine.

Incidentally, I have decided to use nuts and bolts and screws and studs in preference to metric cap screws for this model.  The appearance wins out over practical expediency.  So why the metric threads for this job today?  The specified thread was 5/32″ which is 3.96mm, so I decided to go with the 4mm metric, for which I have the tools already.


Tapping the main bearing blocks using the Tapmatic and Tap Magic.

Tapping the main bearing blocks using the Tapmatic and Rapid Tap.


I had almost 8 hours in the workshop today.  The base plate is progressing.


Sheet 1 of 3

Sheet 1 of 3

Milling the main bearing housing slots

Milling the main bearing housing slots.  Using a 14mm HSS end cutter.  Ended up blunt.  There must be some embedded casting sand still

Then I spent an hour or so painting the machined surfaces with marking blue, and marking reference points and edges.

Using a Knu vice to cramp the base plate to and angle plate, and a height gauge to mark the reference lines

Using a Knu vice to cramp the base plate to and angle plate, and a height gauge to mark the reference lines

Top view of the marking out lines

Top view of the marking out lines

After machining the main bearing housings, the big end slots and the eccentric slots.

After machining the main bearing housings, the big end slots and the eccentric slots.


Reducing the width of the aluminium plate to 140mm, so it will fit into my milling vice

Reducing the width of the aluminium plate to 140mm, so it will fit into my milling vice.  The plate is clamped to an angle plate.

Squaring the ends.

Squaring the ends.


The base plate bolted to the aluminium plate. Care was taken to fix the brass base centrally and parallel to the aluminium. The fixing bolts are 3mm cap screws, and the holes through the brass plate are 3mm, so even if the brass base is removed, it will go back on in exactly the same position.


I finished the day by making a spur gear for my brother’s lathe.


The gear attached to the shaft using Loctite.  If the Loctite is inadequate, the gear can be pinned to the shaft.   In the post tomorrow, to Townsville QLD.

The gear attached to the shaft using Loctite. If the Loctite is inadequate, the gear can be pinned to the shaft. In the post tomorrow, to Townsville QLD.  The photo shows why metalworking is an unsuitable hobby for a gynaecologist.


The base casting.

The base casting.

The base of the base, machined flat

The base of the base, machined flat

The base, with 6 pillar mounting areas machined parallel & coplanar, and the crankshaft mounting blocks after an initial skimming.

The base, with 6 pillar mounting areas machined parallel & coplanar, and the crankshaft mounting blocks after an initial skimming.  Slots for big ends roughed out.  2 hour first machining session.  2998 hours to go?

After carefully examining the base casting, and scrutinising the plans to discover all of the dimensions of the base, I commenced machining on my King Rich mill (Bridgeport clone, NT40 with DRO, an excellent machine). Since the base dimensions are scattered over 3 pages of very complex plans, and I am still relatively unfamiliar with them, I am approaching the machining with great caution. At this stage I am aiming to create some flat and coplanar surfaces, with a margin of material remaining, so I can hold the base flat, without rocking, roughing out the shape, and leaving finishing to dimensions at a later date. I intend to attach the base to a rectangular piece of aluminium, so the aluminium can be clamped or held in a vice, rather than risking damaging the brass casting.


Today I received a 16.6kg package by courier. It was too heavy for the regular post.  It contained the castings for the model triple expansion steam engine, which I am hoping to build in the next year or so.  I am told that on average this model takes 3000 hours to complete.  That is a scary thought.  Almost unbelievable.  But when I calculate how many hours went into the much simpler single cylinder beam engine (maybe 600-800), I guess that it is not an unrealistic estimate.  Just as well that I am close to retirement age.

The castings were made in NSW Australia, and supplied by Kelly Mayberry at EJ Winter.

All carefully wrapped

All carefully wrapped

The castings are all brass, gunmetal, or bronze

The castings are all brass or gunmetal.  There must be at least 100 of them.

Looks like the condensor chamber, as part of the engine frame.

Looks like the condensor chamber, as part of the engine frame.

The base.

The base.

A large chunk of brass

A large chunk of brass, the intermediate and low pressure cylinders.

The castings appear to be free of holes or defects

The castings appear to be free of holes or defects


Laurie Braybrook

A well known exhibitor and his eclectic display of steam valves.  A small part of the Model Engineering display is visible at back.

The annual “Royal Geelong Show” was held last weekend.  It has been held for the past 159 years.  Farmers exhibit their best cattle, pigs, sheep, alpacas etc and produce, there are various equestrian events, tractor pulls, Lanz bulldog races, dog breed competitions, and all of the side shows, show bags, and amusement park rides which accompany most agricultural-regional shows.

At the show grounds, Geelong is fortunate to have a well established antique engine display, featuring many steam powered stationary engines, traction engines, steam trucks, tractors, etc etc., many which live there permanently, such as a ships triple expansion steam engine, and many which are brought in just for the show.

There is also a model engineering display, of dozens of working,  steam powered small engines.  It is always a source of fascination to the many visitors.

A competition is held for recently constructed models, and I was very lucky and thrilled to receive the first prize for the Bolton 12 beam engine.  Second prize was for a rebuilt antique pressure gauge, and third for a Stuart twin cylinder “Victoria” stationary engine.



To see the beam engine working, look at the older posts, at the bottom of this page


The rebuilt antique pressure gauge by Stuart .


Beam Engine Ready for Painting

I uncovered the beam engine last weekend, and thought about painting some of the machined parts. I quite like the look of the machined metal and the rough cast surfaces, but some bits really look as if they should have some colour.

The engine itself is almost fully machined.  Just needs things like gaskets, pump hookups, some bolt lengths trimmed.

The copper exhaust pipe will eventually hook up to a steam condensing unit which is yet to be built.  The condensing unit will be housed underneath.



I am planning to polish the aluminium base to a mirror finish, and paint the dark cast iron surfaces in a dark green gloss paint. Some items I will electroplate with nickel.

I have no 3 phase power in my workshop at present, due to a failed component in the phase-changer, but it has been repaired and will be reinstalled in a day or so. Then back to the machining. The painting can wait.

Burrell Traction Engine

Castings for Burrell steam traction engine.

Castings for Burrell steam traction engine.

IMG_1958 IMG_1959 IMG_1960 IMG_1961 IMG_1962

Beam Engine Column after turning, before plating


I still have not got the hang of this blogging stuff.
I tried to post 3 photos together, but wordpress accepted only the last photo posted.
So here is the first one in the series.
This is the casting of the beam engine column.
As you can see, it is roughly the shape desired. It was quite heavy, and had a very tough external skin which required carbide tooling to break through.


3 photos of the beam engine column
1. The casting, roughly the shape, with a very tough external layer
2 After turning, nicely shaped and shiny, but quickly develops surface rust
3. After nickel plating, not perfect, but not bad for a beginner. The nickel only plated those surfaces which had been machined. A few deep pits on the surface did not accept the nickel plating. I had conflicting advice about the adviseabilty of plating cast iron, but overall, I am quite pleased with end result. I might have overdone the electroplating brightener additive. One colleague called it engine “bling”.



I have been posting these blogs for a few months now, and have had quite a few viewers and views from many countries.

While blogging has been interesting and fun for me, there has been very little feedback or comments.

Feedback is the pay back for the time and expense of the blogger.

So, please leave some comments about the blogs, positive, negative, good, bad, boring, interesting.

Otherwise I will take my bat and ball and go home.



Today I attended this steam rally near Ballarat Victoria Australia.

The weather was cold and wet, and accompanied by my brother Peter and friend Stuart S, we drove the 2 hours from home.

I had only a vague idea about what to expect, but it was so fantastic that I will be definitely going to future events there.

To explain, Lake Goldsmith is farm land, in pretty undulating countryside.  38 acres have been set aside for steam enthusiasts, and dozens of sheds of various sizes have been put up and filled with workshops and machines.  Many of the steam engines were outside, so we were grateful for the shed displays whenever the rain set in.

There were hundreds and hundreds of steam engines, boilers, traction engines, early kerosine farm engines, vintage tractors, model engines.

There was a working timber mill, cutting huge pine slabs, powered by a superb steam engine.  See the videos.

The star of the displays, is a working 90 ton steam shovel


There are 2 “rallies” at Lake Goldsmith each year.
This collection of pics and videos is from some of the 65 sheds containing exhibits.
I thought that I would remember the details but there were so many……
Also, just iPhone pics. Next time I will take my Nikon.


This grand parade deserved more than my iPhone video. The battery failed after only about 1/4 of the parade. It was amazing and inspirational, and uplifting.
Absolutely must see.
Next grand parade in Nov 2014. 1st and 2nd. I WILL BE THERE.

STEAM POWERED SAWMILL, looks bloody dangerous to me!

at Lake Goldsmith Steam rally. 6 May 2014.
This must be the best value for the steam head, mech head, metalworker. male in the world today. I even saw some female types enjoying the show.
More vidoes to follow as my incredibly slow ADSL will upload them.
Next rally Nov 1 and 2 2014


Or something like that…

Last year, when climbing out of the gorge of the Zambesi River, Zimbabwe, I developed an enlarging black spot in my right eye. The black spot progressively enlarged, and I decided that I had contracted one of those African worms which eats its way into the human central nervous system.  So of course I ignored it, and flew home to Oz.

Over the next few days, the black spot became bigger, blocking out about 1/3 of the vision in my right eye.  So I thought, this is not normal, and I consulted an eye doctor.

One hour later I was having an emergency operation for a detached retina.

The eye doctor sucked the fluid out of my eye, filled it with gas, and lasered the retina back to where it should be.  All under local anaesthetic.  A painless but weird experience.  I was totally blind in my right eye for 2 weeks, then miraculously, my sight returned.   Gradually, from the top down, as the eye refilled with fluid.  It was really odd seeing a water level upside down.   Like seeing the sea above the sky.

At least my left eye was OK, but I really got to appreciate the value of binocular vision.  It really sucks when you pour yourself a nice red, only to miss the glass.   And machining is a challenge.

To cut a long story short, my sight was restored thanks to modern science and first world medicine, for which I am profoundly thankful.  Also to Drs Ben Clark,  Patrick Lockie, both expert and dedicated Australian eye doctors.

One year later, I have had another eye operation, this time to replace the right lens, because I had developed a rapidly deteriorating right cataract.  Again under local anaesthetic, again expertly performed, this time by Dr Mark Whiting.   My vision is a bit blurred, and I need new glasses, but must wait 4 weeks.  Meanwhile, I must not work (as a surgeon), and other activities are hit and miss.  Already I am having withdrawal symptoms from my workshop.   Maybe the electroplating would be OK, if I can persuade SWMBO to drive me to my workshop…..

Making a copper boiler

The boiler which powers the Bolton 7 steam engine is 250x100mm. The case is 1.6mm thick and the ends are 3mm thick. It has 7 x 6mm copper stays. The safety valve, pressure gauge, sight glass and valves were bought items. It operates at 60 psi but has been tested to 120 psi. Propane gas fuel.

Bolton 7 Gunmetal castings

Castings used to make the Bolton 7 engine. These are a hard wearing brass alloy called gunmetal. The next post is a picture of the cast iron castings.
Part of the expertise in making these engines is the technical challenge of accurately machining these lumps of metal.

Bolton 7 Iron castings

A lot of people who see my engines do not know what castings are, so here is a photo

Bolton 9 Triple Expansion Steam Engine

My next steam engine project will be to make from iron and gunmetal castings and bar stock, a steam engine which will have similarities to the engines of the Titanic.  It will have 3 cylinders, increasing in size, so that steam passes from the smallest to the intermediate to the biggest, thus being used 3 times before being exhausted.  It will be much more complex than the other engines pictured to date on the blog.  My other engines have taken about a year each to build, so I predict that this one will take a similar time.  We will see.  There will be no rush.  My aim is to enjoy the build and end up with a working engine.  It might even end up in a boat.

I have the plans, and the castings are on order.  The supplier (Kelly Mayberry at E&J Winter, Sydney) had to order new castings, so they are currently being cast and collected.  My next post will be when the castings arrive.  If you are interested, go to the E&J Winter web site and browse the catalogue.  I am not exactly sure about the final cost of the castings but it will be approx $A1500.  Not cheap, but SWMBO says that it keeps me off the streets, and is probably less than belonging to a golf club.

Beam Engine Steam Pipes, variation number 3

The inlet steam pipe was moving a little, being pulled by the governor lever, so I made a new inlet pipe, running it along the base, and silver soldered a bracket to the base to support it. It is more rigid, and I think that it looks better too. The Nitto air line fitting in the foreground, is a custom made fitting, to join the 0.25″ steam pipe to the air compressor line. It was made on the Boxford CNC lathe.

Bolton 7 Boiler changes

The steam exhaust from the Bolton 7 now exhausts into the fire box, and ultimately up the chimney. I am not sure if this will work well. Concerns that the exhausted steam might interfere with the gas flame. Wait and see when I next fire it up! But that will not happen until I make and install a displacement oiler. Another week or two.


In the earlier video showing this engine running with steam, there could be heard a knocking noise. Last weekend I did a tear down to identify and rectify the problem. I found 3 separate issues. First the con rod big end was a bit loose, and required some tightening. Then I found that the threaded join between the piston rod and cross head was a bit sloppy, so that was also tightened, then pinned so it will not move again. (see photo). Finally, and of most concern, the 3 bolts holding the cylinder to the bed were loose, allowing the whole cylinder to move slightly. I think that this movement was what was allowing the piston to hit the cylinder cap in use, causing the knocking. I replaced the BA screws with metric 5 cap screws. Much stronger. Much more permanent. And no more knocking.

Beam engine operating

The Bolton 12 beam engine has now had some “running in” time, and I have made some tuning adjustments to the valve timing.
Is it now running more smoothly on low pressure compressed air. For the video the compressor is turned off, and the engine RPM falls off as the tank pressure goes down.
I do not have a boiler big enough to run this engine on steam, and I am negotiating with a friend to borrow his boiler so I can make a video of the engine running on steam. (Stuart, are you reading this?)


To see the video of the beam engine running, click on the Youtube link on the previous blog entry.

In order to make the video without the compressor noise, I turned off the compressor and ran the beam engine off the tank full of air.  It did not take long to run out of air pressure, as you will see in the video.

Also, engine is still rather tight, but I expect that the motion will become smoother as the engine is “run in”.

The governor is yet to be linked to the throttle valve, so the engine speed varies substantially.

Watch this space for the beam engine to be run on live steam.


Steam Chest Uncovered

I removed the steam chest cover in order to attach the steam supply pipe.
The photo shows the sliding valve (gunmetal) and the valve rod which is moved by the silver coloured rods at the sides.
One of the steam ports is visible underneath the sliding valve.
The photo also shows the 6 steam chest studs which hold the whole thing together.

Steam Cock and valve. Making the handle.



The steam control cock and butterfly valve.

The steam control cock and butterfly valve.

The brass and redgum blank joined with M3 threaded rod

The brass and redgum blank joined with M3 threaded rod

The brass-wood handle after turning

The brass-wood handle after turning

Milling the squared section

Milling the squared section

Drilling the square hole

Drilling the square hole

Filing the square hole corners.  (you didn't really believe that iI would drill a square hole did you?)

Filing the square hole corners. (you didn’t really believe that I would drill a square hole did you?)

Finished handle
Finished handle

Almost Finished Beam Engine

Beam Engine castings

shipment 1 of 3

The castings and plans were supplied by E&J Winter, Sydney, which is now owned and managed by Kelly Mayberry. He has a well established web site with catalogue, prices etc, and he is very interested and helpful with queries during the machining of the castings.
I believe that the castings come from various small foundries around Sydney.
The plans for the 2 engines which I have made so far were drawn up many decades ago, and are rather frustratingly in imperial measurements. So the first task when I receive a new set of plans is to convert all of the measurements into metric units. Then I have the plans laminated, because they get a lot of handling in the dirty greasy conditions of the workshop. Another item on the plans agenda is to make photocopies of the intricate details on the plans, and magnify them x2. I find this is a great help for my rather dodgy eyes.

Beam Engine Governor Gears

The bevel gears on the plans looked rather difficult to make. Finished gears were available from the castings supplier, but on ordering, no, they had not had them in stock for a long time, and even if they were available the cost would be $a254.
So, I tried another option which was successful.
I ordered some angle grinder gears from China, cost $5 per pair, machined new centre holes for brass inserts which fitted the shafts, used Loctite to glue the inserts, and broached the keyways into the brass inserts.

The photo shows the larger gear unmachined at top, and bored ready  for the brass insert at bottom.
The gears were too hard to machine initially, so I put them through a couple of cycles of heat to red hot and slowly cooling, and then my carbide cutters worked…. just. I did not want to risk my expensive broaches however, and that was one reason for the brass inserts. The other reason was to remove some of the angle grinder features from my antique looking model.
The angle grinder bevel gears have curved teeth, which would not have appeared in 1880, but you can’t have everything. It does make them very silent.

Beam Engine Parallel Motion

A close up shot of the parallel motion apparatus which I made for the beam engine. Designed and patented by the famous James Watt in the 18th century. A complex apparatus which is fascinating to watch in action. Its function is to keep the piston rod precisely centrally in line with the cylinder, despite the circular motion of the beam end.