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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.

Tag: model steam engine

Trevithick Dredger Engine Progress

First day of summer in southern Australia today.  And it was very warm and windy.  Keeping my eyes open for snakes, but none seen.

I was pondering how to attach the crankwebs to the flywheel.  I had decided that I would not silver solder them together, because the heat would likely distort the thin flywheel.  And pressing them was not feasible because I had machined them to a sliding fit.  Whatever method was used, I wanted it to be reversible i.e. future disassembly possible.  So, in the end, I used small brass screws which will not be visible when the engine is painted.

 

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countersunk brass screws holding the assembly together.

 

I made 2 more U shaped bearing retainers to fit on the ends of the connecting rods (same as shown in last post).

Then made 2 shafts which will be attached to the cross head bar, to join to the con rods.  These are made from silver steel.

 

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The concave end had a radius of 10mm.  Fortunately, I had a 20mm end mill which worked well to produce the curve.  A bit of finishing required for these parts.  I will probably run them for a while in my gemstone tumbler to knock off the sharp edges and polish them.

 

 

 

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They will be pinned in place at the ends of the cross head bar.

 

Trevithick Dredger Engine Guide Bars and Crosshead

 

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As you can see from the photo, I have made the vertical guides, the curved top bar and the crosshead.

 

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The curved bar was bent in the motorised ring roller which I made years ago.  Bending 3.2mm steel was easy.  I have bent steel bar up to 10mm thick in this machine.

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Parts of the guide bar.  2mm thick.  I confess that these were CNC’d.

 

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A few more parts required for the crosshead, but a test fit was quite good.  It is just pushed together at this stage.

 

 

 

 

 

Trevithick Dredger Engine….progress

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Finishing bits on the engine assembly.  The stuffing box, the gland, and a threaded plug in the throttle cylinder.  Throttle valve, stem direction valve,  piston and piston rod next.

Running in the Triple Expansion Engine

The Bolton 9 engine is assembled, almost completely.  The valves are approximately correctly timed.  I can turn it over by hand, just.  There are a few tight spots.

So today I mounted the entire engine in a lathe, oiled all bearings and slides, and tentatively ran it for a few minutes.   The lathe was set at 60rpm, in back gear.

All seemed OK, so I ran it for about 30 minutes.   Then increased the rpm to 90 for another 30 minutes.  After that the tight spots still exist, but much less pronounced.

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I kept a check on bearing temperatures with a laser thermometer, and none were running more than a degree or two different from any others.

The test did show that a low pressure cylinder drag link is touching the condenser, and will need some relief.  Also the high pressure cylinder eccentrics need to be repositioned a little on the crankshaft.  But nothing major.  And it was very nice to see everything moving in quite an impressive manner.

I will upload a video when the upload speeds are reasonable.

 

Horizontal Mill Engine (HME)

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

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

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

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

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

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

But it goes!!   Yay!!

 

Koffiekop Modification

I have been considering this modification for some time, and today I located the aluminium heat sink-radiator material which I needed, and which I knew was somewhere in my stuff.

The Koffiekop Sirling engine requires differential temperatures between the top and bottom plates.  I wondered if installing some heat shedding plates on the top plate might increase the running time on a cup of coffee.

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The heat sink material is glued to the top plate with a heat transmitting electronic silicone glue.

Afterwards I ran a test with a cup of hot water.

The engine ran for 26 minutes!  That is an improvement of about 25% on the best previous runs.  Success!

The Horizontal Mill Engine (HME) is assembled and ready for the D valve to be timed.  This is how it looks.  I wont get to it for a couple of weeks now.

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I did squirt some compressed air into the valve chest, but minimal movement.  Not surprising, considering the position of the eccentric was just a guess.  When I get it going there will be a video.  That crankshaft pin is temporary.  It is a 3mm cap screw going through a 4mm cap screw.  go figure.

 

If at first you don’t succeed…

Try again.

The small reversing handle lock on the horizontal mill engine took 4 attempts.

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Most of the components are made.  That is my blood staining the plans.  

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The lock is made of brass.  About 32mm long, then bent into shape.

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From the left.. 1. broke when turning the thread.  2, cracked during bending, not enough heat.   3. Too much heat melted the surface.  4. Success.

And on the same subject, the cylinder head and guide went well until I neglected to remove it while finishing the guide block.

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I might have mentioned this one previously.  It still rankles.

Another Diversion from The Triple

My model engineering club (GSMEE) has an annual competition build.  This year it is a small horizontal reversing steam engine.

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So I have taken another break from the triple to build the HME.  I have redrawn the plans to make my model 40% bigger, and also to accept metric fasteners.

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The HME blanks for the base, the cylinder block, the flywheel pillar and the flywheel.  The only stainless steel I had in my junkbox, er storage facility, had a  big hole in the middle, so I filled that with brass.

All was going well, and I spent almost a day making the piston head guide. Then finished off by making the guide rod and block.   I decided to take another thou off the guide block, and set the lathe going.

And heard an ominous bang.

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I had forgotten to remove the piston head guide from the from the piston before I restarted the lathe.  Destruction.  The lump at the bottom is another piece of brass, ready to be turned into another head guide.  I had run out of suitably sized brass, so I silver soldered a length of rod to some square section.  A day later and the new piston head guide is now made.  

At least I know from this (and other crashes), that the second part is always made much faster than the first.

And on a different subject, I recently bought on Fleabay a self centering 4 jaw chuck.

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It does not replace the independent jaw 4 jaw chuck for accurate work, but will be useful for turning small square stock.  Also, I plan to make a backing plate for it to fit into the tailstock, so it will hold taps.

Triple Expansion Steam Engine Pipework.

I am close to disassembling the Bolton 9, before gradually reassembling it in preparation for running it on air then steam.  Most of the components have now been made.  Most recently I completed the pipework associated with the Edwards air pump and the twin water pumps.

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This is the combined air and water pumps, and new pipework.  Most joins are silver soldered, but a couple are Loctited.  Loctite should be adequate.  These components will not get super hot.

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This valve is one of the few components on this engine which I have not personally made.  This one came from the effects of the late Harry Close, who was a valued member of our Model Engineering Club.

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The pipework adds to the overall interest , yes?  It will look good when polished.

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And the “tails” for the valve rods, which are attached to their respective steam chests.  The BA7 bolts are a bit oversized for the job.  The intermediate cylinder tail screws into place.  I am not sure why it is different from the other two.

So now I am making a list of tasks which need to be completed when the engine is taken apart, hopefully for the last time before it is run.  The list is not complete, and so far it runs to 3 pages.  Mostly like fixing parts which interfere with each other, and freeing up tight bearings.

I will take some pics of the components.

Edwards Pump for the Triple Expansion Steam Engine

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

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

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

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

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

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

 

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

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

 

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

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The pump unit viewed from the side.

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

JOINING DARK PLACES

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.

TRIPLE CYLINDER HEAD CAPS

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The head caps sitting in position.

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

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

 

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

GSMEE EXHIBITION 2

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.

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Vacuum engine made by Peter Bodman.

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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”.

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

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

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Hull with the superstructure removed

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

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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.

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

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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

 

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Close up of the marine engine by Walter

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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.

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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.

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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.

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

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

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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.

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.

TRIPLE EXPANSION MARINE STEAM ENGINE 3

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.

TRIPLE EXPANSION MARINE ENGINE 2

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.

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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.

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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.

NEXT LAKE GOLDSMITH STEAM RALLY Nov 1-2

The next Lake Goldsmith Steam Rally is on November 1-2, near Ballarat, Victoria, Australia.  Google it for information and directions.

As well as the usual cornucopia of all styles and sizes of steam and other antique engines, including the massive 90 ton working steam shovel, and the working steam sawmill (see older posts on this site for videos), the rally is making a feature of CATERPILLAR machines.

I will be there.  Along with many many other machine addicts.

CASTINGS ARRIVE AT LAST!!

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

ROYAL GEELONG SHOW

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.

 

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

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The rebuilt antique pressure gauge by Stuart .

 

Burrell Traction Engine

Castings for Burrell steam traction engine.

Castings for Burrell steam traction engine.

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