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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: Bolton 9

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

2 videos of the triple and the vertical boiler and the Southworth boiler feed pump working together for the first time.  Not perfectly yet, but working.

 

First taste of steam for the MODEL TRIPLE EXPANSION ENGINE

I made a video of this first run, but I am experiencing great frustration uploading it, due to our totally pathetic Internet speeds here in Australia.  I will include it later in this post, but the resolution is way down.  I will upload a higher res version next weekend.

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Stuart Tankard’s superb gas fired vertical boiler, was also getting its first run powering a steam engine.

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We did not connect the condenser until later.

OK, so here is the video.  Again, apologies for the low res quality.

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

I was very excited to see my triple running reasonably well on air recently.  But it was tight, and required a decent gutful of air pressure to turn it over.  But it did go!

Then it seized.

The cause was the intermediate cylinder valve rod seizing in its guide.  Probably a bit tight,and not getting any oil.

So I have loosened the gland, installed a displacement oiler, and made and installed a flywheel.  I also finished the pipework around the condenser.

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Displacement oiler top left, brass flywheel, and pipework.  The condenser on a marine engine would have been cooled with seawater, pumped with a separate pump, but I have used the 2 pumps on either side of the Edwards air pump.  In future I might install another pump.  The book “Marine Steam Engines and Turbines” has been been very useful.  

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I just like all of the brass and copper and components in this picture.

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The flywheel is too big for the scale, but my model does not have the weight and momentum of a propeller shaft and propeller, so a sizeable flywheel seemed appropriate.  Later I will add some gear teeth on the flywheel and a cranking handle on a removeable pinion, which some medium size engines had to assist with cranking to a starting position.  

So, tomorrow I will hook my triple up to Stuart Tankard’s vertical boiler, and see what happens.  I am sure that steam leaks will be revealed.  Hopefully there will be a video worth posting!

TRIPLE EXPANSION MODEL ENGINE- FIRST RUN (air)

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.

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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.

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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.

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.

 

2 Triple expansion steam engines.

Triple Expansion Engine Update

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

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

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

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This is the condenser side, and the Edwards pump

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

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And the top, showing some of those 429 fasteners,

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

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

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

Not quite ready to run it yet.

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

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

A Base for the triple, and some oil holes…

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

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

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

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

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

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

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

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

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

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

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

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

 

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.

A Turntable for the Triple Expansion Engine.

I have not weighed the Bolton 9 triple expansion steam engine, but I would guess that it is 20-25lb.  (weighed it.  25.5lb)

Access to the various bolt on bits and pieces has become increasingly difficult and tricky, and involves frequent repositioning of the engine.

I removed the bolt on base and that has improved the situation a bit.

Then I had a brainwave, thought bubble, inspiration  whatever, and I tried a ball bearing turntable….   you know….. one of those Chinese restaurant middle of the table gadjets.

It is incredibly useful!

Here are some pics and a video showing it in place;  just a demo of the engine at its current (unfinished) stage.  I think that the turntable might  become a frequently used tool for heavier models.

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The Bolton 9 on the turntable

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And the latest additional bits…   non return valves on the water pumps.

Assembling the Triple

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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.

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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.

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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.

Triple Expansion Steam Engine -The water pump

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The triple will not be finished by Xmas.  No chance of getting into the workshop while we are looking after 2 grandchildren.  So the new aiming completion date is Jan 6, in time to run the triple on steam at the Geelong truck show.   If I don’t meet that deadline, the next access to steam will be the end of 2017.  I really do not want to wait that long.

So the next component to produce out of a chunk of gunmetal is the water pump.

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There are two cylinders in the water pump.  The gunmetal castings appear to be good quality.

Most of the machining will be done on the mill.  But I need a datum surface, and have decided that the attachment plate is the most appropriate.

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I do not need the small cylindrical protruberance, but that chunk of gunmetal might be handy for something else (eg as a bushing), so I parted it off and saved it.  Lovely parting tool is from Eccentric Engineering.

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Then turned a flat surface.  On the mill I machined it to a rectangle.   Diamond tool is also from Eccentric Engineering.

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The two water pump cylinders are bolted to the air pump.  BA7.  A broken tap is entombed in the air pump forever.

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When I get back into the workshop I will machine the rest of the pump parts.

Drag

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.

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The final 20% takes 80% of the time

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The weighshaft, supported on its brackets.  It will be pinned with taper pins to the shaft.  Also finished the reversing lever and reversing arm.  The reversing arm has gunmetal bushes.  About 2 x 8 hour days in the workshop to make these bits.  Just as well it is a fun hobby.

BACK TO THE TRIPLE

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.

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

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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.

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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.

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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.

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

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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.

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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.

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

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The three pairs of valve eccentrics, and reversing mechanisms.

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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.

Copper and Brass Repair

I accidentally damaged a gunmetal casting (an end plate of the condenser unit) of my triple expansion engine.  I considered soldering a piece of brass or gunmetal and filing it to shape, but decided instead to try one of the 2 part epoxy repair kits.  There are plenty of these with iron/steel coloured material, but for a long time I could not find a copper coloured repair kit.

The damaged, machined casting.

The damaged, machined casting.  I have punched some indentations to increase the adhesion of the filler, then washed it in acetone to remove all traces of grease.

Then I spotted this epoxy repair kit at an Aldi supermarket.  So I decided to give it a try.  Cost $AUD5

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DYNASTEEL, Copper Repair. And this initial blob applied to the defect.

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An hour later, after some paring with a knife and filing.

Next day, after some more sanding.

Next day, after some more sanding.  Appearance not too bad.  More shaping of the casting is intended.  The epoxy repair is meant to tolerate temperatures up to   200 c.    If it proves unsatisfactory I will solder in a patch.

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