Stuart Triple new build

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Thanx. Yes, it explains a lot. However, I thimpfks that it would be possible to carve this in CI. I wonder what Stuart would charge for just these two castings. (and how much shipping would be to USA). There is another triple expansion engine I am interested in, I thimpfks with a condenser. As far as I know, there are no castings available for this other one.
I was wondering that too (Why not put all three cylinders into a single casting?).
I guess you could cast a monolithic block if you used piston valves.
I did as suggested by some people and drill all the remaining holes in the cylinder block castings. The drain cock holes and the lagging holes.

20220620_Drilling cylinder block.jpg

and the progress to this point

20220620_Progress update.jpg

20220620_Progress 1.jpg

Have also made the the expansion dies and the valve rod heads visible in the progress photos
And now for a little bling. I decided to make dome nuts for the column/cylinder block connection. Using brass as this was in stock I did a drawing and machined the dome first then holding in a collet chuck drilled and tapped to 4 BA.


20220623_Finished Dome Nuts.jpg

On Block.jpg


Did not get as much done this week as I wanted paying work first to cover hobby costs hopefully more next week.
Hi Everyone
Today I decided to make some gaskets, there are several on the model. I start by drawing the gasket in cad and save as a dxf file then using a laser I purchased recently I cut them all out.
Worked great.


I link to YT showing a short video of my laser inaction

I spend 2,5 year to complete the Stuart triple expansion steam engine with the manual tools and jiggs etc. 😊

Not a new beginner project as this engine is the most complex and dificult to machine, many machinists give up part way through construction so part completed models are often found for sale.
Yes I agree it is a complex and difficult but with a little patience and taking it slow I feel it will be completed. Not certain of the time yet but I will push on and post my progress.
I met a guy at Cabin Fever who built this as his first engine (or so he claims). But he had as a mentor one of the top model builders.
Hi Everyone
I have been on short break. I did get a few parts completed over the last 6 weeks, they include IP tail rod guide and IP Valve inspection plug
Also the slide valves and the valve operating blocks. I have finished the cylinder covers top and bottom and the valve rod glands for all 3 cylinders.
I am working on the connecting rods now will post when finished


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Some progress
I have made the connecting rods using Steamingandy method. It worked out great. I am trying his suggestion regards the oil hole through the centre will see how it goes when running. I did do some minor change to his method see attached YT clip.

I still have to machine the radius where the bearing attaches.


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The Connecting Rod bearings straight forward milling and turning. I machine a locating lip to keep alignment between the halves of the bearing and used Steamandys method to do the radius on the sides.


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Next part is the piston rod easier made by doing it in two pieces so I turned the shaft then the crosshead then a keeper to contain the bush. I have to learn how to take better photos as some of my efforts are not worth publishing will keep trying.


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I looked at where I was up to at this stage and figured I could time the build and test it running on air. I used steamingandy's guide to time the eccentrics and set the slide valve in both forward & reverse and gave it a run on air. I am only doing the High Pressure cylinder today. It worked attached is a link to the YT clip

I am enjoying your build. Thanks for posting the photos.
I hope everything is well oiled when you do your first runs. I even assemble with some Moly Grease I have on machined bearings, bores etc, where I don't want to risk spalling or scuffing. The Molybdenum is excellent at preventing that. A very thin ie of the grease when assembling, then oiling before first run, means no scuffing etc, and the surplus grease is washed out by the oil. The black residual oil looks messy, but is good preparation for a long life.
A lovely model
I have been machining some more parts. I have not explained the slide valve setup the setting of the high and low pressure cylinders slide valves is very straight forward after setting the eccentrics on the crank I used the method described by steamingandy to do that . His picture build has been very helpful, I have seen somewhere else the setting of the intermediate cylinder slide valve and I used that method picture attached

20220924_IP Valve timing.jpg


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