STUART MODEL ENGINES

[lancelot]

Hello all,
I am going to build one of the STUART model engines,and as a relative beginner,am asking for any advice and tips as to which one I should start with.
My workshop is fairly well equipped,Myford speed 10.lathe ,vert drill,linisher,buff,reasonable tooling for the lathe,vert/slide,[no milling m/c].
The lathe is METRIC which can be a nuisance at times,as I am one of [the golden oldies]
What are the drawings like,any problems with them,The castings,what are they like for finish and machineability?
Any help would be greatly appreciated,
All the best for now,
John.

[Peter W.]

Hello, and welcome.

I built a 10V about 20 years ago as a raw beginner (now i'm just a beginner and was very pleased with
the result.

I only had an ML7 at the time, and could do ALL the machining on it. If you buy a kit, you also get quite a lot
of bits and pieces, which is handy when you're just starting out. The castings were superb.

Another advantage for the 10V is that there is an instruction book :-
Building a Vertical Steam Engine from Castings
by Andrew Smith.

There are instruction books on other engines in the range of course.

The book and drawings had a mixture of imperial and metric, but perhaps you can get metric drawings nowadays.

All the best,
Peter

[lancelot]

Hello Peter,
I sent away for the catalogue.
From your reply,they seem to be up to the mark.Am I to understand that all of the dimensions are given in [metric and imperial],or some metric and some imperial,definitely not a good idea.
Was there much milling on the model you suggested,and did you do it on the lathe.
All the best for now,
John.

[Peter W.]

The book had both metric and imperial dimensions, and
equivalent sizes for tapping etc.
What i've forgotten is whether Stuart's drawings had both (and I can't lay my hands on them at the moment 8-(

I didn't do any milling. All machining was done with normal lathe tools. If you have a mill, you could probably use it, but it isn't essential.

I have to confess that it took me threes tries to get the
crankshaft right !

Cheers,
Peter

[lancelot]

Hello Peter,
thank you for the information,I will give it a go,and keep in touch.
All the best for now,
John.

[Tel]

I'll agree that the 10V is a good beginning choice. I built one in the early days (around 1979) and it has been a great little engine. Still runs as good as new, even tho' it has done a lot of work in the intervening years - including several 8 & 9 hour non-stop runs.

[lancelot]

Hello folks,
just finished the Justins hot air engine,she tried her best to run,but needs a few mods and tweaks.
The 10v is at the last lap stage,valve gear assembly and paint job.Cutting the bearing seatings ,using a 7/16 ballnose cutter with a vertical slide [no mill as yet]was NUT jarring to say the least.The Stuart castings are excellent ,but leave very little room for error.Looking at the one named The'' Score'',anyone got any comments r/e build e/t/c.
All the best for now,and have fun,
John.

[Tel]

You won't have any problems with the 'Score' John, it's just a 10V doubled up & laid on it's side

[the_viffer]

10H (and Score) crosshead guides are a bit fiddly: rather tricky to hold them well in my experience. I rate the 10H as a harder job than the 10V but of course you'll have learnt a few tricks while making the first engine.


Never did manage to machine the crankshaft casting. First one I did I silver soldered out of gauge plate and silver steel. Begineer's luck or what but it came out well

My youth was more misspent than yours Terry. I made my first ST in '75 (I'm only 14 now) and they don't list me as a "mature" member. ... since I'm immature I suppose.

Shame I'm not as good an ME as you tho'.

[lancelot]

Hello folks,
I hope all are keeping well.
I have completed the 10v,the Justins is on the ''long finger ''presently,and I am now working on building the Score.
The box bed is completed,the Soleplate is finished ,except for stud holes,I did the bearing seatings on my new milling machine,conquest ,from chester,using the ER25 collets from my lathe tooling,+stepped down drawbar m/t 3---m/t2which I made from an old Rawl bolt.The mill handled the job very well.boring the two Cross head cylinders was fun,set up was -----angle plate to 6'' faceplate, balance weights,and all well secured,lathe danced a weeeeee! bit,but job well done.
Two cylinder bodies finished,and thats it so far.
Quality of castings found to be very good,although some were a bit rusty,possibly storage conditions?
Tolerances still very tight,no room for error.
Will keep in touch,
All the best for now,
John.

[Tel]

Congrats John, sounds like you are forging ahead. Doing better than me anyway - barely seen the inside of my workshop for several weeks now.

Pics in due course?

[lancelot]

''Trouble in't Mill''...Oo doggie doodaaas!!I have just knackered the valve chest.0n last lap of machining ,the fine adjustment on the mill,decided to act up and took a wkacking great lump out of the side of the chest.
Having sussed out the problem with the Mill,I am now left with the decision as to whether to repair the valve chest or scrap it and start anew.I could plane down the side and rebuild to size with gun metal strip,and silver solder on,''how well does gun metal or brass take silver soldering to cast iron''.also at £5.50 for a new chest,would it be worth al that trouble?
Regarding the mill,Chester's Conquest,...I am possibly going to have to completely strip down the fine adjustment mechanism,and re build,it is really not a very well engineered part of the mill,and will need a bit of fine adjustment to make it behave.
On a slightly different tack,has anyone ever built a Boiler,capable of steaming the 10v or Score,Is it really worth the trouble,re/cost ,time e.t.c over obtaining a second hand boiler,and taking your chances.
All the best for now,
John.

[Tel]

I've built a few boilers for that application. Probably the best for your application would be the 'Monarch Steam Plant' freatured in EIM quite a few years back. I've put up two of these (gave the first one away to an up and coming model engineer - then decided I really did need one after all) and they will run three or four engines at a time if you manage 'em properly.

[lancelot]

Hello all,
seem to have sorted the problem with mill, I made a new valve chest no problems, so chests and cylinder and piston assemblys completed and fitted to sole plate. May be trying to teach my grand mother to suck eggs here,but I think it would be a good idea if the P.C.D. for fitting the cylinder bodies to the sole plate was increased a nhimmel [bit],reason being, the studs are a little to close to the sole plate casting to enable the nuts to go on in some cases.
Crankshaft manufacture was entertaining to say the least, judging by the amount of material supplied and the drawing dimensions I had been short changed somewhere,so bearings and shaft and web assemblies were made and set up in the sole plate assy/ so that all was in line,and left enough room for essentric sheaves and flywheel,just***,I then loctited mildly and drilled and pinned shaft and webs, I was then able to silver solder the webs and shaft to completion.
All the best for now,
John.

[lancelot]

Hello all,
An update on the SCORE progress.The crankshaft is causing problems ,due to warping,I think this is due to over heating during the brazing process.I will have to find some way of safely fitting in a brazing hearth in the workshop. Most of the other bits are ready for assembly.
Sent for the ''Tich'' loco drawings and enough of the materials to get the frame assy/ together,so I will most likely be asking lots of questions off the group in the near future.
All the best for now,
John.

[Tel]

John, by a great stroke of good luck they still make hammers - use one to bash it straight again.

You didn't specify, but the way I do most crankshafts is to use a piece the full length of the shaft, assemble your webs & crankpins onto this & fasten by your chosen method (silver solder, pins, whatever), THEN (and only then) cut out the bits of the main shaft that fall between the webs.

[lancelot]

Hello Tel,
I have a very large and ugly 7 seven pound hammer,with which I was going to make some minor adjustments to it, but on having second thoughts I decided that I would make another one at a later date,
No, I made it exactly the way that you described, the final cut after silver soldering and cooling.Two thoughts on reason for warping, cooled it too quickly or one or both web holes out of alignment. The next one is going to be perfect !!!. What I do need urgently, is a brazing hearth made and fitted in some where safe. I was I now realise, working with the workshop door wide open, therefore losing a lot of heat control which may have been another cause.....So it is going on the back burner for a little while, the Missus is going to hide the hammer while I have a think about it.
All the best for now,
John.

[Tel]

Fairy nuff mate, scaling them Tich drawings up to 5"g will give you plenty to do for a while any'ow.

;D

[ron]

If it's of interest to anyone, the latest Stuart instructions for the 10V give a choice of silver soldering or loctiting a built up crank, they don't supply the old type forging anymore, I made both out of curiosity, I was a bit doubtful of the loctiting method, but it's very easy and the crank was OK after a half hour run flat out on steam.
Ron

[lancelot]

Hello all,
''SCORE'' build on hold until the warmer weather as I am building the brazing and welding hearth in the ''GREENHOUSE'' of all places, no safe room anywhere else.
I am now starting to build the large boiler ''TICH'' . will post my efforts elsewhere.
I wish all a happy holiday and a good future,
All the best for now,
John.