My hobby for many years has been building & running miniature coal fired steam locomotives in 7 1/4 inch gauge.
Although never trained as a metal worker, I just picked it up by reducing loads of metal to scrap. My first model engineering project was a "Victoria" horizontal mill engine which runs very well. A succession of model steam locomotive re-builds followed in 5 inch gauge, but working on other people's failed projects ie: part finished models, is more difficult sometimes than building from scratch! ... Although a Stanier "Black Five" in 7 1/4 gauge, which I bought part-finished, built into a fine locomotive. unfortunately I sold it to part finance the purchase of a house.
Currently my workshop is quite well equipped, with a brilliant old "Smart & Brown" British lathe from the early 60's. This was bought from a local tool dealer quite cheaply .... a bargain .... It was in a bit of a state, having come out of a school for kids with learning difficulties, someone had thrown away all the gearbox change wheels to disable the automatic feeds.... because of this, the gears were in first class condition, although a bit rusty in places which was easily rectified. A couple of months were spent rebuilding this lathe & the only new parts used apart from the paint were 2 leadscrew bearings & a 2:1 ratio toothed belt and pulleys for the gearbox drive, to replace the lost changewheels. It's quite large, having the most substantial bed for a 6 inch centre lathe I've ever seen! I bought a new 3 jaw chuck & a 4 jaw self centring chuck for it, as well as a high quality multi-size collet chuck. Completing the renovation, I removed the old 2HP 3 phase motor, & fitted a single phase 1 HP motor to it. It runs really quietly & removes metal at an alarming rate!!!!
I also have an old Taiwanese milling machine which is a bit naff, but mills perfectly, in fact I break less milling cutters on this than on a larger Senior M1 milling machine that I used to have.
A grinder/polisher, 4inch belt sander, large vice & hand tools complete the set-up. With this workshop I also used to manufacture new parts when needed for the two 24 track" Soundcraft 760 Series" Multi Track recorders at the studio. This was the original plan!
I recently bought a Boxford AUD lathe with collett chuck....this will be useful for small part manufacture while the big machine does long, heavy slow cuts.....two lathes at once....!!
Around my home runs 400 feet of 7 1/4 inch gauge railway track completed in 1995 by myself & friends... on this I run an 0-4-0 tank engine with tender...............A long flat passenger truck allows mobile sunbathing in summer.....another one is under currently under construction.
I built the engine & tender in about six months (not the best engineer, but one of the fastest!).
The drawings were L.B.S.C. 7 1/4 "Tich" drawings (Kennion Bros.)....
It is however much modified, having ball races everywhere except the big-ends & con-rods (which are bushed with oilite)...I found some 1/4/inch O/D ball races which allow use in all places where there are pins & bushes normally. This engine has done a lot of running around my garden often at high speed too! Apart from the big ends & connecting rods, wear isn't evident anywhere else.
Notes regarding my “Tich" locomotive.
I built my Tich (obsessively) in about 6 or 7 Months of spare time not including the boiler which was silver soldered together by a friend of mine, Mr. Randy Blackburn (who is good at Copper Smithing & just about every aspect of model engineering). the locomotive has ball races on all the rods except the coupling rods & big ends.
If you are building one, I recommend that you bore the cylinders out, to 1.5 inches, the power output is much better.
I used “Sweetpea" cast iron cylinders & valve chests, with Simplex slide valve castings, all from “Blackgates Engineering".
Also I used 1/4 inch stainless steel for the valve rods & 5/16 inch for the piston rods.
The 3/16 inch diameter rods, as per plan, bent in no time. On the Kennion Brothers drawing the reversing lever is shown fitted the wrong way round. I altered this so now when I push the reversing lever forward the engine also goe in a forward direction
The ball races that I used for the rods, are 1/4 inch o/d & 1/8 inch internal. They are fine & show no sign of wear yet. on the axle boxes. I used 2 ball races (not self-aligning type) in each box, this was a bit over the top, but again no wear is evident yet. the only wear is on the crosshead shims + coupling rods & big ends, which are “Oilite” bushed, using commercial “Oilite" bushes which are easily replaced.
The sum total of all the above modifications is a small & powerful engine which shows no sign of wear in the valve gear, even after a few years running. A few tears prior to building this engine I bought a part finished 7 1/4 gauge Tich & finished it, but as it was built quite badly, it was very poor runner.
My project in the late 1990s was a 7 1/4 inch gauge "Sweet William" 0-4-0 which also had the same treatment as described above.
I never competed this though, as pressure of work made it impossible to finish it so it was sold as an almost complete rolling chassis with a professionally built copper boiler.
"Sweet William" and "Sweet Pea" miniature Locomotive Plans & all castings are available from Blackgates Engineering,
I must thank them for all their help, advice & cutting of odd sizes of metal for me over the years. Their castings are always of very high quality, no problems have been encountered at all. Their service is highly recommended.
The "Sweet William" Steam Locomotive that I part built is narrow gauge, so it's big (Built like a tank) in 7 1/4 gauge...but very easy to build ....nearly ready to run on air after an incredibly short time. ...everything is big so you can machine more heavily without breaking anything (Sometimes!!?!!) This Loco also uses ball races where possible, the split bush con-rods & big-ends are used to clamp onto oilite bushes, which are quickly replaceable, & run on case hardened crankpins. These are a bit fiddly to make & set up, but the ease of maintenance later is worth it.
Part of me still wants to be an engine driver, so who knows...one day I might set up a commercial light railway...?
At this moment though, it's not far off running on compressed air! no boiler as yet. Boilers are the single most expensive bit....the copper alone costs a fortune, the firebox outer wrapper is 1/4 of an inch thick!
By the time the boiler is made, the engine will be well run-in on air. I have an old dental compressor, which runs very quietly, as it's fully enclosed, so I can listen to the engine's mechanicical noise, this is useful for fine adjustment of the motion. Usually when first running on air, the pressure needed to start is 30 - 40 psi.... but after a short while, the engine should tick over on 8 - 10 psi ....Normally I blank off one side of the steam (or air) inlet,feeding air to one side only, to get the valve settings spot-on one side at a time. When both sides work together, an efficient ....or reasonably efficient machine results. Steam locomotives, even miniature ones are not efficient machines at all....most of the energy goes up the chimney as exhaust heat. Most miniature steam locomotives are built & run almost in the same way as full size & so they wear out to scale .....fast!..... even the amount of ash in the smokebox after a long run is to scale!