Stuart 5a as a first engine to build !!

Am after some advice please.

I have been going through a lot of old Stuart Turner castings and half built engines that my late father purchased from a school over 30 years ago. As a child I had started to build a 3 1/2 Gauge loco and a Stuart D10. Winding the clock forward I lost my father last year and have been going through these which reignited my enthusiasm to get back into this. I am building a Polly Loco which is machined but wanted to have a go at machining an engine from castings now I have my fathers lathe. AM looking at also getting a Mill.

Amongst the castings, I have put together what seems to be a complete set of castings for a 5a and reversing gear. I'm really keen to have a go at this but wondering if I am biting off more than I can shew with an engine this size or on the flip side of the coin, is a larger engine going to be more forgiving to build ?

I don't know about other folk, but I always find the bigger the better . Or should I say easier and less demanding than small stuff.

One proviso is that your machining kit can cope easily without any dodgy setups to "just cope" with the size.

Andrew.

I will probably get shouted down, but having built several Stuart 10s and an S50, I think they are awful things to inflict on a beginner- he certainly won't be a beginner by the time he finishes! Something a bit larger makes a lot more sense. As you say it is more forgiving and doesn't need such close tolerances. If you have the 5a castings already, and it is what you want to build, just go for it.

You won’t know until you try so give it a go, what have you got to loose.

Thanks everyone, sounds like I was on the right tracks. I did build a D10 as a kit of machined castings years ago, was fun but I can imagine the tolerance on something so small would be less forgiving. Machine wise, I'm looking at several mills, I had thought about the Warco WM18. I'm thinking a lot of work would be easier in a good Mill rather than trying to Mill in the lathe.

One stumbling block, I'd been looking on line about crankshafts as there is no cast shaft. People are talking about machining from sold, is this the way to go or individual parts pressed together ? I haven't got the drawings as yet so am just thinking aloud.

The easiest way to make the crankshaft is from individual parts, brazed or Loctited together, unless you particularly want the challenge of machining it from solid.

The downside of starting on the 5a is that the castings are very expensive. If you mess one up due to inexperience it is quite a blow. I would suggest a few simpler engines from stock material first, such as the Dad's engines which a site search from the site front page not the top of the forum will find.

+1 for fabricated crankshaft ideally loctited together.