PM research #3a steam engine

Hi, I`m thinking of building a PM research #3 steam engine. This will be my "first blood" into machining. I have a lathe and mill. Would anyone recommend this as a first engine? Peter

It's the American equivalent to the Stuart S50 and reasonably popular over there as a first casting kit engine. You are likely to get more help on this forum with an S50 as people are more familiar with them or have actually built one, different on one of the more US based forums.

I don't know what your preferred system is but the PMR engines are in imperial and will use UNC fasteners so taps and dies required for that which may nor get used much unless you stick with US designs in the future.

In many cases you can probably use a close metric thread to replace the specified UN thread. The difficulty might be some rods which are 1/8' dia and are end-threaded 5-40 UNC to suit.

Jason's suggestion of a Stuart Models S50 is a good one. Also a very popular engine with folk starting on the steam engine route has been a Stuart 10V. (I made mine about 10 years ago.) Tee Publishing produce a book titled "Building a Vertical Steam Engine" by Andrew Smith to give some guidance.

What you get in the kit:

How mine turned out:

For some reason it looks a lot brassier in the picture than it is in reality; the flywheel, cylinder and steam chest are polished cast iron. The air connections and pipery are not included in the kit.

Jim

That's fair comment. I built PM's No.7 horizontal twin a while back, and substituted comparably-sized BA hex fasteners for the slotted screws provided with the kit.

Edited By Mick B1 on 31/03/2021 12:05:59

I think I will go down the route of the Stuart Models S50. Many thanks, Peter

In that case, Peter, please ignore my PM.