Posted by SillyOldDuffer on 08/12/2019 09:39:55:
I always recommend Stewart Hart's Potty Mill engine : no castings, simple, but challenging enough to make you think!
Stewart is active on the forum and his engine is discussed in a number of threads, for example this one.
Plans available without bother: I used this found on the web without finding any mistakes. As technical drawings go it's rather cramped, and I believe Stewart provides better laid out drawings?
Possible negative for some, it's a metric design.
As a training exercise, I built one in Fusion 360, this image being when I was struggling to learn moving joints!
Dave
Edited By SillyOldDuffer on 08/12/2019 09:44:49
Thanks for your endorsement Dave. If anyone wants a set of drawings just send me a PM with your email address
Stew