I know a lot of models, notably the Ruby, and the Accu C-21 use a modified Stephenson valve gear… can someone explain the difference between the model version and the prototype version?
Furthermore …
With the “Ruby” the cutoff is not supposed to be variable, but I know with mine if you “choked up” on the J-bar a bit, it tended to run better (and longer!), and the stack sounded crisper when running. Not sure why.
The only locomotive (1:1) I’ve actually run with Stephenson gear only had two notches forward, and two reverse on the transit for the J-Bar … one all the way in the corner, and one just slightly up from that… does the prototype Stephenson have no variable cutoff as well?
An explanation of the difference would be great.
Matthew (OV)