Thanks, a completely different approach. I will examine that concept tonight. You called it a steam stop valve which might explain how sensitive it was to just the slightest change.
Sincerely Steve Ciambrone Sr. Test Engineer L-3 Ocean Systems Dunno what the hash is Steve but Excelsior is controlled with a single servo for speed AND direction, the original 'throttle being used as just a 'steam stop valve'. It works in the same way as single channel Pearse locos and the reversing piston valve below the smoke box is actually a reverser regulator. You need to remove the reversing gate, fit a servo in the sidetank and make up a linkage using partly the reversing linkage already in place Yours Aye Tag Gorton Longlands & Western Railway Trematon office Cornwall