(DIR) Return Create A Forum - Home
       ---------------------------------------------------------
       Office of Steam Forum for Model &amp
       ;amp;amp;amp;amp;amp; Toy Steam Gas &amp
       ;amp;amp;amp;amp;amp;amp; Hot Air Engines
 (HTM) https://officeofsteamforum.createaforum.com
       ---------------------------------------------------------
       *****************************************************
 (DIR) Return to: Restorations
       *****************************************************
       #Post#: 54485--------------------------------------------------
       Refurbishing a model steam engine with a Scotch yoke transmissio
       n.
       By: Tony Bird Date: December 11, 2022, 6:08 am
       ---------------------------------------------------------
       Hi,
       One day a week, most weeks, a friend visits and I give him a
       hand repairing/restoring one of his models.  The latest model
       that we are playing with is a little unusual as it uses Scotch
       yoke transmission for both piston and valve.  Mostly Scotch
       cranks are used on pumps but I do own a model steam engine that
       uses one for the piston the valve gear having conventional slip
       eccentric. Using a Scotch crank gets rid of the connecting rod
       so making the engine/pump more compact.
       The model is scratch built, probably an own design, using
       materials to hand.  It isn’t very well made but who knows what
       machinery was available for its construction.  It was, we think,
       designed as a marine engine being mounted on a mahogany plank
       along with what might have been propeller shaft bearings.
       My friend wants to use as much as possible of the original model
       in the refurbishment of it. A bit extra work but I think most of
       it will be able to be used; famous last words?
       Very little of the model is square so it has been decided to
       reposition the parts of the engine on the original base plate,
       this will probably that some of the holes will have to be
       plugged while others just filled with epoxy.
       The photographs show the model being taken apart, the last two
       being of how far we got in the first session, as yet only new
       holes have been drilled to fit the cylinder columns.
       Take care Tony.
       [attachimg=1]
       [attachimg=2]
       [attachimg=3]
       [attachimg=4]
       [attachimg=5]
       [attachimg=6]
       [attachimg=7][attachimg=8]
       *****************************************************