Quote Originally Posted by John S View Post
So basically if you only ran 1 and 4 you would have the whole range ?

What about doing just a two speed pulley using a 6 rib Poly vee belt drive and that way you could get the smaller pulley on the intermediate shaft a tad smaller without loosing wrap round as Poly vees' don't suffer from this like V belts and you could probably get to less than 100 rpm.
Yes, that would do it. The front pulley on these machines fits on a large taper so I'd have to make the poly V pulley...

I started thinking seriously about this conversion after I discovered that the original motor step-pulley was the wrong type ('A' section not 'B') I wanted to replace the belts with Fenner's (since they're supposed to be better) and did not want to run them on the wrong pulley. 'B' section step pulley aren't available of the shelf, so I was facing either making one or trying this; I'm glad I chose the later 'cos this works nicely :)