Posted by Tom Ramsey on June 02, 2009 at 09:30:16:
In Reply to: Gear setup posted by Sean on June 01, 2009 at 13:21:15:
I havn't seen one in 20 years but as I recall the PG is part of the index forula. It allows you to expand the ratios to cut small or large numbers of teeth. I think it was a fixed center distance allowing 1/2, 1/3 etc.