Thanks to all for the responses. My issue with slowing was solved by a couple of drops of super glue on the spindle which bound the pulley securely--that was where the slipping was occurring. If that didn't work, I would have had my machinist drill and tap for a set screw. Two more issues to address (and I'm listing these for the person two years from now who tries the same upgrade!): 1) I had installed the VPI sorbothane feet to replace the springs but they raised the chassis (and platter) about a 1/4 inch too high for the belt to position correctly. I replaced the old springs and the height is correct. I have ordered some Herbie's Tall Tenderfeet which should be the correct height (and should solve the potential issue of the springs being overly compressed). I could have attempted to modify the VPI feet, but really didn't want to start cutting. 2) I have raised the armboard height by using cork discs as spacers between the acrylic armboard and steel chassis and I have been advised a solid machined metal washer or spacer would be better since the cork will eventually compress and potentially affect the azimuth. So that's left to do. It's been a interesting project!
