FYI: VPI HW-19 motors

Well, I made the upgrade--had the acrylic/steel chassis drilled out to accept the new bearing.

Everything seems to work fine (better) except after playing one side, the platter slows and pitch changes. Any theories as to what's happening? Is the belt stretching out? Is the motor being overwhelmed? Platter is level (bought a run out gauge to help level it)and the bearing was lubricated with Mobil One and spins freely without the belt.

Suggestions?

Mr A- It's possible that your belt is slipping slightly, heating up from the friction(at the pulley), and expanding. If you allow the table to rest(turned off) between sides: do you still have the same issue?

Bob...it could be that the pulley is slipping a little bit
on the motor shaft.

Some of the pulleys had a tiny set screw and some were just
press fitted on. If it has the screw, tighten it. If it
doesn't, push down on the pulley with a little force to
reseat it on the motor shaft.

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!