Grinding Victrola motor parts for smooth operation

[startgroove]

It is likely the ball bearing was used as a low friction method of supporting the downward load of the shaft, turntable and record. In addition, the hard steel shaft running on a hard steel ball would be much more wear resistant than running the turntable shaft directly in the cast iron bearing support.

[JerryVan]

I'm with Jon, the cup would not have been there originally. A ball bearing against a hard, flat surface would create the least friction in a thrust bearing. Why would Victor want any less than that?