On Friday, August 16, 2019 at 1:54:36 AM UTC-4, Andy wrote:
I have a bench grinder that i bought in 1986. The label says "all ball bearing motor." Is that motor different than other motors?

Generally there are two types of bearings, ball or sleeve and ball ones cost more and are better for many applications, including that they can be replaced in many cases if they wear out. On the other hand it a sleeve bearing lasts the life of an infrequently used, not so expensive thing, it can be well suited to the application.