It was indeed a rubber mallet that I used as it kept coming loose.How do you know for certain your balls weren't obliterated through overuse at high power? Did you tighten that nut using a hammer?
I have the motor limited to 500 watts which it almost never reaches.
The bearings that went are the ones you see at the bottom of the table. There's one set just behind the main drive cog and another next to the locking ring which we're talking about. That's the one that got crushed on mine. Those ones are I think for side to side play. There are needle bearings for the rotational side of things...all this is theory of course as I'm not an engineer.