Horace, Just for the hell of it, I am making a new bearing motor out of automotive bearings, the old conical roller type used in the front wheels of rear-wheel-drive cars. It's almost done, but I unfortunately ran out of 5/16" nuts tonight, so cannot continue until tomorrow evening.
Two bearings, National SA-12, used in the outer front wheel bearings for Mercedes-Benz E320 were given a smaller inner diameter to fit a 5/8" shaft by pounding steel sleeves into them. U bolts support the bearing races. Very similar to the BB motor I already have, and what you're running on your end. Only the bearing type is different. I'll try and complete it tomorrow night, as it is a simple project, and see what happens. --Kyle