Here is a screenshot of the bearing holder - designed it in SolidWorks. I'd make it out of 6061 Aluminum. It needs to be dead-nuts correct in the inner bore - so the bearings sort of 'press in' by hand. The depth of the pocket leaves about .005 of the bearing sticking out - so the top plate can be used to hold them down and in position.
I made four 'relief' holes (1/2") that go all the way through the main part - so that one can use a wooden dowel rod or something soft in case they need to "tap" the bearings back out after the machine operations (from behind). I usually forget crap like this - than wish that I didn't!
Can't say that I've ever attempted to 'bore bearings' on a lathe, but there is no reason it can't work if the machine is good and the operator knows how to do precision work.
If anybody wants a copy of the CAD model, just ping me . . . not a big deal by any means.
B&S
2-14-2016 1-26-16 PM.jpg