OK,
here's the same basic idea with the CB facing the "right" way. I didn't touch this up in PSP though, it's just a direct Excel screenshot (OK, I was lazy). This one is nicer in that there is not thickness problem, and you can use regular 5X8mm bearings. Securing the motor shaft might be a little hard to go to though - maybe a small hole in the CB to allow an Allen wrench to get in there?