Hi, I've made bearing insulators with various materials, good luck. And as trevinoz writes, it must be shimmed to get the correct end play. If I understand it right, if the armature is too tight you wear out the bearings, too loose you get end play & side movement.
BTW, anybody know if it's possible to fit a steel plate CB assembly (see pic) to a K2F with a brass plate?
Thanks
Erling