[bEdhEd]

Whenever we use a drill and sand paper, we have someone hold it on the other side with a bearing. If the shaft is too big, try a bushing or a piece of pvc so you can hold on a little safer.

What seems sketchy to me actually is using linear bearings on an aluminum shaft that has been sanded or turned down. The aluminum may be too soft, and the surface of the sanded metal and possible bending of the shaft could cause binding.

This is not to discourage you, but it's just a precaution from what I speculate could happen. Ideally, linear bearings should ride on hardened steel. If this is what your team needs to get done, it may have to do. Have you lost all possible weight in other parts of the robot?