Originally Posted by
Josh L
Why not try shrink wrap? You can buy the harder clear stuff that would probably keep tolerances close. Alternately delrin step washers would be cool if you could find the right size.
Possible problems I see with shrink wrap are:
1) You don't have a lot of control over the final size. If one layer isn't enough, a second layer may be too big to fit the bearing. You can machine the brass if you go with 2 layers of tube or get shim in increments of 0.001 to get the exact fit if you go with one layer of tube and the shim.
2) Even the hardest heat shrink is still a soft plastic and may flow away from the stress point leaving you with slop in the bearing.
On the other hand, if you happen to find stuff that is exactly the right size, it would probably be easy to replace frequently.
The K&S tubing is about 0.015 wall thickness. You need about 0.0195 wall thickness (assuming the 11MM O.D. is correct). If you have access to a lathe you can get 0.032 wall tubing from McMaster. and turn down the wall to the exact thickness required and do it with one piece with no shim stock.