Spinner Caps - Expansion Fit

There are pleanty of great spinners on thingiverse; ready to be printed and enjoyed. However, I found myself unhappy with the spinner caps that I printed. I've tried a few different ones and none seemed to work very well. Therefore, I decided to design my own.

These spinner caps are designed to be expansion fit. When both ends are pressed into a standard bearing, the male cap should push the female cap outwards to secure it against the inside wall of the bearing, giving you a much more secure