I made this bearing to test my 3d design skills for my high school's DaVinci class. Not perfect as I was just getting into designing my own pieces to print.

I figured I'd like to have it out there if anyone else wants to play around with it.

I printed it both on a Geetech A20M (School's printer), and an ender 3 (Personal printer). No rafts or supports are needed. I think I used 20% infill, but the last time I printed it was a while ago.

The middle cylinder isn't needed and can be thrown out (pretty early in my design knowledge so I didn't quite know how to move planes), it was to base where the middle of the balls were.

Creality

Ender 3

No

No

20

It might be a little tight at first and maybe connected at some points, so just twist it around a bunch and try to get everything free. It should wear down and spin easier as you keep messing with it.