I intended to make a super compact 6 sided spinner that uses (6) R188 (1/2"x1/4"x1/8") bearings. The bearings don't quite seat parallel to each other so the cube has more of a wobble behavior than a spin.  Actually makes you fiddle with it more than spinner.

I printed with PLA and needed to scale the cube to about 103% in order to leave tolerances for the bearings.  I also has to do some sanding on the plugs.

This object was made in Tinkercad. https://www.tinkercad.com/things/gZooIMiGs4E