Per a request, here's a Musical Notes fidget spinner. This spinner uses (3) 5/16" nuts and one 608 skateboard bearing. The overall diameter of this spinner is 3-1/2".
Printer Brand:
PowerSpec
Printer:
PowerSpec 3D Pro
Rafts:
No
Supports:
Doesn't Matter
Resolution:
0.2mm
Infill:
50%
Notes:
If your printer can bridge over the holes for the nuts, you won't need supports.