Summary

I created a quick-to-print magnetic spinner.
BOM:

• rotor x 2
• side A
• Side B
• 3 screws with cylinder head: 2.5mm X 5mm (4 - 7mm would be just as fine)
• 3 inserts (insert nuts) 2.5mm
• 7-9 5mm cube magnets
• 608 ball bearing (22x8x7)

no supports needed
I strictly recommend a 0.4mm or 0.6mm nozzle with layer height of 0.25 and layer width of 0.6mm. Two perimeters and four bottom layers would add enough rigidity. Infill can be set to anything between 15 and 100%.

You can try different configurations of the magnets - e.g. attractic polarity in the two outer slots or one in the middle. You can also try repelling positions.