A bearing based fidget I designed for an nephew that likes to spin things as a stim behavior. Regular bearing balls wheren't sticking to the bed, so I attached cylinders to the bearing balls to keep them ontrack. The cylinders will slip horizontally, but they will still spin.After printing, you may have to break the cylinders free. However, it shouldn't take more than simple nudge to break each one free. Once free, they should spin easily.