Fidget Spinner：笼形螺母和轴承

Pause at layer height 8mm to iert nuts (5/16"-18) and ball bearings (608ZZ 8.22.7)
This fidget spinner has caged parts (meaning, the nuts and ball bearings can't fall out). Of coue the bearing caps could potentially come apart, so I still wouldn't recommend them for young children. (Unless you leave off the bearing caps, then they should be okay with supervision.)