This is my version of a spinner for small hands. It uses one 22mm 608 bearing, and three 1/2" bearing balls.

If printed correctly the balls can rotate freely in the arms, but cannot be removed. See instructions for inserting the balls.

The polygonal edges, and the rotating balls add an additional dimension to the classic spinner.

All that remains is to print the button/axle of your choice. I like this one: http://www.thingiverse.com/thing:2049812 it's what appears in the photos.