You will need to print 2 halves and superglue them together.after add some superglue on the 'butt' of the button and push both in the center bearing so both button 'butts' touch in the center of the bearing.

NOTE : This spinner does not use normal skateboard bearing.

The bearing you will need are "624ZZ 4mmx13mmx5mm Radial Ball Bearings"

Ebay link: http://www.ebay.co.uk/itm/10Pcs-624ZZ-4mmx13mmx5mm-624Z-Radial-Ball-Bearings-3D-Printer-Reprap-90014130-S5-/161374736986?hash=item2592af125a:g:mUgAAOSwRLZTz4HH

Prusa I3 steel

Doesn't Matter

Doesn't Matter

0.15mm

100