50mm gear/spool solution for filiament winder.

I like where ianjohnson is going with his winder project but it is built around using his spool design and I have tons of the 50mm hub spools laying around. (The same type that MBI sells) So I made a solution to print everything needed. You just need 3 608 bearings and some threaded rod and nuts. The gear is compatible with ianjohnson winder. The gear has a bearing on both ends and the cap has a bearing. The knob which is http://www.thingiverse.com/thing:3723 has been shorten so the nut sticks