Updated Z-Axis Rod Holders for F624ZZ bearing for Smartrapcore ALU

I had some trouble keeping the belts on the bearings so I finally got around to rebuilding these mounts.

These parts are intended to work with DjDemons z-axis remix:
http://www.thingiverse.com/thing:1417053


Onshape design is public here:
https://cad.onshape.com/documents/e290625bf29788e6760d2ac9/w/dcf071c9164a560f53e72f3b/e/f71ad74bdd45e6d3cd55ef21