About this 3D model

These x-ends don't hold x-rods, they hold a single 20x20 extrusion. This particular version uses lm8uus and a 2 hole delrin nut for the lead screw. both ends have an integrated bolt holder meant to interface with a z-endstop held in the lower part from http://www.thingiverse.com/thing:28425 By the way these are intended for 605zz idler bearings, you'll have to enlarge the hole either before or after printing if you intend to use 608zzs. If you need a bushing version look here http://www.thingiverse.com/thing:34487