X-Z Carriage Left (Work in Progress)
M8 Threaded Z Axis
8mm Smooth Rods X-Axis, C to C = 68mm
Dual Titan E3D Direct Drive 1.75mm/3mm V6 Hotend Combo X Carriage Prusa i3 Style LM8UU (http://www.thingiverse.com/thing:2004347)
Several design revisions based on first printed part, reduced overall mass and added thru holes for insertion of screws or bolts through the main body into your stepper motor. Enlarged clearance around belt hole as well.