This one derived from the original maker, I only made more improvement to this especially the structure. This design would have your m3 bolts flushed in the surface and creates seamless anti backlash/wobble z axis thingamajig The idea here is to accommodate as thin anti wobble/backlash z axis carriage depending on your screw length. Update 5 september 2015 I adjusted the gap between flange nut mount and hole for smooth rod shorter because having them tight fit might make the wobble still there because when there's a backlash, the threaded rod will push itself to the smooth rod and thus the wobble still there (theoretically)There are 2 main parameters; total length - This is the total threaded screw length (head not included) minus - Basically you don't have to adjust this, but this is the thickness of the brass flange nut thread length for screw. Setting this to 0 will have the screw unable to reach the flange The provided stl is for M3 x 6mm bolt the thickness calculated in this script is; total thickness = (total length - minus)+2mm (for housing the bolt's head)