Z Axis rod/screw support

Summary Lightly modified version to avoid the outer face over hanging the edge of the frame linked here - http://www.thingiverse.com/thing:1800202 Simple top support for the Z axis on the Max Micron 20/20 aluminum frame printer to replace stock as the acrylic seems to easy to crack. •added return down back side for squaring easier, and a hole for a 3rd bolt if you want (thought not really needed) •Added nut holders on the underside of the rod stop so no wrench needed in that tight spot. (note, you don't need to crank those tight, just lightly snug to the rod so it can't pop up too tight will actually push too hard down on the rod and twist the motor mount out of alignment) Also will be adding higher standing ones soon after i design new Z motor mounts As we can easily get 10mm more height with a few minor mods.