Vertical Adjustable Opto Z Endstop Holder (Q89944)

I found it difficult to adjust my z-axis endstop precisely (fractions of a mm) once it was close. I could only find one other adjustable endstop for opto switches, however it mounted the switch horizontally, which wouldn't work with my printer, so I've modified it to mount vertically instead. I've also made it a bit more stable than the original design and it's very parametric. This is a derivative of: http://www.thingiverse.com/thing:15448 It also uses the awesome knurled surface library: http://www.thingiverse.com/thing:9095 The library is embedded into the .scad file so you won't need to download it separately.