Z-Axis microadjustable endstop holder for Prusa Mendel

This is a mechanism I designed for holding for the Z-axis endstop, such that the endstop is mounted to a movable lift that can be tweaked up and down relative to the clamp by fractions of a millimeter with the turn of a screw. Three hex standoffs are attached to the top piece but allowed to travel freely through guide holes in the bottom piece to keep the deck level as you turn the set screw. A spring provides upward tension to keep everything stiff. Relative to the clamp, the endstop is moun