A glue on mod to move the z-axis homing adjustment to the front right of the printer. Note that there was talk of reserving this area for a spool holder. The switch is mounted on the regular ZEST part. Version two uses splines to lock the screw so it can't rattle out of position.3d printed and tested but slic3r (at 0.2mm) does strange things. There are no errors reported by slic3r or netfabb but in my case it added a single fill layer to the hole and printed the back and side walls hollow. The hole is small and intended to be tapped to M3. There is enough material to allow larger threads to be used. I printed in PLA and superglued it to the existing ABS part.Version-2 is a bit more challenging. The pieces fitted together with minor filing and clean up but I don't know how well this will work when printed on another printer.When completed the large knob with internal spline locks the two 10 tooth splines together. To adjust you lift the knob off the lower spline and rotate. When in position lower the knob to lock again.