Update: Mount revisited, improved for more tightened fit.
Attachment for X cariage of Prusa i3. Implement autoleveling idea showed by @mjrice in this post. Pinion made for optical endstop.
On my printer, X axis homing in maximum position, so I make some changes in firmware, fix mistypes and stripout some unnecessary Z movements.
New code available on GitHub.
Video: one, two
Support not needed, because parts has inbuilt one.