A simple "end" for a bolt that can be used to actuate the typical optoisolator found on an optical end stop. Need to make the nut hole big enough to fit a nylock (9.4mm worked for a #6 but barely on my printer). Use the customizer! Force fit the nylock into the hole (CA glue if desired) and tighten the striker bolt in. The only problem I see is that for a 6-32 bolt, you MUST go in 1/2 turn increments (so the striker fits in the slot) and that's about 400 microns of "step" -- not bad probably except maybe for the dimension over the bed. Haven't tried it out yet.