This is a similar probe like design as on a CMM OR CNC Measuring machine.
Working with these machines i thought it be cool if my printer also would work with a probe.
I added 2 bracket files,one without and one with holes for the end stop. I printed one without holes and drilled them. The one with the holes is not tested.

the bracket thats holding the rod has 2.8mm holes that i've drilled to 3.1mm for the rod.
The rod is a 3mm carbon fiber rod with a 6mm bead that i glued to the tip. Between the two holes there is a small clip thats been glued on to keep the rod from falling out. the clip is glued closer to the lower hole. (See photo attached.)