Hey I’m super curious if you ever got anywhere with this? I feel like adding a z height adjustment for the endstop in the ramps firmware is probably very doable.
I also think that embedding the penny into your table also wouldnt be that hard, since it is a CNC and all. You could just cut a hole the perfect size for a penny and then glue it in there. Wires to the side or bottom.
And on another node, I’m curious if the bit of the dewalt 660 is grounded to the AC power supply ground or something like that. How cool would it be to check for conductivity against ground and not have to attach some connector to your bit every measurement.