Oh, that would be a great option I think. When I was just scratching I looked at using center punch mechanisms, but couldn’t find something that worked. Wegstr has diamond engraving bits that are spring loaded, I imagine those would work. A little pricey but I can’t imagine the diamond wearing out any time soon :). I’ll try ordering one, I was going to get via rivets there anyway.
Another option might be putting the springs in the work holder. I’ve tried scratch only boards with the PCB fastened to the top of the rivet nuts (I drilled the holes too small), and it worked ok. The board naturally flexed a little in the center, but that didn’t effect the results. Maybe even something like a weak spring washer around each post, and then the PCB holes slightly oversize to allow up and down travel. The only question is the side to side potential motion of the board, and if it affects the drilling (those bits are very sensitive to lateral motion). I should be able to try this with things on hand, I will let you know.
Thanks for the ideas! I would love to get rid of the auto level step too, not just because of the machine mods, but it’s also the only reason I use bCNC as well (which is a great program in the end, but hard to get used to).