I am using a precision micro switch to do depth setting. It is accurate to +/- 3 microns (this one D5A-8511). I am finding that my repeatability (is that a word?) is off in the Z direction by a thou or 2.

My method is to lower on the switch at 25 ipm until the switch triggers,
then back off in a rapid move .15 inches, then lower at 5 ipm until it triggers, save position,
then back off in a rapid move .15 inches, then lower at 5 ipm until it triggers, save position,
Take the average of the 2 positions, and set this as my height.

Sometime chips get on the switch which really messes it up, so I was planning to add a blow off nozzle, But then I got to thinking maybe there is a better way.

I used the switch so I didn't need to worry about adding a wire to the bit. With my ATC my goal is to let the machine do it's thing while I'm doing other stuff.

What is the best way to set depth? A different switch or a different method with the switch I have?