Some of you folks probably already saw this idea, but is new to me.
There I was, wasting time cruising YouTube (actually it is only a waste of time if you are watching what the celebrities are doing). I had seen CNCNutz before but it has been awhile since I watched him.
He has modified the macro used in Mach3 and UCCNC so that a nominal material thickness can be input. He explains it way better than I can so you might want to take a look.https://www.youtube.com/watch?v=F1fpdYbBFfI
I run Gerry's (Ger21) ScreenSet 2010 so I downloaded the new macro and then modified it using some of calls Gerry makes to DRO's to get values. Not much really. I also changed it so it did not wait for me to touch the plate to the spindle before beginning to probe for the surface. I do not work that way, when I am ready to touch off I just put the plate under the spindle so there is no need for me to touch it with the plate. I also removed some of the delays he has built in to suit his style of operation which I don't use.