Thanks Brian. Anything that makes it clear how the probing works and minimises the possibility of damaging the probe would be great.  Different people will have completely different ideas about probing. My interest is probe functions like several of those provided with the current Mach4 4 axis mill profile. I probably wouldn't use the measuring functions but probing to find edges, corners and centres is why I purchased a probe.   I am a new hobbyist with no other exposure to any CNC so not in a good position to offer much in the way of suggestions other than comment on what has tripped me up and contributed to damaging my new $750 probe.  It wasn't till after damaging my probe and spending a few hours going through the probe module LUA that I really understood what was happening so I didn't repeat the crash.
Keith

I don't know how this is going to end but I can tell you that Steve, Tom and I are looking at how to redesign this better. I expect to have a sample mid January. I will post here on the forum for testing when we have something working.