That should work. The post/extrusion routine assumes the object being probed is symmetrical (which a sphere is).
Are you trying to find the center of the sphere in XY? If so, you don't have to set the extra depth to the major diameter of the sphere - you can just set it some convenient depth - since the sphere is symmetrical, probing a any constant depth will give the XY center.
Dave
I need X,Y and Z but that shouldn't be too difficult to get. Just wanted to make sure I was on the right track.
Still getting random overshoots with my UC300 and C32 BOB. I have two machines that do the same thing. Every 15 or 20 probes it will overshoot. I'm at the point where I just keep my finger on the stop button while it's probing.