Anyone using probes and or camera to find center?

Yes, my camera plugin might help with this problem. You have to decide on the center of your workpiece. But wherever that is, you draw a mark on the center. What Paper Tools will do is then move your router over the square, it uses computer vision to find it and I’ve gotten repeatability of +/-0.002. Then you can zero your machine over that square and begin your cut.

Here’s a post that talks more about it:
https://forum.avidcnc.com/t/mach4-plugin-try-out-my-visual-cnc-plugin-and-give-feedback/1990