Autoleveller

I have a 6040 cnc using mach3, and I'm running into a weird issue.

When I start probing all seems good for the first couple touches, but suddenly it stops detecting and pushes into the board to the maximum probe height, if I let it continue it eventually goes back to probing normally but the final result isn't levelled at all, cutting very deep into the areas where the probing failed. You can check on the picture a board where I tried multiple probing grids and configurations.

https://imgur.com/a/ZcbV7s1

I am purely guessing, but have you checked all of your connections including solder joints. Sounds like an intermittent connections somewhere in your system. Also check your wires to make sure they are not broken internally.

Just a guess on my part.

As mentioned in the post, when the probe [mill] touches the PCB surface, the digitize input in mach3 lights up, and it works a 100% of the time, so doesn't seem to be related to physical hardware.

Are you using a USB controller? For some, the digitize light comes on as normal but probe commands in GCode behave erratically.