Touch probe inaccurate

Still new to my OF cnc but have experiance with my Shapeoko.
New for me is having a touch probe and love not having to slide a business card below my bit for z. :smiley:
But I measured my z thickness of the probe at 15.39 but after running the z probe the absolute value shows as 18.4. So when I ran the program it cut way 3mm too deep.
How can I correct this?

Probe dimensions can be updated in settings

You can also get @charleyntexas OF toolbox for $10 which has a program to measure the probe for you so you are 100% accurate. Then as Hermsen mentioned you can then enter those values into the OF controller so it has updated values.


@Fly_capt - as others have mentioned, it’s easy to correct in the SW settings. However, I’m not fully understanding the root cause. You measured 15.39mm thickness of the probe – check. You probed for zero with the machine, after probing, zero was set at 18.4 giving the 3mm error? So the thickness of the probe in the settings is 18.4 instead of 15.39? Just curious.


Did you probe for z only? You need to do that with the probe upside down and you probe in the recess of the probe.

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Yes probe upside down
After a full nights sleep and fresh start discovered, all is working as it should
The 18.4 absolute reading was on the screen before I started my cut. Turns out to be correct as after the probe the z retracted 3mm for clearance. Mystery solved

Not as comfortable reading the screen or functions quite yet but machine runs fine.
The cheap Makita knockoff I own, just lacks guts. Going to go buy a Makita and try it’s better.

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