CM - Better handling of G02 & G03 errors

If CM sees a G02 / G03 error, AND the GCode is in inches (more specifically, that G20 is active), then recommend to the user to resave in mm instead.

From what CAM program /post processor are you seeing arc errors?
But yes, #justUseMetric


Wasn’t me personally, it was someone on the Shapeoko user group.

It’s come up a few times I’ve seen, each time the answer is ‘use mm instead’.

From the post description, it looks like CC + CM.
Edit - it’s not CC, bad guess on my part.

Current versions of Carbide Create don’t export arcs, so this problem doesn’t apply unless one is using 3rd party software — if we did export arcs, I’m pretty sure we could manage to get the math right so that the problem wouldn’t come up.

As opposed to using metric, a better fix would be for folks writing CAM software to get the underlying mathematical calculations done w/ a correctness and mathematical precision that this error wouldn’t arise.


I’ve seen the issue over the years where Motion different like an arc that passes grbl’s checks. Not sure if anything’s changed related to that.

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Ran into this 20 years ago with BoobCad. Had to write my own gcode processer to read and correct their inability to handle single precision rounding. The software was neither cheap nor at the level it needed to be. The only good thing was that their password algorithm was a linear relationship with your computer serial number :wink: No surprise there. If an arc caused them issues, higher order polynomials would have been a disaster.

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