Scale Issue

I seem to be having a scale issue in Easel. An object which should have carved at 2 inches wide actually carved at 10 inches wide. I toggled to MM in Easel and it carved the same size. I reflashed the Arduino this morning in an attempt to get my limit switches working… which I did… could this be a grbl issue with the new update? Does anyone have any advice?

Yes. Did you update your controller right before this change? What grbl version did you have? What version did you flash?

You need to readjust the step/mm values ($100-102)

Any thoughts on what should those values be? Right now they are:


Does that look right?

These IIRC is the stock Xcarve values:

$100 = 40.054 (x, step/mm)
$101 = 40.054 (y, step/mm)
$102 = 188.443 (z, step/mm)

This problem is exactly why you should periodically check your machine calibration and setup !!!

It sucks to find out something is off during or after a carve and waste time and material.

I find myself checking and recalibrating my machine at a minimum of once a month, whther or not I believe there is an issue.

More often than not, I have found an issue (loose v wheels, loose belts and bolts/nuts, spindle tram issue, etc.) when I would not have noticed it otherwise.


He has the M8 threaded rod.

Here are the defaults for the original 500mm X-carve with the ACME rod. ($102 = 320 for M8 threaded rod)

$130 and $131 are different for the 1000mm machine and vary depending on which grbl build is used.

Yes, but

$100 and $101 should not be at 250 (!) regardless of the Z Axis screw!

One of the reasons I linked to the complete set of default parameters.

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Considering that $100 and $101 are set to =250.000, I do believe this is your issue.

Those two settings control the distance traveled on the x and y axes (steps per mm) are about 6 times what they should be.

$102 is the same setting, but for the Z axis. If you have the M8 Z axis rod, then it is correct at =320.000. If you have the ACME threaded rod, then it is incorrect, and should be changed to =188.443 (final value also depends on stepper motor used and default divisions setting).

I would try to do a $RST$ for GRBL, and see what the default values load back into the controller first.
Then I would re calibrate the x y and z axes properly.

What do you think @LarryM?

In theory a good plan, but one still needs to be careful as Inventables builds were not careful, at first, to update the defaults as the machine matured.

I would follow the suggestion that you made, having first saved the current parameters in case the firmware installed does not have the correct values in the build.

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