Calibration Issue - Low Center

Good Afternoon,

We are trying to calibrate our new maslowcnc but have run into a problem. During the calibration, we did all of the measurings and was starting to do the cut test, unfortunately, our center is a bit low, so the CNC ends up past the bottom of the cutting board

Any ideas how to fix this?

Welcome to the Forum!
Do a sanity check on the values in the GroundControl settings.
Motor Offset might be off.
Try to enter values that you measure by hand and do the calibration again.


I just checked all the measurements and everything looks good. I am not too sure about the Motor Offset height, “Edge of the work area to the level of the motors” isn’t a great description…

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The calibration process adjusts the “motor offset height” value as part of the optimization process. So if you change it to make cuts higher on the board and do another calibration, it might (and probably will) go back to your previous value. However, if you don’t calibrate it, you might suffer some accuracy because chain sag and rotation radius (the other two values optimized) were determined based upon the motor offset height that the calibration came up with. I hope that’s not too confusing.

I’m having the same problem.
V1.23 of Firm ware and GC

edit - Using the Supplied Ring for the Chain connections to the sled, Chains Off the Bottom, triangulation.

went through all the steps. made the test pattern, entered the measurements.
Horizontally it’s right on Center.
But Vertically, it’s low by 13.76"

I made a Bunch of test moves, and every move looks to be very close to the correct distance.
Cut an 18" square that with a tape measure isn’t off by more than a 32nd of an inch.

But the Center location is still Low by 13.76"

What I did, was Move the Sled to Where it was on center vertically.
I then Marked the Links that were on the top of each motor Sprocket.
Then I sent the sled back to Center.

Now I unhooked the Chains on the sprocket, and put the Link I marked back on top of the Sprocket.

Now GC thinks the Sled is on Center, and by relocating the chains, the Sled is Physically on Center.

re-ran the test Square and the size and position is correct.

So I thought OK…
I’ll run the calibration test Pattern agin, the 4 vertical cuts and the 5th horizontal cut.

took the Measurements and Plugged them in…

And Now my Sled is 4.5 inches too low.

this time, the Sprocket is just out of rotation so that the Chain Link I had Marked, isn’t exactly on top.
If I do the same thing and Move the Chain so the Marked Link is as close to top as I can get it.
I’m about .25 inches Low.
If I go One link more, then I’m about .125 too high.

Is there a Setting that can be adjusted so you can Adjust the Vertical Center.

You can move the sled and Call that Home…
but I can’t find any where to move the sled, and Assign that as the New Center.

My test Square is still dimensionally correct…

Only my Center height is off.
And every time I re-run the calibration, It’s spot on horizontally, but the Vertical is always off ( low )

Would be Nice to just Measure how far off it is Vertically, and just plug that number in as an Adjustment
to get the sled on center vertically.

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You can do that! The setting for the distance of the motors above the work area will just translate everything up by the amount you change it.

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But the fact that it’s not going to the center probably indicates that it things
something has the wrong dimensions (motors too close together most probably) and
this will mean that if you cut across the machine, it’s not going to cut a
straight line.

David Lang

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