Test cuts in calibration .. measure .. retest cut .. distance do not close

As I understand this calibration process … you should run a test cut … measure the result and load it and then rerun the test cut and the two numbers should come together gradually.

Mine bounce around but never get close.

1st H 602 V 593
2nd 601.5 594
3rd 601.5 593
4th 602 592

This can not be right … I have re-calibrated everything else .

I am lost on this one.

Also running a 45 degree pantograph linkage design but that would not seem to matter

I changed to Triangle and measured and input the end of chain to center of the router bit in advanced settings.

I wonder if the calibration routine accommodates the triangular Kinematics? The test cut routine adjusts the distance between sled mounting points for the original setup, not sure what it would adjust for the triangular one.
This sounds like it would be good to open as a new issue in GroundControl. Would you do that?
With all the recent interest in alternative sled connections, we may well more of see this soon.

Thanks I will do that as well

1 Like

Thanks for opening the issue.
Another thing that can cause this problem is when the motor arms are being pulled together by the chains. Use a tape measure during the calibration step, before and after releasing the chains, to assure that the frame is properly stiff.

You are talking about the 45 degree arms with the motors attached …right?

I think the while frame needs some stiffening and am working on that. So I will make sure they are rigid.

1 Like

I think @blurfl called it, the automatic calibration routine won’t work with the new triangular kinematics yet. The best way that I found to calibrate for the triangular kinematics is to make three marks that fall on a straight line as far apart and close to the top, then adjust the motor spacing until they all come out straight (basically the line they fall on isn’t curved up or down). I will need to automate that process

1 Like

Do you find the best value is the true measurement, or is it slightly different? How do curve-up/curve-down map to increase/decrease the spacing?