Calibration failure at test patten

Hello all, My calibration went smoothly until the end. My values for chain sag seem to fail the calibration. Any thoughts on where to go from here?

Hi there, can you upload the groundcontrol.ini from you user folder, or find the section in the log.txt from the GroundControl folder that reports the machine dimensions after $ symbols?
One of the 2 could give a clue of what your Maslow is thinking what size it is.

1 Like

Sure thing, here is the ini From what I can tell the bed height and width are correct at 1219.2 and 2438.4


That was fast :slight_smile: I’ll take a look.

Nothing unusual on first sight

bedwidth = 2438.4
bedheight = 1219.2
Your ply sheets are slightly smaller then mine

motoroffsety = 419.0
Distance form a line between the motors to the top of your sheet. Is ~420 correct?

zaxis = 1
You have a automated Z-axis installed

motorspacingx = 2997.81
The distance between your motors I’d expect to 3m+

chainoversprocket = Bottom
Your slack-chain run across your top beam and not on the sides

kinematicstype = Triangular
rotationradius = 145.0
You are using the ring-kit-chain-mount

:wink: you run a Mac :wink:

If all of this is correct, then I would recommend

  • to shut GC down, disconnect and reconnect the arduino (com-port will/might change!)
  • restart GC and the calibration, skipping all steps until the test-cut and try from there

Can you delete the .ini again?
I got a bit paranoid after a watching a series of 35C3 videos.
Best to delete the path that has your computers user-name (not needed for troubleshooting) and upload again.

Thanks for the help, and good looking out!

Are you running FW and GC v1.25?

Yes I am

1 Like

I’ve found that this could happen in the event that for initial parameters the machine uses, the machine expects that measurements for Cut 1 be shorter or longer than for Cut 2, but the measurements entered are opposite of what is expected. So if the machine expects Cut 1 to be longer than Cut 2, but what’s entered is that Cut 1 is shorter than Cut 2, it won’t find a solution and will give you an error message. I’m not saying that this is what happened here… I just always recommend that for this step in particular, you double, triple, quadruple check you measurements.

1 Like

Does that mean that the g-code for the test-cut intentionally tries to make cut1 shorter then cut2, or where dose the expectation come from?

Think I got it, expects to be within a range +/- something

Well, maybe my wording isn’t the greatest and a bit inaccurate and my brain is focused on something else at the moment (sorry) I’ll try to organize my thoughts later and rephrase all of this, but just suffice to say, double, triple, quadruple check the measurements.