Is this type of loose belt play to be expected?

After completing calibration (yay!) I am seeing that when I begin to give move commands to the machine, the bands on the opposite side are a bit looser than I would expect.

Does this sound like expected behavior, or do I need to re-calibrate/repair something? Thanks!

I am seeing similar behavior, but specifically with my lower right belt. I’m in the vertical orientation, so the upper belts are always taut.

Just to confirm, which firmware version are you on?

0.70. Thanks!

I’m on 0.70.2, so updating might not do anything for you, but here’s the thread with the newest release. It’s more up to date than the github.

I’m going to run another calibration and see if that helps, since it should become more accurate after that, but I’m going to do a test cut first to see how much of a difference it makes for this on mine.

Aaron Richards wrote:

After completing calibration (yay!) I am seeing that when I begin to give move commands to the machine, the bands on the opposite side are a bit looser than I would expect.

The belts should not be loose, when you did the calibration, were the belts lose
as the measurements were taken?

note that if you needed to increase retraction current, you probably need to
increase the calibration current to match.

David Lang

I’ve seen something similar and specifically with the lower right belt. I think that maybe it has something to do with the z-axis height compensation code since the top left and bottom right arms are higher up.

It’s something that I’ve seen too and I’m looking into it so I don’t think it’s a you problem at all.

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I finished my calibration yesterday and received good calibration values. During calibration, all belts where taught during moves (toward the end).

When jogging, top left and bottom right spool out waaaay too much belt. I centered and moved diagonally from bottom right to top left which should have a matching amount of belt move but it spooled out almost double on bottom right.


Just had a similar problem with jogging left … went almost 6’ from center when it was set at 100mm!

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Mine moved a reasonable distance (did not actually check it) but it just spooled too much cable on the “push” side.

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We had a very similar “push” problem. On our recent calibration, other than the extra slack on the first 9 points, everything was smooth and tight UNTIL point 81. After 81, there was a major move from bottom right back to bottom center, and then back to middle. On this move ONLY, the bottom right arm spooled out a ton of slack. Thankfully we were watching it. First time through we pulled the power on it to prevent it from eating itself in a tangle. Second time through it did the same thing, but I manually arrested the pushing until it got into position.

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I’m having a hard time visualizing what that entails. Can you elaborate?

On the move from the bottom right of the calibration matrix to the bottom middle and then to the center (in point 80-81) it seemed as though the bottom right arm went into “extend mode.” As tension was pulled by the move it started to unspool rapidly.

The first time I didn’t notice until it was almost too late and it would have tangled.

The second time I applied pressure to the external side of the bottom right belt. Because of this, even if it was in “extend” mode, it didn’t extend rapidly because it wasn’t triggered by the consistent movement of the belt.

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