CoreXY, weird movement in Y when I move in X!
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.........and check all the grub screws on your pulleys. It sounds a bit like one pulley is slipping on the motor shaft. To get either pure X or pure Y on a CoreXY, then both motors (and pulleys) have to turn an equal amount, either in the same directions or in opposite directions. So if you have some movement in the Y direction when doing a pure X move, then one motor or pulley or belt is moving further than the other, and the most likely cause is a mechanical issue.
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..........and 10,000 mm/sec^2 is very high acceleration so you might be getting skipped steps. Try 1,000 and see if that helps.
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the config looks fine. as @deckingman said it is most likely a mechanical issue.
i would slow down the movement as low as possible and while its happening check every pulley.in the video from 0:45-0:47 you can see the belt lowering by itself. that should not happen.
As far as i understand the white belts have steel cores that do not bend very well. this could be problematic. -
I, too, suspect a mechanical problem, specifically related to using steel core belts on small pulleys. It takes significant force to bend the belt around a (small) pulley. Moving in Y requires that each belt bend around 3 pulleys. Moving X requires that each belt bend around at least 5 pulleys. Maybe the motors are running out of torque, maybe the steel core wires have broken inside the belt(s) somewhere.
Steel core belts and small pulleys are a bad combo- the belts will not last because the steel core wires will break due to repeated flexing. If you must use steel core belts, you must also use large diameter pulleys if you want the belts to last.
Try installing glass core belts. They are much more flexible and easier to bend around small pulleys. The cores will last a long time without breaking. If you're worried that they stretch, use 9-10mm wide belt. They don't stretch enough to matter, and your printer will be much more reliable.
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All grub screws are tight and good.
tried 1000 mm/sec^2 same problem.
Doesn't matter the speed I choose, nothning changes.
All pulleys are smooth and good.
All belts are in correct place in pulleys.
Not a motor torque issue (tested).
Will try normal belts instead of my steel core belts. -
Thanks guys! Problem is solved. Replaced the steel-core belts with normal belts and the problem is solved!
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@RajaaKahel Glad you got it fixed. For info, I use "normal" 6mm wide belts and throw 3Kgs around on one of my gantries. Never had a problem with stretching or breaking.
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@deckingman
Thank you.
Good, I'll stick with normal 6mm belts for now then..
Strange, these steel core belts were working fine. -
@RajaaKahel As @mrehorstdmd alluded, steel belts need a wider bend radius so they may have worked initially but then one or more of the steel cores could have broken when being bent around a small pulley. This then enables the belts to stretch.
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I put some of them on a delta I built for someone Had to replace them within 2 weeks as the cores snapped causing the belt to stretch by at least 2 mm strange this was (Well not really strange) it was all in the same place.
