CoreXY intermittant 45 deg. layer shift on larger prints
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@zapta said in CoreXY intermittant 45 deg. layer shift on larger prints:
@dlc60 said in CoreXY intermittant 45 deg. layer shift on larger prints:
the Y axis always stops short of home. The cancel.g file says it should have homed both X and Y...
By 'homing', do you mean actual homing with end switches and such, or that you just tell the head to go to a certain (x, y) and the y position doesn't seem right?
I mean "go until you activate the end stop switch". What is weird is that it simply doesn't get all the way home, but stops.
DLC
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@Phaedrux said in CoreXY intermittant 45 deg. layer shift on larger prints:
@dlc60 said in CoreXY intermittant 45 deg. layer shift on larger prints:
0.4Amp
Are they really 0.4a? That seems incredibly low even for a very small printer. Do you have a link on the motor specs? Target 60-85% of the motor rated max current.
Do you have the Maestro actively cooled?
the Y axis always stops short of home.
This could be due to missed steps. If it's actually running a homing command here, you can change your homing macro to increase the distance the axis moves towards the endstop and see if that fixes it after it's done some layer shifts.
The advert title was totally whack. This is the stepper:
17HD48002H-22B Nema 17 Stepper Motor 1.7 A, 0.59 Nm and I am driving them at 1.0Amp. There should be plenty of muscle there. However, I tried driving them at 1.3Amp and they got hot pretty quickly. Quicker than I would think a 1.7Amp spec should.DLC
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@pandaym said in CoreXY intermittant 45 deg. layer shift on larger prints:
Have you seen my thread? I had the same sort of thing happen yesterday. I think I solved it now with upping motor currents to 75% of motor rating.
That might work, I tried that though and shut it down because the steppers got very hot by the time it was 1/3 through the print. It didn't seem like a good idea.
DLC
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Unless it was over 80c the steppers probably didn't mind.
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@PDBeal said in CoreXY intermittant 45 deg. layer shift on larger prints:
@dlc60 said in CoreXY intermittant 45 deg. layer shift on larger prints:
Then I started to get intermittent 45 degree layer shifts toward the "back right" stepper, which I will call the "Y" stepper since that is the port it is connected to. When this happens and I cancel the print, the X axes homes, the Y axis always stops short of home. The cancel.g file says it should have homed both X and Y.
Since you mentioned the Y axis stops short trying to home, what's your homey.g file look like? Are you sure your homey file homes the y axis through a length greater than your actual machine maximum?
Do your steppers have cables coming out of them or are they connectors with cables plugged in? If you have connectors, its possible one of those is loose or not making good contact?
The wires go directly into the stepper. Hmm, I didn't look before at homey, homex. That would tend to support the thought of missing steps.
DLC
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@Phaedrux said in CoreXY intermittant 45 deg. layer shift on larger prints:
Unless it was over 80c the steppers probably didn't mind.
It was more like 50, by my calibrated finger tips... Heat like that might shorten the life span of the motor by a bit. Still, if nothing else works, I will try that again when I can keep an eye on the system all the time, just in case.
DLC
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@DIY-O-Sphere said in CoreXY intermittant 45 deg. layer shift on larger prints:
@dlc60 said in CoreXY intermittant 45 deg. layer shift on larger prints:
Does anyone have any other ideas?
Try to turn off StealthChop for the X and Y drive.
You can do that by adding a D2 option to the M569 code.M569 P0 S0 D2
M569 P1 S1 D2It's a common issue with the maestro.
In my case that had solved the problem reliably.Sadly, this had no effect at all.
DLC
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I was actually able to be right there when the problem happened this time. The hot end was striking plastic, like the Z had not dropped to the next level.
This is a completely different kind of problem. I wonder why it always shifts the same direction? Maybe that belt is looser or that stepper is just a little weaker...
This is why my exercise program showed no issue, it drops the Z about 5mm and then jams the X/Y directions around. I need to add a Z movement section to the test.DLC
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Much strangeness.
I swapped X and Y steppers and saw the shift move to the other diagonal, which implies that it could be related to the stepper motor. I also found that my Z platform was not flat anymore, one side was off by 2mm, so I re-trimmed the screws and re-leveled the bed and started another test. On the second layer of the next test, when I wasn't looking, I heard a loud "bzzzt" kind of grindy, buzzy sound and the layer shifted a huge amount straight towards X0, no diagonal at all. The Z had already moved and about half of the layer had already been printed when this happened. While the motors were all powered I tried moving the X/Y carriage, and I could move the (now) Y motor, but not the X. It looks like I may have found my problem. I should not have been able to move that stepper pulley with a court order, but it moved when I turned it with my fingers, that shouldn't be. Since my shift moved when I swapped the steppers, that means that bind was not in either belt circuit, it is in the motor. I have a new one from the seller coming, I just don't know when. Or, hmm, move my Z motor to Y and get another stepper from the junk box for Z, it does not have to match the other two.This story just keeps changing...
DLC
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@dlc60 50C is stone cold for the surface temperature of the motor. They can easily run 60-80C for the surface, without noticeably changing the lifespan (80C keeps the windings below 120C, probably, which is their full industrial-lifetime rating in low-temperature motors, typically). I tend to run a surface temp of around 60C under normal, fast-ish printing. During my print run making face shields, I upped my motor current to 80-90% of spec, so I could run faster. Surface temp was then about 70C. If the motors eventually die, tough luck, but they are designed for this.
I have a personal philosophy about tools: they are meant to be used. i don't abuse them, but I use them in a way that gets work done, and if it wears them out, they are doing what they should.
