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hello guys,

I’ve been having some issues after upgrading to a MKS v1.4 board with TMC2100 drivers. While retracting my extruder stops working and only starts when the i plug the power in again. It keeps working for 10+ minutes when I disable retraction, therefore I assume it is not overheating. I’ve tried lowering the current which didn’t help. I also switched 2 drivers to see if it was a driver related issue. It should also not be a mechanical issue because my old board worked fine before. I’ve attached a video showing what i mean.

https://www.youtube.com/watch?v=1hx6RPyzo1c

as you can see the gear isn’t turning after printing the skirt. also there is a loud noise the moment it stops working.

if you have any suggestions, please let me know.

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I have/had a similar problem with my delta. I ended up turning the retraction speed down to 30mm/s. Mine would still print fine just wouldn’t retract correctly for some reason if I have it faster than 30mm/s. It would just squeel like yours. I still don’t know what the root cause is, I just know this works for me.

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What was the result after switching the drivers? Same? Then maybe the pins of the board where the motor is switched in should be checked.

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after switching the drivers it did the exact same thing. i’ve also tried the same driver on the second extruder slot on the board which also did nothing.

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It looks like the motor stalled, possibly because the drive current isn’t high enough or the motor was not able to move as fast as the control pulses were telling it to. In practice, it’s almost always that there isn’t enough current going to the motor. I’d try turning up the current on the extruder driver IC, and/or turning down the retraction speed if you can’t increase the current. (You should be able to increase the current by turning a potentiometer that is connected to the driver IC).

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The ugly big sound during the retraction is a very good sign. It means your problem is fixable. Stepper motors are like shoot and forget devices. It doesn’t give feedback to the control board if the motor actually turned the gear. Hence the burp sound.

The scew that holds the small gear to the motor is loose. Make sure the small gear is not broken. Tighten it and your problem will be fixed.

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I’m at 30 mm/s already, that was one of the other things I tried. I really don’t wanna go lower, because that means the nozzle will be on the surface too long, causing blobs. Thanks for the suggestion though!

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I have turned up the current to the maximum already. and since I also tried lowering the retraction speed to 30mm/s. I really don’t wanna go much lower than that because it will cause the nozzle to stay on the print for too long.

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the part about the no feedback I understand, the thing is though shouldn’t that mean that after the failure to retract the motor continues to run? Right now the driver kind of shuts off, and after the failure I can easily turn the driver with my hand meaning the driver is disabled. which led me to believe the over temperature protection triggered. Ow and the small gear isn’t loose i’m 100% sure, I checked.

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Did you check is the driver overheating? I had similar problem and I noticed that the drivers were too hot. After adding bigger heatsink and a fan to cool them, all issies were solved.

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How would i check this? I tried lowering the current to check this, but it did the same thing. is there any other way? the heat sinks aren’t hot and I placed a fan on them already.

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You need to do testing with the hotend off (and the filament removed from the hotend) and see how the extruder behaves when you do a fast manual retraction. Break this problem down into its components: You know that it flips out when you retract, so isolate that problem and test the motor without doing a print. That will allow you to do things like adjust the current and see what the affect is, see if there is a force where it causes problems, or feel exactly how the motor acts when it flips out.

Also look at the temperature of the driver because it might be overheating.

The popping sound you hear may just be from the spring force of the filament slamming the gears together when the motor stalls. You also might have a wiring problem or a motor that is requiring too much current and during the fast retraction it’s causing the driver to get overloaded and shuts itself down.

Bottom line, isolate the extruder motor and test it independently of the hotend and see if you can manually reproduce the problem.

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Well, if the heatsink is installed with thermo paste/tape and it is cool, then probably is not overheating. If it start to run again after reatart, then it is some kind of protection. Try to dry run it, with no fillament. Try with different motor. Check the G-code or print some G-code that was printed before (use g-code not stl). Maybe, for some wierd reason, the slicer that you are using just stops the extruder when the raft is done. In general, you need to try elimimating all possible reasons one by one.

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The wiring is a good point. If they bend a lot, over time they are breaking inside. Had this issue as well.

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alright thanks for the reply. I have unscrewed the motor from the feeder, so it only runs its own axle and the smaller gear. It still flips at the same point. I assume that means that the motor isn’t stalling. as for the temperature the heatsink itself doen’t even remotely get hot. also the motor still makes a high pitched noise when retracting.

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The heatsink is cool(and the heatsink makes contact with the chip) therefor i assume the driver is not overheating. I tried using gcode to retract the filament manually. this gives me a different result, the driver does not disable itself, but but the motor does kinda “stall” this is not a mechanical problem however cause i can turn the motor freely when the driver is disabled. should i try decreasing the microstepping to check further. I think that with 1350 steps/mm i could go down to 675 and still be fine in terms of resolution?

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for the wiring i’ll check if i can measure the resistance from the connector to the inside of the motor.

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The motor should have connector on it. At least most motors do. You need to bend the wire while measuring, to wave it a little bit. Those kind of breaks are hard to find. The easiest way will be If you can replace it temporary for the test. Do this issue happen only on specific height or it is completely random?

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My feeder is stationary on my printer (bowden setup). it always happens on the first layer. all my steppers have connectors except my feeder motor sadly.

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Alrigth for now I think i have “solved it” turning down the microstepping fixed it for now. I will get back to you if it fails again.