Extruder stops mid print (and it's not jamming)

Hi. This is a problem i've having with my printer for some time, but having more important problems, and since it doesn't happens every print (it only happens in large prints of arround 4h and i have some sucessfull prints in between).

The problem is that randomly, the extruder (motor) stops mid print, so the printer continues as if nothing happened (heaters on, and head continue to move normally), but the extruder motor justo stops. No noise, no vibration no nothing, exactly like the Dry-Run mode. Except Dry-run mode is not activated willingly, there is no error not in the log nor in the LCD. When this happens the extrusor wont work again until y restart the ramps (turning off and on again the PS doenst work, since the ramps gets its 5v from the always on line on the psu and the US.

Motor and driver problems are probably not the case, since both the stepper and the drivers have been replaced (for an upgrade) and the driver has a fan blowing.

Any clue where can i start loocking? The absence of error messages got me clueless.

For the record, my setup:
Printer custom delta printer (based on a Delta-Six wich is based on a kosell)
Board: Ramps 1.4 with reprapdiscount full graphic controller (altought i'm printing from PC)
Drivers: DRV8825 (and i thing they are genuine, since my shop it's reputable)
PS: ATX PSU with 14amps in the 12v rail, and with a load in the 5v rail for balancing. (the heat bed it's mains power)
Host Software: Repetier (lastest)
Firmware: Repetier (lastest)

EDIT: the stepper is also not losing steps, in fact i can move it with much effort so it isn't powered at all

Edited 2 time(s). Last edit at 06/03/2015 09:04PM by javitopia.

Could be a bad solder or broken PCB-trace on one of the boards. Only occures when the heat slowly creeps in all corners of the PCB.
-Olaf

i'll try printing with the second extruder, altought since doesnt happens every print, it's a pain in the ass to troubleshot

I 've had the exact same problem when I thought I should give repetier firmware another try earlier this week...
Smaller prints do just fine.
Larger prints (e.g. 2h30m), at some point the extruder motor just stops turning and only works again after a restart of the ramps.
No clog or jamming.
I even changed my stepper driver to a brand new one. No luck...
And then I went back to Marlin: bam, problem solved. Well, marlin has its own set of problems but that's another story

Hmm..sounds like a wierd problem..It sounds to me like your extruder motor may be overheating...Check the trimpot screw on your extruder stepper driver...If its supplying too much energy it can cause the motor to overheat...usually after a couple hours of use...Another option would be putting a fan on the motor

The trimpot is adjusted to give sigtly less than the nominal current. And rigth now after a little more than a hour of printing, the stepper motor is onlly wam. I can touch it (and grab it) so i doubout the stepper is overheating. And from what i read the problem with over driving the steppers is that they will get hot, to the point they could melt plastic, specially PLA, and they could have their lifespan shorted, but in any case stop working (and it doesn't make sense that reseting the firmware solves it).

As for the driver overheating, if i'm not mistaken, it shut of for a small moment, wich lead to losing step, but this in the case of the stepper would only means a sigly understrussion, no a completly stop.

I'll tap a thermocouple to the stepper driver heatsink in the next print and i'll post the temperature, but i doubout it's getting hot.

Quote
swicboi
Hmm..sounds like a wierd problem..It sounds to me like your extruder motor may be overheating...Check the trimpot screw on your extruder stepper driver...If its supplying too much energy it can cause the motor to overheat...usually after a couple hours of use...Another option would be putting a fan on the motor

Nope, everything's fine there too. No motor heat, no over-current. Everything starts working fine after changing the firmware and *nothing* else...
I also forgot to note that the problem occurred with SD printing too (no host attached).
Oh, and repetier was 0.92, didn't check with 0.91.

Today it happened again arround layer 24 of a 4 hours print (and the stepper was barely warm) again, nothing strange in the logs. Isn't there any option to debug this?

However these days I've printed lots of small print (les than 2 hours) most of them continously and didn't have a problems so it's pretty strange, only happens with large prints, but anywhere in the print (that last one was arround 5 minutes until it failed). How does the firmware "knows" it's a big print and have a chance to mess it up? Could it be the sliccer?

UPDATE: the same print sliced with slic3r instead of cura and printed from SD failed but much later in the print

Edited 2 time(s). Last edit at 06/06/2015 04:56PM by javitopia.

The stepper will only stop working, when it has a winding shortage .
This would probably cause the driver to overheat and stop.

My humble opinion:
You have an electric problem, not a slicer problem. ( bad solder or cracked pcb-trace or loose wire )
The reason, why it happens on long prints, is purely statistics.
-Olaf

PS: You can force the error by pressing/twisting the boards while it prints

Have you tried replacing the extruder motor driver module, or turning the current down a bit?

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Both the motor and the driver have been replaced, also since the controller is different the current it's probably different.

Quote
javitopia
Both the motor and the driver have been replaced, also since the controller is different the current it's probably different.

That tells me, you don´t know?!

-Olaf

No, I'm sure they are different, since the old stepper and the new have different nominal currents, and I adjust the drivers 10% under that current (the old one was 1.5A and the new one is 1.3)

Maybe the extruder motor cable is broken somewhere and fails when the extruder carriage reaches specific height?

It's a delta printer with a bowden extruder, so being the extruder stationary, it's pretty unlikely however I've tried to wiggle the cables while measuring the resistance and there is no change al all

Did you solve this issue? If so, can you say what you did to solve it? I have a very similar issue but with Y motor. It just sudenly stops and a restart is needed for it to come back.

Edited 1 time(s). Last edit at 10/25/2015 07:38AM by GuzZzt.

More or less, unfortunately i wasn't able to use my printer very much since i started troubleshooting this error, but it appears that is related to the LCD part of firmware overwritting the dry run bit. It appears to be solved using a specific version of the lcd library. You can see more at [forum.repetier.com]

Having said that, it's pretty unlikely to be related to your issue, since dry run mode dosn't affects the axis motors, so i recomend you open a new thread for your issue.