Extruder stops mid print
Hi,
I just installed the mk2.5s mod on my printer and the print quality is fantastic except for one major issue.
After a little while, the extruder just stops extruding. (the height is different on all 3 prints)
The printer keeps on doing all the movement as if it was printing, but nothing comes one of the nozzle.
I would expect some big spaghetti ball on top of those prints but there is almost nothing. maybe a tiny bit of filament but nothing really.
I just remove the print from the bed, hit print again and it just works normally.
Anything has any idea on why it would do this?
Re: Extruder stops mid print
The break seems pretty clean, so you might be suffering an electrical problem: a broken wire when the extruder reaches that level. Have you watched the extruder temperature when this happens? You can test by preheating the extruder when low, then raise it slowly a few mm at a time, and see what the temps do. Or print a small tall part and watch temps.
If the extruder is maintaining temp, you may have a heat break jam, or even a nozzle jam. Do a cold pull and then remove the nozzle - once opened up, blast compressed air up through the heat break. This will remove any loose dust that tends to collect in the heatbreak and PTFE tubing.
Re: Extruder stops mid print
Thanks for the quick help!
❗ Quick info after running a few more prints: When it stops printing, i can hear the extruder try to push filament down. It sounds like its clogged and it keeps on pushing filament.
➡ I used to have PETG in the printer and im now printing PLA, so i heated the extruder to the PETG temperature and unloaded the filament once the PLA stopped leaking from the nozzle because it was too hot. Running a new test print to see if it solved the issue.
Hypothesis 1: you might be suffering an electrical problem
This seems the most plausible cause. But i am unable to prove it.
The height isn't always the same, the LCD still displays the temperature and, without moving the Z height, i can do a filament unload.
Hypothesis 2: you may have a heat break jam, or even a nozzle jam
It seems to be a jam, but it solves itself once i start a new print. I don't understand how it's possible.
Both benchy stopped at the exact same height, but that height isn't the same for the other prints.
The picture isn't perfect, but i wanted to show how the height on the 1st print and 3rd print isn't the same.
And i actually managed the print the top when the print's height was smaller.
Next step:
- Print in the previous PETG filament to make sure its not cause by a PETG residue.
- Chat support recommended using some thermal paste in the heat break.
- Try to wash inside of the heat break.
Re: Extruder stops mid print
It is unlikely the PETG happens to plug at the same level multiple times; but loading PETG then doing a cold pull should fix that issue.
An electrical problem will be visible as you print: the nozzle temp will fluctuate and drop below 190c. Wires do break and become intermittent, where one minute they are okay, the next the temp drops; and a minute later the temps come back. A bad heater element can do the same - and might be likely to fail at the same height in a particular model; though a broken wire can also do this.
Another thought: you're printing what looks like Galaxy Black Prusament. The filled colors have caused folks printing issues like this, I fought Mystic Brown for a while, and often raising print temp to 230c will help get through the rough spots.
And a last idea is a heat break jam. When I've had them they are amazingly consistent ... everything works well, but suddenly mid print the nozzle stops extruding. Try a manual extrude after the print fails and it works just fine. You'll need to remove the nozzle (follow the instructions and heat the nozzle to 280c before trying to loosen the nozzle; same for tightening it back to 3Nm). But pull out the nozzle, blow compressed air up the heat break to clean out any accumulated dust and debris.
Re: Extruder stops mid print
As always, amazing feedback. Thanks for your help!!
It is unlikely the PETG happens to plug at the same level multiple times; but loading PETG then doing a cold pull should fix that issue.
This is my next test for sure.
An electrical problem will be visible as you print: the nozzle temp will fluctuate and drop below 190c. Wires do break and become intermittent, where one minute they are okay, the next the temp drops; and a minute later the temps come back. A bad heater element can do the same - and might be likely to fail at the same height in a particular model; though a broken wire can also do this.
If it really came back to temperature right after, i should see some spaghetti? It's just printing air and i can hear the sound of filament trying to be pushed down.
Another thought: you're printing what looks like Galaxy Black Prusament. The filled colors have caused folks printing issues like this, I fought Mystic Brown for a while, and often raising print temp to 230c will help get through the rough spots.
Maybe i'm assuming its height based but its actually based on the time printing? All 3 benchies jammed at the exact same height.
Both stand didn't jam at the same height. The first one jammed at 3/4 of the print.
The second one jammed a bit under 3/4 but i increased the infill density % for the last 1/3. It might of jammed after extruding the same amount of filament!
I also managed to print the top part of the stand so its not jamming because of a weird pattern. If its only the top part its either printing fast enough to avoid the jam or its not high enough.
And a last idea is a heat break jam. When I've had them they are amazingly consistent ... everything works well, but suddenly mid print the nozzle stops extruding. Try a manual extrude after the print fails and it works just fine. You'll need to remove the nozzle (follow the instructions and heat the nozzle to 280c before trying to loosen the nozzle; same for tightening it back to 3Nm). But pull out the nozzle, blow compressed air up the heat break to clean out any accumulated dust and debris.
It looks like this kind of jam but i don't understand why i can start printing right after..
After removing the nozzle:
Do i let it cooldown before pushing air?
Do i blow air from the top or from the bottom?
Edit:
Just did 2 cold pull with orange PETG.
Really scared to break the filament so i wont do any more pulls. Id probably have to buy nylon to do it.
Re: Extruder stops mid print
The second pull in your photo is near perfect; I'd consider the nozzle clean and not bother with a PETG cold pull.
If you have been hearing clicking at the extruder, that amounts to running your filament through a grinder - chips and dust flake off and fall wherever gravity takes it. The PTFE and heatbreak are the next stop. Dust in the Bondtech gear feed area is a sure sign of grinding.
To clean the heat break, I unload the filament at normal temps, then heat the nozzle to 280c, pull the nozzle while hot, and then blast air upwards (and down too - anything to clean the path). Then if the nozzle looks good I'll quickly reinstall it and torque it down. If the nozzle is looking ragged, I'll swap in a new one or rarely try to clean the old. If I do anything that takes time I turn off the heat. Reading suggests 280c for a while will kill the stock thermistor. Once I've replaced the nozzle I do a Layer 1 Calibration.
Keep in mind 280c is pretty darned hot, you don't feel the burn until after the damage is done, and the heater heats up tools quite well, too. I use a crescent wrench on the flat ends of heater block and 7mm socket on the nozzle. The heater is live, and wires exposed.
Whenever playing with the nozzle, also make sure the HEX portion is above the aluminum and not making contact: the nozzle tightens against the heat break, not the heater block - otherwise you'll get leaks.
If cleaning the heat break doesn't fix the issue... it's down to something electrical.
Re: Extruder stops mid print
Good news! Thanks to you, i got a full print!
Now that i can fully print, i have to look into those small imperfections.
❗ The following picture is PRE fix!!
I'll try to re screw the pulley on both axis.