Filament stops extruding mid air, not clogged

[cblte]

Hello everyone. Thank you for the tips and tricks here in the forum. I have read quite some posts now but could not find a solution yet.

TL;DR:

I have checked the things other people mentioned. My prints are starting fine, and then at some point the extruder stops extruding filament, printing mid air without extruding. Calibration, pre-drying, external spool and AMS feeding was exercised. Please read to the end, this is the short version.

I am trying to print with https://www.3djake.com/3djake/petg-bronze which has been lying around for about 1year. I put it at 50º in the oven for about 5 hrs prior printing.

Settings used:

• 0.4 Nozzle 240º
• Speed: Silent (50%)
• 70º on the PrintBed.
• Profile: Standard 0.2mm

What happens is, that at random (4 tried yet) the printhead stops extruding filament and continues in the air without giving a warning. Out of the 500 Layers it stops at 50, 90, 240 and 270 (not in that order).

When stopping the print, the filament got cut, pulled back fine. When initiating a “Filamane load” the filament was extracted fine and everything looks good. I could even finish a print with another PLA filament which came out fine and nothing was clogged or jammed.

What I did recognize is, that the end of the PETG (which was pulled back) was visibly thiner than the 1.75mm it has.

I thought maybe a production failure so I slowly re-spooled the filament twice and checked carefully the diameter in front of a white paper, but could not find parts that are visibly thinner.

I have now changed the hotted from 0.4mm to 0.6mm and will try again. Attached is a picture of the 0.4mm hot end with some PETG bronze filament sticking out.

I have read

• TIP: Clearing extruder filament retraction jam - #2 by lion.nmn
• Problem extruding X1 - Stopped mid print, carried on printing nothing - #8 by jacepackard
• Tip : extrusion stop but nozzle is not clogged ? this can help - #4 by joachimS
• ERR: Failed to extrude the filament. Check if the extruder is clogged

I read, watched all of the above threads and more. Nothing is clogged and I can print different things in between.

So am am looking for solutions to fix this filament or maybe the model? I have no idea anymore except chasing the filament and throwing away this spool. Which would be bad as it was a 30 Euro one and should not be wasted like this.

While writing this, I am printing again a flow calibration with a 0.6mm nozzle which I installed in the meantime. Maybe this helps. I do not know.

Thank you for reading all the way up the here. If you had the same problem, please let me know and if you found a solution to yours, please also let me know.

[lion7718]

As simple as this sounds…random stops is usually a Bad SD Card…so try using another card.

[cblte]

Wait, what? So you say, because I was doing time-lapse recording, the extrusion just stopped because the time-lapse could not be written to the sd-card because of what ever issue the sd-cards has? Is it that what you are trying to tell me?

Do I understand that correctly?

This seems to be too simple but sort of maybe makes sense. What I do not understand ist, that the SD-Card is linked to the extruder. Everything else was still working normal. Movement, x-y-z axis. It was just that the extruder stopped extruding filament and the AMS was not pushing.

---

I will try again without auto-monitoring and without time laps. then I will get a new sd-card. Still using the original one but will replace with a good Samsung Evo.

Thanks for the hint as this would probably be the last I could think of.

[NeverDie]

If that doesn’t work, then for diagnostic purposes it should be easy enough to switch to a different brand of filament just to see if that by itself clears the problem. It should be easier to do that than to search for a fatal flaw in the filament that’s already mounted.

Also, you didn’t mention layer height, but if layer height is too short, it could conceivably produce the effect you described.

[cblte]

Sorry, you are right, forgot to mention the layer height. I was printing the standard 0.2mm Profile from within BBL Studio.

If the stupid filament still does not work, turned off time-lapse and auto-monitoring, I will try printing with another PETG/PLA filament.

[cblte]

Update: After chaning the SD-Card and formatting it through the printers menu, everything seems to work fine. The solution probably was a failing SD-Card. What a strange thing that this is not handled by the printers OS in a better way.