Ender 3 V2 stops extruding in the middle of the print

hi! I’ve had this printer working perfectly and printing 100% for the last 2-3 months and lately it’s doing this:
Im trying to work with a larger model, probably the largest so far. It’s actually 4 figures arranged on the base
In the middle of the print, aprox 1cm above Z=0, the extruder seems to stop working. I never get it while its happening, I come too late, so what I come across is the model halfway unfinished, the printer still moving, not realizing it’s out of filament, and when I cancel the job, assuming there was a blockage, I reheat the nozzle and I can easily pull the filament, load a new one, it fuses perfectly and drops under the nozzle, etc.

The filament I take out is totally eroded/bitten by the extruder gear, looks like it’s been trying to push it but as it was stuck, it damaged the filament.

I want to believe the hot end has cooled down abruptly in the middle of the print. Is this common? Probable reason?

Any other idea of what could cause this?


1 Like

Extruder gears too tight/close together? What size retraction and how many retractions maximum settings?

Thanks but I haven’t touched anything and it usually prints perfectly and smooth.
Retractions setting are just what shows up on default for “Standard Quality”…and this is something I’ve never toched.
It has to be something that changed in the printer itself…
Could it be a loose wire in the nozzle wire? Would it throw an error?

Ok it has to be the design or the gcode.
All the times it was failing it was a combined design of 4 parts: 1 castle, 1 car, 1 boat, and 1 gun, all designed by my class students
All the times the wire got stuck right above the boat hull. Then I separated the design and printed the gun, the car and the castle separatedly one by one, they all printed well.
Then when I went to print the boat, by itself, the problem happened again, right abve the hull the print was interrupted with the printer not realizing that the filament was not going thru and finishing with an ok-print-complete" message. This is the design of the boat: 3D design Spectacular Densor - Tinkercad
It was taken to Cura to generate the gcode with proper supports, etc…

What could be wrong?


Had a look at the boat and it doesn’t like slicing the “railing” round the deck, presumably it needs to be a bit chunkier. It completely ignores the rigging. This is in Cura 5.7.2. Also ran it another slicer with similar results. I would thicken the railings and rigging.

Mmm sounds interesting, I will try that, but the fact is it doesn’t look like it ignores the rigging like it wasn’t there, in which case it would simply stop the extruding of the filament, but in my case it always destroys the filament like it keeps pushing filament and, this is my guess, the hotend gets cold and it can’t push thru so the filament gets stuck not being able to flow out
BTW I’ve always checked and there’s no actual blockage, as soon as I reheat to 200ºc and manually turn the extruder knob, it flows out of the nozzle easily


Update. I printed the boat again some days ago but this time I rotated it sideways, leaning on one side. This also helped to create less supports.
It printed well with no issues. Well yes the rails and rigging were too thin to withstand removing the supports but that was expected…
I assume the problem was something specific with the design that either the slicer (btw Im not using that version, Im using 5.6.0) or the printer, had some problems with