3 d filament snapping mid print

[Nick]

Hi,

I'm having issue with my CR10S filament snapping mid print. Mutiple different filaments used with same issue. I've replace the bowden tube, cleaned the extruder , cleared any filament from the hot end and changed nozzles. The only thing I havent done is take apart the hot end to took for build up inside. Maybe heat creep? Its been really cold as well, that could be a factor. It starts our fine prints for a file then either snaps or sometimes it will stop extruding.

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As a additional note. I have a Tevo tornado using the same filament and in the same cold weather and its printing fine. I have a CR10 in another room and its printing ok.

[TommyDee]

Where is the filament breaking... in the bowden tube or pre-filament driver?

[Nick]

Thanks for the reply. I have 2 printers its happening to. The CR10s is snapping outside the tube. But the filament inside the tube is really hard to pull out almost impossible.

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I had a lot of failed prints when I first got the printers. There was a ton of gunk and build up everywhere. Not sure if I needs to maybe clean out the hot end.

[TommyDee]

Well, PLA does snap like a twig when it is past its prime. Some are actually formulated to be inflexible. I suggest you use a guide tube before the driver motor. This will make sure that the bend radius is better managed. Also avoid long straight lengths because all the while it is being held straight, the filament is developing micro-cracks.

In the bowden tube... definitely a pointer to the filament starting to show its age. If doesn't keep it from printing, but feed failure is always a risk.

And absolutely, the temperature has a lot to do with it. Put a box around the printer and spool and blow a small heater through it or something. Don't let the filament get saturated with cold either.

I use to rewind 3rd party filaments on my cartridge spools (different printer). And when I did that, some filament would snap over the next hour or so and I would wind up with 100's of pieces of filament. Of course you know what the manufacturer said...




"well, don't do that then!"



True that!

[Nick]

I found the issue. So on both printers the hot end fans were not blowing due to a blockage. One little peace of old filament on one and dust bonded together on the other. The issue was overheating and that melted the filament in the Bowden tube and up to the extruded where the filament would melt apart. The filament would be so hot that I couldn’t pull it out of the Bowden tube as it melted in peace’s throughout the tubing. The fans are working now and the printers are printing. So far so good.

[TommyDee]

Now that makes sense Thanks for sharing the solution!