Filament curls and sticks to extruder

I am having an issue where filament is not coming out of the extruder correctly. It curls around, and the filament that is being extruded is getting stuck on the extruder. It ends up curling around.

I have attached a few images of what is happening.

What do you think the cause is? What should I do to fix this?



This happens to me all the time when I’m changing filament. It has never caused a problem with the actual prints though.

I’ve noticed it happens more for me when the hotend is dirty. The one in the picture looks pretty bad.

Do you have any recommendations for how to approach cleaning the nozzle? I feel like it always seems dirty no matter what I do.

You’ll want to use a scotch brite pad or something similar to clean the nozzle, just make sure NOT to use a metal brush.

I like to use 3M Scotch-Brite 07448 Ultra Fine pads to clean nozzles when I do. They are also great for cleaning fencing foils. That being said I rarely bother cleaning the nozzle.

You are using tweezers to remove drooled filament as the print is homing/starting, right? I have never had to clean nozzle with scrubber pad, although I think it is a good idea.

Pete

Cleaning the nozzle wouldn’t hurt, but this really shouldn’t be a problem during a print. If the auto-leveling is working correctly, the nozzle should be close enough to squash the extrusion into the bed for first layer), which keeps filament adhered… and away from sticking to the nozzle. Might be time to flip or replace your cleaning pad.

I add a 2-3 perimeter skirt to prime the nozzle at the beginning of prints. The skirt also removes any unwanted filament from a “leaky” nozzle… because I like to extrude at a higher temp initially to promote filament adhesion to the bed. Increasing the bed temp by a few degrees can also help with adhesion.

If you think the nozzle is too far from the bed and reducing adhesion, try adding a Z-offset in your slicer. Negative .05 or .1 should help with the squash increasing adhesion. Long term, there may be a gcode command to adjust the nozzle height in firmware.

If you haven’t cleaned the PEI bed, probably worthwhile to do so also. A bit of alcohol or acetone… and/or high grit sandpaper. A Mr. Clean Magic Eraser works well on its own also.


Hope this helps.