My filament is bunching up in the PTFE tube and jamming.

[Gaurav_Nandkeolyar]

My filament is bunching up in the PTFE tube and jamming. See attached pictures. It looks like the extruder is trying to force more filament into the nozzle than it can melt.
I have tried the following:
-changed filament rolls
-replaced nozzle
-replaced hotend
-replaced PTFE tube
-tightened everything
-checked extruder for clogs by opening it up and then greasing the wheels.

Some help would be appreciated. next step I am replacing the extruder motor.

[Kevin_Eames]

Hi

Looks like you really fired the parts cannon on this one.

I would suggest this “could” be heat creep, the filament is softening after the extruder gears but before it gets to the hotend.

There is a heatbreak built in but it is VERY dependent on the hotend fan.

There is also heatpaste applied to ensure heat is transmitted to the heatsink efficiently, have you replaced this?

Creality is known for poor quality fans so have you checked this is working correctly?

There are mods to be able to use bigger fans from the like of Noctua.

Have you checked the the Estep calibration, if this is correct then unlikely to be the extrusion motor.

[Gaurav_Nandkeolyar]

Thanks for the reply.

1. This is my new (third) unicorn hotend and I replaced the whole thing (the stock one got death blobbed) and the replacement (also the unicorn) was working for a few months before this issue. Where would I apply the thermal paste? I looked at the manual and the instructions that came with the hotend and there is no mention of applying paste.
2. I have ordered a replacement hotend fan as well. It is a bit noisy so might be failing. I had to replace the motherboard fan a few months ago because it was failing.
3. I have not checked the Estep calibration. My extruder motor is no longer turning so it might have failed. I’ll take out a multi meter tomorrow and check if its getting voltage.

[h3li0]

try reducing the volumetric speed on the filament settings on the slicer, it seems like you might be running it too fast

[Kevin_Eames]

[Gaurav_Nandkeolyar]

Thought I’d update this thread so it might help other people in the future.

1. I checked the thermal grease between the nozzle and hot-end. It was there from the factory and not the problem.
2. It was the extruder motor that was failing. Installing a new one fixed it.
3. I also replaced the hot-end fan and it’s a lot quieter now.

I am very surprised that I have had to replace so many parts on a printer less than 6 months old.