Clog in the extruder

Basic Information:

Printer Model: Ender 3 personalized
MCU / Printerboard: Octopus 1.1v
klippy.log

Hi everyone, after some printing time, clogs are created in the extruder
mold at 180 degrees for the extruder and 60 degrees for the plate
in addition, molten plastic comes onto the extruder

klippy.log (2.1 MB)

A clogged extruder is rarely an issue of Klipper.

Either wrong filament settings, bad filament or both.

Actually, 180°C is quite low, even for PLA.

What kind of filament are you printing with?

You may heat up to 220°C and manually press filament through the extruder. This may clean it,

I use BIGTREETECH’s filament
anyway, I tried to use 200 and 210 degrees, but it was the same thing, if not even worse

What hotend do you use?
Bowden setup or direct feeder?

In most cases the root cause is a gap in the nozzle/heatbreak/bowden system where the filament cools down and becomes solid and finally clogging the hotend.
Sometimes that leakage flows out of the hotend/heater block messing it up…

I tightened it to the max but it’s the same thing

I have nothing to add other than “Clog in the Extruder” would be a good band name

3 Likes

This was a mistake I made when I got my first printer. The nozzle threads into the bottom of the heater block and the heatbreak threads into the top of the heater block. What you want is for the nozzle to be tight against the heatbreak, not against the heater block. I had a huge problem with clogs/jams and filament leaking out of the nozzle threads and dripping onto the print. I tried to solve it by cranking the nozzle down tighter, which eventually caused the aluminum threads to strip out of the heater block. The problem was that even with the nozzle as tight as it could be against the heater block, there was still a gap between the nozzle and the heatbreak inside the heater block, and liquid filament was seeping out there causing blobs and oozing, and then afterwards it would harden there causing jams.

I would suggest disassembling your extruder and clearing all the filament out of the nozzle, heatbreak, and heater block, then when reassembling it. put the nozzle in the heater block first until it’s finger tight against the heater block. Then thread the heatbreak in the other side until it stops. At that point it should be tight against the nozzle. Test this by unscrewing the nozzle about a full turn and verify that you can now thread the heatbreak in another full turn. If so, your heatbreak is in a good spot. Finish reassembling your extruder. Now when you tighten the nozzle, you’re tightening it against the heatbreak rather than the heater block, and that should solve your problem.

NOTE: This assumes you have an all-metal hotend. I just remembered that my original Ender 3 had the stock hotend where it was the bowden tube that met the bottom of the nozzle. If that’s the case with your hardware, the same principle applies–you need to eliminate the gap between the nozzle and the bowden tube. One way to do this is to unscrew the nozzle about three quarters of a turn, then shove the bowden tube in until it stops at the nozzle, then tighten the nozzle at least a half turn to snug it down. You may have to replace your bowden fitting if the tube has any play, or if it allows the tubing to slip. And you may have to replace the bowden tubing if it’s gotten shaved down by the teeth on the fitting. There are also shims you can print to shove under the collar of the fitting to help make sure the teeth stay engaged and reduce slipping.

2 Likes

We still don’t know much more about the used hotend/hardware…
The thread starter saves on pieces of information but wants a definite solution out of that what is not related to Klipper…