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Filament breaks just after extruder tensioner  

New Member
Filament breaks just after extruder tensioner

Hello, I have a relatively new MK3S+ purchased assembled. Just recently had my first extruder problem, where the filament broke just after the metal gears. I was able to remove it carefully with pliers, and did a cold pull procedure and proceeded with a new print. All was going well onto the print until I was about 5 hours into it (it was a 5h24m job) when the same thing happened. What is next for me in terms of diagnosing this?

Thanks in advance.

Posted : 22/10/2021 3:08 am
Dan Rogers
Noble Member
What is breaking your filament

Is there a knotted spool situation causing your prints to jam up?  It takes a lot of "not feeding" for the gears to break the filamement.  Is your spool spinning?  Is the filament knotted on the spool (unwind about 30 feet carefully looking for a traveling knot).

If the spool feed is removed as a possible cause - another cause is bad filament (brittle).  This can be due to age, heat, moisture ... some rolls get so brittle they just need to be thrown out.  But brittle filament is rare for a noob, so I'm thinking you got a knot.

Posted : 22/10/2021 9:03 am
Noble Member

Like Dan, I have a hard time seeing any scenario in which the extruder could break the filament in that spot by itself. Brittle filament would have been my first guess because a knot would be pretty self-evident. And I assume your nozzle temperature is hot enough for the filament you're printing?

Posted : 22/10/2021 10:45 am