Ender 3 MAX Unusual Extrusion Issue

So I’ve been scratching my head over this one ever since I tried to upgrade my mainboard with a BigTree Tech SKR Mini v3. That board has a bad USB port, but it’s a different issue.

Ever since attempting that install, my extrusion has gone wonky, blocking hot ends and nozzles constantly. So, my first thought was to upgrade to the Revo CR HotEnd, which has at least relieved the constant blockages for the time being but my extrusion issues remain.

I have:

  • Changed bowden tubing numerous times with same results

  • Replaced extruder assembly and gears, brass drive gears

  • Calibrated E-Steps and PID Tuning

  • Levelled bed a stupid amount of times

    What I’m finding after all this, is the problem is related to the drive gear arm. Where the brass drive gear fits, on one occasion it has ridden up the drive arm, and was really difficult to take off. When I took it off, I had to file down the drive arm to fit another brass drive gear again. Once that was done, I noted the exact instance of the issue:

  • The drive gear companion (the one that just spins beside it) during an E-Step tune wasn’t moving, and my nozzle stopped extruding. So, I remove the filament and took a look. There is definitely warping of the filament, almost like it’s under way too much tension, however my extruder isn’t that tight and I know how to tighten it properly.

    So, I’m stuck at this point thinking I need to replace my drive gear arm/stepper motor, maybe it’s warped? There’s an odd issue going on here, why does my extruder work ‘sometines perfectly well’ with the right filament extrusion, then suddenly it could under extrude with very thin filament lines, or stop altogether? Certainly the filament is warping or getting pressed too hard. Does anybody have experience with this issue? Picture is where the filament was jamming at the hotend, even though the rest of the filament wasn’t messed up to this extent.

Hi @Slypty01

It sounds like your extruder is tensioned too high causing it to chew through the filament. I would recommend removing the silver screw that holds the pulley on and checking that no debris has got into the pulley causing it to jam. I would also recommend adjusting the screw that I have circled in the following photo, this screw controls the amount of tension applied to the filament, you may find by loosening the grip on the filament slightly you wont get the chewing up of the filament on the gears.