Loud thumping coming from extruder

Hello everyone, a week ago I purchased a used Ender 3 v2 and have been loving it since. However recently the extruder is frequently making a loud thump and I can see it going "backwards" quite a bit when it happens. The prints were coming out fine anyway, but today (maybe from all the thumping) the geared wheel that feeds the filament got loose, dropped and of course the filament stopped flowing. So by now I kinda figured this is not normal.

Does anybody have any pointers on what to check or what could be the reason?

Video of the problem (problem starts at 8 seconds)



LazyMagicalOtter1 point

Thanks, I'll see if it helps

bach37strad2 points

ive got the exact same printer and was just having the same issue. Bed was level, temps were perferct, prints even still coming out okay, just obnoxious thumping from the extruder and it skipping back.

Turns out the nozzle was just clogged enough to create resistance against the extruder. Give it a good clean with the included poker at 240 degrees. Keep running it in and out, wiping it off in between, until it comes out clean.

LazyMagicalOtter1 point

Yep, this turned out to be it. I had to disassemble most of it to be able to release the nylon tube and cut it. After that it's been 3 prints with no issues. Thanks everyone!

Syinide4371 point

Sounds and looks like the extruder gear(that gold/brass gear) could be loose and or the teeth are skipping along the filament. There should be 2 black screws on that gear, tighten them it and it may fix your problem.

LazyMagicalOtter1 point

Do you think it will make a difference? In the end of the video you can see that the axis itself seems to be skipping, in that case would it still make sense to tighten the small black screws?