Notifications
Clear all

Filament stuck above gears  

  RSS
Pobi
 Pobi
(@pobi)
Active Member
Filament stuck above gears

Hi all,

I was doing a filament unload on my MK3S+ and it got stuck above the gears. See picture. I cut the filament so that I could put the spool away. I've tried pulling on the filament and pushing on it but it won't move. Is there anything else I can try? I'm trying to avoid having to completely disassemble the extruder 😓 

Thanks for the help!

 

Posted : 25/03/2021 5:20 pm
Dan Rogers
(@dan-rogers)
Noble Member
RE: Filament stuck above gears

That set of gears - one is fixed position and the other is on a spring loaded arm.  The arm part comes off the extruder without a lot of disassembly -  back out the tension screw and wiggle on the end of your filament that is still not cut too short to work with ....

Posted : 25/03/2021 7:07 pm
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

The filament snapped during wiggling 😢 I can't pull on it any more. Pushing doesn't seem to have any effect.

This post was modified 7 months ago 2 times by Pobi
Posted : 25/03/2021 7:59 pm
fuchsr
(@fuchsr)
Noble Member
RE: Filament stuck above gears

To me the extruder path doesn’t look okay in this picture. Isn’t the filament way too far to the left from the idler? But maybe it’s just where the idler is positioned after you swung it open. 

So the filament is not extending through the gears into the heatsink? Then I’m not sure why it wouldn’t come out when you pull on it. Or try to take needle nose pliers and pull it out downward through the idler window.  

Posted : 25/03/2021 9:20 pm
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

@fuchsr

I think it's just the angle of the picture. Unfortunately the filament is now broken such that there are no parts sticking out of the "shaft" so I don't have anything to grab onto. It doesn't budge when pushing it down from the top.

I'm wondering if I didn't pull it quickly enough during unload and it got stuck to the inside of the shaft.

Going to wait a couple days in case anyone has any ideas before I bite the bullet and take apart the extruder.

Posted : 25/03/2021 9:40 pm
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

I just stumbled on https://help.prusa3d.com/en/guide/2a-mk3s-extruder-disassembly_188397 which is super helpful! The filament is stuck in the "Adapter-printer" so I just need to make it to step 7. This is looking much easier than taking the whole thing apart. I'll update this thread when I have time to do it.

Posted : 25/03/2021 9:52 pm
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

Update: I can't remove the Adapter-printer because, since the filament is inside, the steel ball is pushed out and blocks the piece being removed. I should have seen that coming

 

The filament is clearly visible now that there's a gap in the extruder parts:

 

Note that it seems like the filament isn't aligned with the gear because the extruder parts are apart at an angle (see https://help.prusa3d.com/en/guide/2a-mk3s-extruder-disassembly_188397#188457 for details).

Even though the steel ball is blocking the removal of the Adapter-printer, I'm still able to raise it a little bit. With the adapter raised, I'm able to push the filament down more. When the adapter is pushed back into place, the filament is pushed back up into the adapter. This leads me to believe that the gear itself is preventing me from pushing down the filament. Unfortunately I'm not able to grab the filament from the bottom using the needle nose pliers.

I will continue updating so that others can benefit from my trials and in case anyone has tips/ideas.

Posted : 25/03/2021 11:13 pm
esev liked
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

I bit the bullet and took apart the extruder. The piece of filament that got stuck looks like:

It had gotten stuck in the gears like this (the part and filament are in the correct orientation - to picture how the filament was stuck, translate it to the left into the adapter-printer):

 

My best guess is that the filament had a little glob at the end that was slightly wider than the adapter printer hole and when the gear moved the filament up, it didn't go in the hole and instead got stuck and smeared by the gear.

Disassembling the extruder wasn't that bad and it was fun to get re-acquainted with all the parts. If anybody has any tips on how to prevent this happening again, please share! 🙂

Posted : 06/04/2021 2:12 am
esev
 esev
(@esev)
New Member
RE: Filament stuck above gears

Thanks for documenting all this. I had a similar issue today. This post really saved me some time.

This leads me to believe that the gear itself is preventing me from pushing down the filament. 

That was the key for me. After opening the idler door, I was able to go into Settings > Move axis > Extruder and cause the gears to move. That, in combination with pushing the filament from above, was all it took to free the filament. I was then able to cut the glob at the end and pull the filament out.

Posted : 15/06/2021 12:49 am
Pobi
 Pobi
(@pobi)
Active Member
Topic starter answered:
RE: Filament stuck above gears

I'm happy that you found it useful 🙂 This reminds me to add some updates that might be beneficial to others:

I had tried the same process mentioned by @esev but the glob was such that the gears couldn't push it out, even with pushing the filament from above. I recommend you first try @esev's approach but if it didn't work for you, keep reading.

This issue happened a second time soon after after my last update and I discovered by chance another way which ended up working and avoided another full disassembly. The following might work for you:

  1. Cut off the top of the filament that's sticking out of the extruder, but leave enough to hold on to (3cm maybe).
  2. Open the idler door completely.
  3. Twist the top of the filament from step1: Roll it between your fingers. If you're lucky like I was, the stuck "L shaped glob" (see earlier pictures) will rotate outwards 180 degrees toward the open idler door. If it doesn't rotate out, you might want to try loosening the extruder (steps 5, 6, 7 from https://help.prusa3d.com/en/guide/2a-mk3s-extruder-disassembly_188397 ) and trying again. 
  4. You can then cut off the glob and pull the filament out.

 

How to prevent this from happening again? I loosened up my tensioner quite a bit. The head of the idler screw now protrudes from the body. I have done a few hundred hours of prints and the issue hasn't happened again. You may want to consider playing with the tensioner if this issue keeps happening to you.

Good luck!

Posted : 15/06/2021 3:48 pm
esev liked
Share: