Filament Break in the Path: Enhancing User Experience

I’m puzzled by the recommended solution for removing broken filament from the AMS ( Wiki - Filament break in the path ).

Wouldn’t a simpler method be to disconnect the PTFE tube from the back and allow the AMS to push the filament through until it falls out of the end of the tube?
Using another spool of filament could ensure the stuck filament is effectively pushed out without getting jammed again.

The suggestion to disassemble the machine seems overly complicated for a piece of filament that could be more easily pushed through rather than pulled out. This method could save users a lot of time and hassle. However, to my knowledge, this solution isn’t currently an option, which seems like an oversight. I believe Bambu Lab should investigate and possibly implement this as a viable solution.

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There are more roads that lead to Rome. I would go for the most straightforward solution instead of demolishing half the machine.

There is a motor that helps to push the filament to the printers toolhead. Its at the AMSs internal hub. You cant jog the motor, the only solution is to tear down the AMS. To get to the broken filament.

Sucks! But most of us have done it multiple times.


Not so. A nice piece of 1.5mm diameter piano wire can be used to push busted pieces through from above. You can use filament instead, but it’s a pain to hold down the pushbutton thing while you do it. The smaller diameter piano wire feeds without much friction from those things.

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I forgot to reply to your post! :crazy_face:

That is a good idea to use piano wire. And I do have some that is 300mm long. I will try that if I remember to use the piano wire.

It does not happen to me very often.


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I use the stuff for my model airplane hobby, so I had some handy when my first broken filament AMS “jam” happened. I considered just pushing filament through manually, but didn’t like the friction I had to fight. A smaller diameter piece of flexible something seemed like the right idea so I went looking through my inventory to see what I might have. I had some Carbon Fiber too, but I was afraid it might snap in a too-sharp corner and make things worse. Pushed right out with the piano wire, though.

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Ok, folks, I think I’ve come up with a less invasive solution and hope it inspires BambuLab to create a process that would solve the problem. You’ll only need a piece of filament about less than 50cm long (enough to go in and out of the end of the AMS). Use PETG or ABS, as they are less likely to break.

Step 1:
Turn off the printer and disconnect the AMS and its PTFE tube.


Step 2:
Remove the plastic piece that presses the PTFE connector inside the AMS, giving you access to the filament-pulling motor. To remove it, simply pull rather than push. If you have larger fingers like mine, you might find it easier to use a screwdriver as a lever. But the piece comes off quite easily; I’ve actually removed it before by accident.

Step 3:
Insert the piece of filament into the slot where you have the filament stuck until you feel resistance from the other filament stuck inside. Put your finger on the right side in the gap opened by removing the plastic piece. You will feel the gear of the motor that pulls the filament, which only rotates in one direction, fortunately in the most comfortable direction to turn with one finger. Pushing the filament and rotating it, you will feel the filament start to move. Repeat until the tip of the filament comes out enough for you to pull it out by hand.

Step 4:
Gently pull the stuck filament out, I say gently because you are turning a motor, and it may generate electricity and potentially damage something (I think :sweat_smile:). Repeat Step 3 to ensure no pieces are left. There, you’ve removed the filament without needing to dismantle everything!! :grinning:

For future iterations, I’ve left the plastic piece off and inserted a 60mm piece, enough to use an external connector. I used the printer’s own connector since I had replaced it with a Y-splitter before.

In the future, I believe the process could be simplified to just removing the PTFE from behind the printer and having the AMS push the filament, using another or the same spool. By pushing about 50cm at a time, you could repeat the process until every piece of the stuck filament is cleared. I’m really happy with this approach and have used it more than once. I hope BambuLab sees this and shares their thoughts too. Happy Printing!!!