Error- filament tangled or spool stuck, but spool is OK

Bambu Lab A Series Troubleshooting
1

Greetings, colleagues!

I’ve looked through the topic and used the search, but couldn’t find anything similar.

Bamboo Lab A1 (not AMS) printer, which I’ve been using for a year. It has printed approximately 15 kg of PLA, and everything was fine. Yesterday, after changing the spool, the new filament was loaded normally, and the extrusion process for cleaning the old and filling with new filament was completed.

I started printing, and during the preliminary calibration stage, the printer started showing an error saying that the filament was tangled in the spool or stuck in the tube. The print head automatically moved to the right, cut the filament, and moved to the left above the waste container. The print was paused, and the head stay heated.

I checked the spool—everything was fine, it rotated smoothly, and I found no obstacles. I pressed on the display that the problem was resolved and printing could continue. The printer re-loaded the filament, extruded a blob as during flow calibration (and I monitored it—the flow was smooth and quite voluminous, the filament fed from the spool without issues), smoothly moved the head to the right, and again cut the filament and displayed the same error.

I changed the filament spool to another one that I had already printed with, but the same result. I rebooted the printer—initialization passed without errors, but when starting a print, as soon as the preparation process begins, the head moves to the very back of the table, where it makes the first calibration touches, after which it should clean the nozzle on the plate—it immediately returns back, cuts the filament, and displays an error.

I removed the PTFE tube and plastic filament guide, fed the filament directly into the extruder—no changes. During filament testing during loading, the filament pulls well with noticeable force, no need to push it. The loading process completes without errors. But when starting a print—that’s it, an error—the filament is tangled on the spool, and filament feeding is stopped.

I disassembled the extruder—everything visually clean, but just in case, I thoroughly wiped the notches on the wheel, assembled it, started it— no result, same error.

I changed the nozzle to a new original one— no result, same error.

I haven’t run calibration yet; I don’t think it’s about the bed leveling…

What else could it be? Is the extruder motor acting up? I can take a photo of the error code, but perhaps it’s a known issue, and the experts will immediately guess?

2 Likes
2

It is possible you have something stuck in the head somewhere.

Try this guide and follow the steps. If the blockage is there, it will help you clear it out.

You may have a small piece of filament broken off in the mechanism, it doesn’t often occur, usually due to brittle filament or sometimes, just because.

Good luck.

3

Thank you Malc!
Head extruder was completly disassembled and checked. Nothing was inside. And filament comes in and out fine. I’'ll check later with switch off tangle sensor

4

Double check the ptfe tubing. Unhook it from the toolheads pneumatic coupling and make sure the metal teethies haven’t “bitten completely through it”. If those metal hooks end up in the plastic it can read like a snag

5

So I had this happen, though with AMS Lite. Checked everything, all clean. Filament was clearly making it to the nozzle, but got that message nonetheless. Sounds like you might have the same issue.

Turned out it was the sensor on the extruder. It stopped working after I had a brain fart while trying to manually pull back the filament, so pretty sure that broke it since it is pretty sensitive.

It was a cheap and fairly easy fix. Had to order a new sensor ($5) and watch a YouTube video on the process. But overall only took about 30ish minutes. Hardest part is that it requires you to go into the back of the extruder unit where the board is and unscrew a few tiny screws (not easy) and pull out a couple cable heads.

Note: I got a different error after that the extrusion pressure sensor wasn’t working. Turned out I had flipped the eddy coil screws on the back. So with the two screws that hold the black wires in, good idea to mark them somehow so you know which goes where.

2 Likes
6

Ok, I have been printing for six months. A1 and AMS lite. In that time I have had some issues, needless to say, I have exchanged my printer three times for some odd ■■■■. NOW I have been having this same error. I took apart the print head, checked the gears, cleaned it all blah blah, still had the problem. Ordered new PTFE, got them, inserted them, same problem same error.
Went to microcenter, got a replacement, built it, same error with first print. (a vampire I got off a subscription which worked before). Decided tonight the problem must be the AMS. Got an ams replacement (thank god for Microcenter and their exchange policy). Hooked it up same error…

So I have all new equipment, same error. In the last three days, new A1 new AMS and not one successful print. Gave up on the vampire, tried a benchy same error. Read to turn off Filament sensor, same error. Checked hot end. small piece of filament in there, took it out same problem.
It was loading filament fine when I put everything together, just giving me the extrusion error tangled or stuck wheel.

Can someone help me. I am not a tech person. I love this printing, its been really fun, spent loads on really good filament brands (stuff I see everyone use) I will never print the vampire again, I promise, so long as this works. I don’t know what to do, and no one locally fixes these things. There is no expert, I can say, come look at this…I have no more patience. I just have a lump of metal and plastic now that wont do anything…im beside myself.

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And it loads filament ok when i load from the ams. The print just goes wrong

8

Have you tried feeding the filament directly to the printer without an AMS?

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It loads fine when I go to the a1 screen and say load filament.

10

It also just printed a benchy from the top of the machine (without the ams)…
Just tried to print a benchy from the ams, and told me that there was filament in the extruder, but not when I printed from without the ams. I have also noticed that when I take the hot end out, there is a piece of filament in there each time. like a stub I have to pull out. This has to be a software problem right? three different machines?

11

It has to be something in common with the machines. Software is the most likely issue. Bambu seems to run fast and loose with software/firmware releases. Have you “enrolled” to be a beta tester for software/firmware?

12

Your descriptions aren’t enough to really give more advice on.

Error codes, screenshots of errors, pic of the result of a print, picture of the ams as assembled. Anything. This is a forum of unpaid users you’re gonna need to help us help you

13

I’m having this same issue. Started a few days ago, about a week after I got my printer. I’ve tried cleaning the nozzle and the ptfe hub. I’ve tried different brands and different ams lite spool holders (happens on all 4). The one spool with bambu pta filament will sometimes print, but the print is very stringy, there are obvious quality issues, and it stops mid layer to reheat the nozzle, purge, and load new filament (single color prints, btw), wasting a TON of filament and making a huge mess. I’ve even tried a brand new spool fresh out of the vacuum sealed bag. The filament is in a dry box I built where the humidity stays around 35% or lower, and I even bought a filament dryer and tried using filament dried for 4, 12, and 24 hours. Still no go. I literally watch the filament travel through the ptfe tube to the extruder, watch it purge the old and load new filament all with no issue, then get this error. I’ve tried every fix and suggestion I’ve found online with the exception of turning off the tangle sensor, though from what I’m reading above, I doubt that is going to help, and it seems like something I would actually want on. I guess replacing the sensor Flurpus mentioned (anyone know the actual name, so I can go about ordering one of them?). At my wit’s end with this. $1000+ spent, and nothing really to show for it is pretty disheartening.

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PLA filament, not PTA - sorry, it’s early. And I didn’t see a way to edit the post lol

15

Well, I just disabled tangle detection (Settings > Print Options > Tangle Detection) and everything seems to be working fine now. I suspect the filament sensor in the tool head is the issue, as I believe that is where tangle detection comes from, but if anyone knows different, please let me know.

1 Like
16

that did the trick for me as well. If you find a different solution I would be really interested

17

Seems I still have the same issues with multi color prints using the ams lite, but at just the printer is usable again. So… Not sure where to go from here.

19 
I had the same problem and the solution was to disable the filament tangling detector. Has anyone found another solution?