Hi all. I got my X1C with AMS end of January and am very happy with it!
Not only but also being able to print flexible parts from TPU has a huge potential for me. Unfortunately I have been struggling every time I tried to unload the TPU, which I print from an external spool:
It seems that heating of the nozzle as well as cutting the filament works just fine. After I have retracted the filament manually the feed starts running and won’t stop again (I assume its the AMS-feed and not the one in the extruder itself). The printer most likely tries unload the filament through the AMS but quite obviously can’t as it has already been removed manually. But as the printer still seems to be recognising the filament in the extruder, an error is caused. The only solution I found is to completely disassemble the extruder in order to manually get the cut off part of the TPU filament (as shown in the pictureattached) out and re-assemble everything.
Anyone already has a solution therefore? I already tried to look up in the forum but couldn’t find this exact same problem. If there already are solutions to this, which I didn’t find, I am happy to get them linked as well.
I am having this exact same issue on my P1S. Did you ever figure this out?
I’m on my 3rd or so attempt using TPU (which prints great). but when i’m done and have to remove the external spool, i feel like i’m following the instructions on the screen to a T (starting with clicking the “unload” button, and then when it tells me to, to retract onto the spool, etc). I end up with this small piece of filament in the sensor area which the only way i’ve been able to fix is to completely disassemble the extruder to get out. This small piece is causing it to think there is a jam; the only thing i can suspect is that it has to do with the fact that it is TPU and quite flexible, so its messing up the process of a standard external spool removal.
Speaking of which, i fairly regularly print from the external spool (even though I also have the AMS) and it’s only happening with TPU.
Actually I didn’t print TPU for quite some time but then hat to make some parts just last week!
Long story short: I still have the same issues! But from time to time I get to unload the TPU from an external spool without issues (maybe once out of 5 times). I have a friend, who also owns an X1C and is regularly printing and unloading TPU from the external spool without any issues. So in general this seems to work (at least using 90 or 95A material from Polymaker).
So what my suspicion is so far: IT seems that the cutoff TPU bit is somehow pushed back by the extruder feed, which causes it to cover the filament sensor in the extruder which is then signaling to the printer that there is still some filament in there. Interestingly at this stage the feed of the AMS enganges and also won’t stop again. So it seems that the AMS is trying to unload the filament from the extruder even if the printer should know that the last material was printed from the external spool?!?!
What I found out: Instead of disassembling the whole extruder you can just remove the PTFE tube from the printing head, unbolt the extruder from the printing head, remove it (even leaving the cables on) and then grab the filament piece from the top through the tube connector with a pair of pointed tweezers. This at least does safe some effort. Eventually you could even process this operation with the extruder installed in the printer head. But then you would need access from the top of the printer, which would require to disconnect the AMS and remove the glass top - probably a comparable pain to what I did…
What I intend to do next: Basically I would like to get back to the Bambu support. But currently I am not yet running the latest FW (1.08.00 instead of 1.08.02) as I frequently read about issues with the latest version (no idea if this is still the case). So I assume the first thing the support would ask for is to upgrade FW anyway…
So in a first step I will try to optimize the workflow of getting the stuck piece out there. But sooner or later I will get to Bambu. Somewhere they should be able to see what exactly causes the extruder to push back the filament (I even sent them pics comparing some cutoff ASA printed from the AMS vs. the cutoff TPU from the external spool - there is a clearly visible difference.
Even if this isn’t a solution yet - I hope the helps!
I print 95A TPU from time to time and have never had this problem.
When unloading the nozzle heats and the head moves front and left to actuate the filament cutter. The head then returns to the poop chute and feeds a little filament to push the cut off bit a little way into the heat break. Then it retracts the filament and tells you to pull it out.
Your problem looks like when pushing into the heat break the two ends get stuck together and cut off bit gets pulled into the extruder where it breaks off.
It has never happened to me so I can only guess it is something to do with the filament and how sticky the cut ends are at some temperature and what temperature it is at.
Possibly a bad cutter blade is the cause.
I imagine pushing the cut part into the heat break a bit is just to make a hole for the next filament to go down reducing the possibility of it being deflected sideways. I also imagine this is all controlled by g-code in the printer or filament profile so you may be able to remove the pushing into the heat break bit to solve the problem.
I had this issue breifly, it was resolved when i dried my filament. Great first print (probably because it was simple and i couldnt see any of the stringing since it would have been inside the model) then problems problems problems, dried the filament and it went away.
