Filament broken off between hotend and extruder. This has happened twice now and each time means disassembly of the print head and a destroyed print. Each time it is a small piece of filament about 5mm in size which is stuck after the extruder and before the hotend and must be removed manually.
It happened with Generic PLA filament and also with the original Bambu Lab PLA filament.
The broken parts are always smooth and not melted or anything. It almost looks like a smooth cut.
Filament brand, I had the same problem several times with all Geeetech filament from lowcost to premium PLA, now with the Bambulab printer I only use ESun brand and Bambulab brand (I began some tests with Sunlu, it seems to work great too)
EDIT: I forgot a bit of explanation, Geeetech filament become very brittle when they are left in the AMS for some hours (not all the spool, the part that have been charged between the AMS feeder and the hotend), probably true for some other filament brand.
EDIT2: Sorry just see you used Bambulab filament, I did not have any problem but it may depend on type of filament, do they are brittle when you try to break it with hand (the filament that have already be out: the part that have been charged between the AMS feeder and the hotend and rewinded) ?
As a rule of thumb regardless of the manufacturer before I feed anything into my AMS I’ll unspool about 12" and bend the filament
If it snaps into the drier it goes until it’s pliable and doesn’t snap
The only time I run somewhat brittle filament is glow in the dark because although it’s pliable out of the drier it absorbs moisture so quickly that by the end of an 8 or 10 hour print it’s brittle again
The filament is not brittle. The one came with the Printer, the other is a brandnew pack of Extruder PLA. Both are flexible as new PLA can be.
The prints where this happened were both multicolor prints with 4 colors. Both breaks happened in the first half of printing a 2h job.
The printer was delivered last week. Since this I already got prints of hours with apx. 1.5kg filament ran through. No problems anyway but this stuck filament parts in the middle of the printhead f*** me off.
I’m not 100 per cent sure about the first print. At any rate, I assume it was.
But on the second one, it was definitely during the colour change. I’ve observed that live, so to speak.
Dunno, if both ends are smooth probably it’s not filament breaking at all. Maybe during loading new filament it got stuck (or erratic detection of such), then printer cut off a small piece which already loaded to unwind the rest. Or some error in G-code which caused filament cut and unwinding without purging/printing it first.
Did you ever solve his? Im having the exact same issue, about two hours in filament gets broke in the hotened. Replaced the hotend, replaced the extruder, dried the filament, new filament, doesnt matter same result, and it just started happening out of nowhere.
No, I have not yet been able to solve this conclusively. However, I have not yet been able to find a definite cause. In my case, it appears out of nowhere. It is also not linked to a specific filament. Except for TPU, it actually occurs everywhere. I suspect that the drive of the AMS, which is set quite tightly, is responsible for it. (I do not print TPU via the AMS). In any case, I have not had this problem so far when I have printed without the AMS.
It is then a tiny crumb of filament that seems to lie in front of the sensor. So far I have been able to solve this somehow during operation. In the simplest case, manual operation of the filament cutter was sometimes enough. In the worst case, I had to remove the hotend and the extruder.
Of course, this is particularly unpleasant during operation, especially when working with high print bed temperatures.
Thanks for the reply. Sorry you haven’t found a conclusive resolution. I’ve swapped extruder, hotends, ams units (one brand new) new filaments previously used filaments and still nothing. I even used without the AMS and still the same result. Very perplexing, I have a ticket in with Bambu support so hopefully they can offer some help. Disappointing to have the printer dead in the water. I’ll be sure to post if I get or find a fix. Good luck to you!
I suggest loading/unloading any problematic filament manually without AMS up to several dozens of times to see if it happens during filament unload. And especially watching filament cutter lever, if nothing dodgy happens with its operation. Apparently printer detects its position The printer shows that the cutter is stuck | Bambu Lab Wiki so I wouldn’t be surprised if hall sensor fails to detect it’s position when filament is cut on a first try (so it thinks it wasn’t able to cut filament), or it actually cuts only partially due to dull blade, and then re-attempts cutting which results in that small piece.
I Got same problem, brand new printer if i print with more than one color i snaps when it tries to change color in extruder, and with only one print it snaps when the print is 99% done. I have not made one print on it without that problem, i want my Prusa back
This is with 4 diffrent types of filament inclusive 3 brand new Bambu lap pla.
Has anyone seen any solution to this issue? I’m still experiencing this with every single multi-color print. replaced every part I can think of, used all new filament from Bambu straight out of the package, still multiple failures every print. At this point the wires from the extruder assembly are starting to become frayed due to the number of times I’ve had to remove it to get out the piece that remains cut off inside. The printer is less than a month old and I’m already up to replacing the entire extruder assembly?
Don’t trust the filament samples from Bambu. My green PLA was very very good, but the PLA CF needed a lot of refreshing. Broke many times. After 12 hour drying it was a lot better. I’ve tried several brands and got the same result. It’s like poker
Just cause it is new doesn’t mean it isn’t brittle. Where it is manufactured could be quite humid and most likely is. Most filament is made in China where it is quite humid. Most of my filament comes in and when I put it in the dryer registers around 40% humidity. After I dry it, it is at 19%-20%
Habe bei meinem erst 2 Wochen alten P1S das selbe Problem. Da auch noch ein AMS verbaut ist, wird das auch in Mitleidenschaft gezogen, da auch ein Filamentantrieb verbaut ist, kommt es am Hotend, am Xtruder Kopf und am AMS Extruder zu Verstopfungen. Das Filament lässt sich nicht zurückziehen oder ins Hotend einführen, so dass die Extruder Antriebesräder das Filament zerlegen.
Den Grund habe ich eigentlich schon gefunden - der Platz zwischen Hotend und Extruder, wo der Filamentcutter arbeitet. Wird zuviel Filament nachgedrĂĽckt, kann es sich dazwischen verbreiten und abkĂĽhlen, was zu diesem Propf fĂĽhrt. Das ist aus meiner Sicht eine Fehlentwicklung.
Geschuldet ist es eventuell auch der Geschwindigkeit, die Bambu Lab für Generic Filamente vorgibt. Das “Extruder ASA” z.B. soll nach Hersteller mit 225 bis 240 Grad Celsius und 40mm/s gedruckt werden. Bambu Lab macht daraus 260 Grad Celsius und 250mm/s. Dass einfach zu schnell nachgedrückt wird, obwohl das Filament nicht fließfähig genug ist.
I have the same problem with my P1S, which is only 2 weeks old. Since an AMS is also installed, this is also affected; since a filament drive is also installed, blockages occur at the hotend, the Xtruder head and the AMS extruder. The filament cannot be retracted or inserted into the hotend, so the extruder drive wheels disassemble the filament.
I’ve actually already found the reason - the space between the hotend and the extruder, where the filament cutter works. If too much filament is pressed in, it can spread and cool down, which leads to this plug. In my opinion, this is an undesirable development.
It may also be due to the speed that Bambu Lab specifies for generic filaments. According to the manufacturer, the “Extruder ASA”, for example, should be printed at 225 to 240 degrees Celsius and 40mm/s. Bambu Lab turns this into 260 degrees Celsius and 250mm/s. That the pressure is simply pressed too quickly, even though the filament is not flowable enough.