The error says: “Failed to extrude the filament, Please check if the extruder is clogged”
When I go check at the printer and press “Retry” the AMS retracts the filament and I can see that the AMS has eaten chunks out of the filament, this causes burrs on the filament which can not pass though the AMS feeder, causing an error.
To continue printing I have to take the filament out of the feeder and cut almost 1 meter of the filament (which shows 3-4 grinding marks), re-insert into the feeder en then it extrudes fine for another 10 minutes.
Judging by the direction of these burrs, the grinding of the filament happens during forward feeding, not on retractions.
The issue happened mostly on slot 1, but the rest of the slots also have this issue.
I have taken the entire AMS apart, disassembled the feeder, the manifold and all the tubing.
There was a lot of the grinded filament in the manifold and the feeder which I cleaned.
The issue was not solved by this.
Then I took the hotend apart, replaced the blade, cleaned the extruder but this also did not solve the issue.
My guess is that there is something with the buffer which sends a signal to the AMS to feed filament to the extruder while the extruder is not asking for more filament but I have not caught the buffer getting stuck or something yet…
Or it might be the filament sensor in the print head, if this does not detect filament, the AMS keeps feeding, causing grinding of the filament.
Schau mal bitte an den Schlauchenden (Pfeile vom Bild)
In einer Deutschen Community wurde berichtet, dass in der Verteilung des AMS intern die Schläuche geknickt waren und das Filament die Schläuche dann mit der Zeit aufreißt. Da kam es dann auch zu solchen Fehlern.
Greetings from Germany.
Please look at the hose ends (arrows in the picture)
In a German community it was reported that the hoses were kinked internally in the distribution of the AMS and the filament then tears open the hoses over time. Then there were errors like this.
Yesterday I replaced the extruder and took apart the buffer and cleaned it, I also applied a thin film of grease on the moving parts of the buffer to prevent the slider from getting stuck while moving.
I started my 6,5 hour print again and it printed fine for the first 44% which is longer than any of my previous attempts, but again it gave the same error…
I think i’ll just open a ticket to customer service…
Waren bei dir die Schläche 100% in Ordnung? Wann hast du deinen X1 bekommen?
Nur dass ich da mal schaue ob das mit den geknickten Schläuchen einmalig war oder das bei einem gewissen Auslieferungsdatum anfängt.
Yes. Open a ticket.
Were your hoses 100% okay? When did you get your X1?
I just want to see if the kinked hoses were a one-time thing or if it starts with a certain delivery date.
I just had this problem to today and went through most of the same teardown except tearing into the AMS. But my filament was looking just like yours. It’s like there is too much tension on the filament. there needs to be a tension control with a spring or something.
As best I could see the orange filament fed through the buffer ok then got stuck before it reached the extruder or it didn’t know it reached the extruder because the filament detection switch above the extruder isn’t working.
In this state I would disconnect the buffer input and manually feed some filament checking it easily feeds all the way to the extruder. The on screen extruder display has a green light showing filament present.
I am having the exact same issue and my filament looks like yours. Initially I thought it was it was a single slot (initial slot 3), but I moved the effected color to another slot (slot 4, after cutting off any parts that were ground down) and reprinted the model. It seems like it’s happening with the new slot as well. The other two slots (1 & 2) have no issues. Were you able to get a response from your ticket?
I had the same error a few times now but thought it to be a winding issue. Each time it happened the filament was taken from the side of the spool. I got the impression that the windings were overlapping and thus blocking the filament. Turning the spool by hand to create some slack until the filament was taken more from the center of the spool worked in my case.
I have not had a response from BL yet.
I found out that the issue occurs after around 3 hours of printing, shorter prints print fine without issues.
If the printer is powered off for the night and I start another print the next day, it prints fine again for 3 hours before the issue starts happening again and then it happens around every 15-20 minutes.
@stevehinze57 The feeding wheel inside the AMS has its tension controlled by a spring, but its not adjustable.
@froboz I have replaced the entire extruder including the filament sensor but this did not fix it.
I will keep an eye on the green light, maybe the connection to the toolhead PCB is bad, or the entire PCB is bad.
Maybe you have a temperature dependant fault in the head and it takes 3 hours to warm up. It is not unusual for dry solder joints to not go open circuit till a bit of thermal expansion has occurred.
I had a similar problem and found it was the Extruder feed magnet sensor. There’s a little reed type switch which talks to the ams. Found that it was catching on a piece of swarf on the casing. Smoothed it out and no more issues. Mine also was causing ams feeder to grind at the filament.Hope this helps
Bambu Lab Customer service has shipped me a new drive gear, which is the feeding gear in the AMS manifold.
When replacing this gear I noticed a lot of plastic grindings in the housing for this gear.
After cleaning this and replacing the gear unit I was able to print a 3 day model with over 1300 color changes without issues!
I am not sure if it was the gear that caused issues or the plastic residue that was in there but my issue is solved!
I have seen similar issues with my AMS and there were two causes, first one was the reel I was using, Prusament PETG, on one side of the reel itself was 2mm wider than on the other side, this caused the reel to intermittently hang on a small piece of plastic protruding from the sides of the holder that stop the reel from running off the rollers. It was intermittent and it wasnt happening to any other prusament reels, but it would cause the AMS to stop feeding the reel, but not before running it in and out several times, wearing down the filament itself. Solution don’t use that reel, make sure reels are no more than 69mm wide all the way around, don’t just measure one side. Also added an adapter to the PTFE going into the extruder to stop the PTFE from bending too much.
Second issue was with iMetrx PLA Silk filament, it would print fine, but from time to time doing multi colored printed where there would be multiple filament changes, the AMS would eventually start to shred the filament inside the AMS and it would get jammed in the extruder, or the PTFE or the AMS Hub. There would be bits of filament everywhere. Solution, use high quality filament that is less prone to shredding, ones I have had success with, eSun, SunLu, and Prusa (as long as the reel is not to wide). Also I had to replace the filament cutter blade because it very quickly stopped working with this iMetrx filament and cause the filament to snap apart in the extruder when it was being retracted by the AMS meaning the next feed would fail until you cleaned out the extruder.
Also had some success with BambuLab filament, but I don’t have much and haven’t used it much. I did have issues with the PLA-CF snapping and jamming.
Generally I have had little to no issues when printing single color prints using the AMS, the problems start with multi color prints where its constantly feeding and pulling filament. If you want my opinion, I think the AMS gears heat up with lots of feeding and pulling and if your filament is not up to it, it can start to degrade in the heat and shred and snap. Some form of cooling the AMS would probably help.
Hope this helps, but overall the AMS is a sensitive system, and can easily fail. You certainly can’t just throw in any filament you want, you really need to think it through. Also I would advise keeping some spare PTFE, Feeder and gears just in case.
I’ve been having grinding in my AMS as well, and the only thing I could see wrong was that this gear shown here had the outermost bearing busted open. I don’t know if it’s causing the problem, but it seems to be the best bet so far. Awaiting word from Bambu.
I have been trying to do some ‘upgrade’ research as I have also had this issue and wanted to try and find a way to use software filaments in the AMS. Research below.
