I know this has been asked before, but I wanted to see if the community had any other sage advice…
I unpacked the P1P yesterday after a move to a new location, got everything setup. Calibrated the machine, loaded PLA to make sure it was all working, everything looks good.
Hooked up the AMS and immediately upon attempting to load filament, I get the 'Failed to pull back the filment from the tool head to AMS". It walks through the steps and then pulls the filament back out, but the indicator on the app shows that the print head is clear.
I know the filament sensor in the print head is working, I was able to test that. Normal loading seem fine, all the tubes are clear and there is nothing in the AMS that I can see.
I’m not sure where to go from here, you would think because the print head shows that it has no filament loaded it would not need to do the pullback and just move straight to load. So right now I have an expensive paperweight that will not load filament, I opened a ticket but apparently they are incedibly backed up and I expect the response will be to look at the Wiki’s…
Could this be a software issue, I don’t think we can roll back to previous versions?
I’ve had mine get in a weird loop like that a few times. I just did a power cycle and everything was fine after.
I’ve also had a piece of filament break in between the sensor in the head and the extruder which causes similar behavior. In that case just remove the PTFE tube from the print head and manually insert some filament and use the printers controls to run some filament through the extruder. Kind of similar to how you do a cold pull.
So I took apart the AMS and made sure all the lines where clear, there was some in 2 and 3 but one seemed clear. Put it all back together and reset everything, I checked the head and if I insert filament the sensor shows green and white when I pull it out.
I also fed some directly into the print head and cleared it that way…
Nothing seems to make any difference, but like I stated, I can load filament manually and everything works.
I’ll keep tinkering and hope that Bambu will get back to me, I saw someone state that an override option would be good and I agree. To me this feels like a software issue…
I had exactly the same problem on brand new P1S. I contacted Bambu Lab support and they helped me to investigate, they even sent me spare part at the end.
My problem was with filament buffer. I dissembled and cleaned it, also made sure tubes are not touching the wall behind. Check that you can easily pulll one of the 2 tubes attached to the filament buffer and when you release, the spring should pull it back
I did solve this issue finally, Bambu was not much help. Turns out that a piece of filament broke off in the AMS unit. To fix that I had to disassemble the unit, turn it over and pull the 4 PTFE Tubes, then I pressed on the spring clamp and used a fresh piece of filament to force out the broken piece. Once I cleared that, everything worked perfecty.
I am glad that the issue is solved, and thanks for sharing.
That’s a typical event in the AMS (at least for me). Sometimes, the filament breaks inside, and you must disassemble and remove it.
What I didn’t understand was where your filament was broken. In the hub or the feeder?
@okokok, thanks for the picture and for sharing the experience.
For me, it occurred that when I made space in the AMS for a different filament and then put the old one back in (Amazon basic) after taking it out, it always had those ridges from the pull-in motor.
After cutting off the part with the ridges it worked again for me
Mine filament broke under the AMS had to disassemble the whole AMS top layer to get under the ptfe tube to release. and pull the filament out. first time looking under the ams, those ptfe tube on slot 4 and 1 takes quite a tight turn to get to the extrusion point of the AMS.
I could see the printer thought filament was loaded. I had found a piece of filament that had broken (brittle towards the end) and removed it and it still thought there was more. I did cold pulls, etc trying to clear it. Finally figured it had to be in the bottom of the AMS. It was…
So I also have this error message, but in my opinion I don’t have a broken filament
I checked all PTFE tubes by hand for friction, partially replaced them and also optimized the bending radii.
If I remove the PTFE tubes at the moment the problem occurs and pull the filament in different places by hand, then it is between:
Extruder and buffer = smooth running
Buffer - AMS = difficult to move
The filament can be easily pulled out of the extruder manually, the bottleneck is somewhere after it. I have already dismantled and examined the buffer, but the functionality is not so clear to me either.
I have two AMS and that happens with both AMS. What speaks against a broken filament in the AMS.
My issue was quite different. But, the replies here have been helpful. At first, I checked through the ptfe tubes. This is an important check to identify if any filaments still stuck inside. Highly recommended step. For me, there was no filament stuck in the ptfe tubes, including those in the ams. omg!
Then, I isolated to this “feeder” part. Its the feeder where four of the ptfe tubes come together. Forum blocked me from sharing media. Anyway, should be able to spot it once you dismantle the ams and see the underneath. I tried to slot in a filament through 4 of the tubes linked from the individual spools. Turned out that there was some unusual blockage. Then, I had to partially dismantle this “feeder” (shown in the pic). Turned out that there was a piece of filament which broke off and it was somewhat crooked. Using a fine long screw driver is sufficient to pry this damn stray filament stuck inside.
Moral of the story is use good quality filament and ensure that the filament doesn’t have any usual twists when first insert into the ams. Simple, but unobvious to me. I’m in my first of ownership.
Filament dryer is a must have to minimise the risk of blockage. Took me one morning to trouble shoot this. At least all is well.
I purchased my P1S a few weeks ago with the AMS. Has been printing find with PETG but changed to PLA last night to print another model. AMS loaded filament, bed levelling was fine and printer started printing but no filament was being extruded. I stopped the print and the AMS tried to unload the filament but failed.
I disassembled the AMS and removed the filament which was stuck between the AMS and AMS buffer and the AMS now loads the filament as far as the AMS buffer but then gives intermittent movements like it is trying to feed filament. This continues for 3-4mins but then the AMS unloads the filament and gives an error that it can’t be loaded.
I’m guessing there is a blockage between the AMS buffer and the hotend but have not had time to investigate further.
Would it be best to remove the hotend and check for blockages from that end or to diassemble the AMS buffer and check for blockages there?
I know this is an old thread, but I have the same problem … I have replaced the internal AMS hub feeder. I don’t have filament stuck anywhere. I get the failed to pull back message, then spool feeder goes red because it can’t move. I shut power off. Power back up, tell it to unload filament, and it pulls back into the AMS just like it should, every time. Fails during a print, but works fine after a power cycle. What is this ■■■■? I’ve also tried some of the “fixes” from MakerWorld … no help there.
I, too, had this same problem with filament from 3DFuel. Seems that the spools that 3DFuel uses are a tab bit larger, and when you put the top of the AMS down and lock it into place, it binds the spool so that it can not retract. My solution is to put the locking tabs in place and set the AMS lid atop them so that the lid is raised up a bit. Not a great solution, but it allows me to use the filament.
I would hope that Bambu Labs would see fit to make the lid a tab bit larger to accommodate a variety of spools, but I would not bet a kidney that they will.
Don’t know if this is your problem or if you have a hardware issue, but be aware that not all spools are the same size and a fraction can mean a BIG difference.
The buffer is easy to disassemble just don’t disassemble the AMS hub that is internal to the AMS, that has 4 small magnets and springs that will go flying as soon as you open it up.
