My AMS 2 Pro cannot feed any filament from any slot. When it reaches the 4:1 hub within the unit it stops. I can hear a motor running in the back of the hub, and the filament sounds like a repeating grinding sound…like the end of the filament is trying to enter a geared passageway but it is blocked, so the grinding is about ½ second on and ½ second off, as if it is constantly trying to push the filament into a motorized assist, but that passageway is blocked.
Is there any way to open this up and see and clear the blockage? Or does the 4:1 hub need to be replaced? Is there any known answer for this problem?
I turned in a support ticket to Bambu and have not heard anything…they are true to their support reputation–and it is frustrating having this in-warranty machine unusable and no support being available.
Any suggestions?
(I tried to upload the movie so you could hear the repeated grinding sound, but it wouldn’t accept MOV files.
I’m guessing you tried a different port on the 4 port side and the same happens?
Are the tubes going in and coming out of the hub fairly straight?
Have you tried a different filament?
Same issue. I have to push down on the button on the hub (AMS 2 Pro) and push the filament through. It may work for a few changes, then jam up again and not make it through.
I am having this issue as well! brand new AMS and it is not feeding past the 2nd drive motor. took it apart and checked all wiring connections and plugs. I can manually turn the 2nd drive motor and get the filament to feed when it is apart. guessing maybe the 2nd drive motor is bad?
I just took my internal hub apart and cleaned it and this seems to have fixed the issue! really surprising this was the issue because it was a brand new AMS. took it apart, cleaned it and its working now!!!
followed these instructions. you need to make sure when the filament contacts the magnets inside the hub, that there is minimal pressure required to push the magnet up to the sensor. mine was just a little crumby inside and cleaning it allowed the magnets to lift smoothly.
I’ve cleaned the filament hub per the wiki and am still getting this issue. Filament from any slot will not move past the hub even if I hold down the button. This thing is driving me crazy.
I wound up having an issue with this after owning an AMS 2 Pro for about 8 months and 1250 printer hours, with few prints that have tons of color changes.
For me, the cause of my issues was not debris. Instead, it seems like something had caused the idler/spring tensioner to get very slightly offset. After disassembling, cleaning, then reassembling, the problem persisted.
I decided to mess around with it a bit after pulling out the internal hub again. it seems like, somehow, the bolt/pin that the idler pivots around has developed more slop than it should have. It can move about a millimeter in either direction, and rotate/bind slightly. This causes the upper idler hobbed pulley to come out of alignment with the lower motor hobbed pulley. This very slight misalignment causes filament to be blocked from passing, and causes tons of resistance when it does manage to pass.
What has worked for me so far is:
Take out the internal hub following the cleaning/disassembly guide
Loosen the idler bolt
Wiggle the idler/spring loaded button
While wiggling, slide some filament all the way through the internal hub.
Tighten the idler bolt while filament is inside the assembly
The wiggling will allow the upper and lower pulleys to properly align and the filament will go through. Tightening the idler bolt while the filament is inside ensures proper alignment, because the filament forces everything in to alignment when it is inside.
Separate, but probably related issue. The idler bolt seems like it has pretty badly stripped out the threads in the hub housing, which may be the cause of the slop in the first place for my situation.
Solved for the moment* I pulled out the back tube of the 4-1 hub, and blew a little bit of pressured air up both sides. that solved it for now. it was failed on every signal filament switch before hand. Mine worked for the first 4 days of printing before just quitting.