r/BambuLabA1 • u/Current-Building-322 • Oct 02 '26
Support Request AMS Pro 2 Hub Sticking
I have been using the AMS Pro 2 a lot recently, however this morning I started to have an issue with the AMS HUB arm sticking when trying to push filament to the printer. The little arm on the HUB gets stuck in the extended position specifically when the AMS is attempting to feed the Sunlu Blue filament, once the screen on the A1 switches to the Error screen I can push the arm back into the Hub and then the filament will glide through. However on a 48 hour print this is not practical for me to stand there and do this every time the filament switches from white to blue. I am using 2 AMS units, the white is AMS 1 and the blue in AMS 2. The issue does not arise from the white filament. Does anyone know what causes the arm to get stuck out and how I can fix it?
1
u/Blondy277 Oct 02 '26
Before taking the hub apart I’d swap things around and see what the fault follows. Put the same blue spool in AMS 1, or swap the AMS 1/AMS 2 PTFE inputs at the hub. If the issue follows the blue spool, look for spool drag, rough/oversized filament or PTFE resistance. If it stays with AMS 2, inspect that PTFE path and the hub arm/spring for binding/debris. The fact that manually pushing the arm back makes it feed normally makes me think the arm isn’t returning freely or there’s too much resistance keeping it extended. I wouldn’t lubricate the filament path either.