The filament is jamming on the AMS lite preventing it to get pulled properly from the hotend. Why is this happenning? It seems to be more frequent with matte PLA (although it happened with galaxy PLA also). Maybe the extruder motor is too hot and the heat are smoothing the filament just under the AMS hub and then creating this jam when pushing? Or maybe too resistance from the bowden tubes? It does not seem to be heatcreep as the jam happens way above the cold end.
The color change process have two motors that work to move the filament. The extruder gears retract the filament from the hotend, then when it’s cut, the ams motor pull back the filament. I think the jam happens on the first phase.
PS: I am using the long retraction option but I am pretty sure that already happened before I turned this on.
Profile: default
I am having the same issue as well. in my case I am using Bambu PETG-HF. we are doing 4 filament color prints. we found that it has only been happening to us in #3 spot.
Hey there, I was looking into online solutions to keep the stepper motor cooler and noticed a lot of people recommend adding an extra fan. I wanted to try a slightly simpler and less invasive approach, so I stuck a few small heatsinks on both sides of the motor. Surprisingly, I haven’t had any failures since then. Coincidence or not? Only time will tell!
Coming back with an update: even with the heatsinks I am still getting some jams (failed to pull back the filament from the toolhead). I did realize that I get this only on slot 4 and mostly with matte PLA.
My hypothesis continue the same, the filament gets deformed when the gears push back the filament. I think there is some resistance on the way back on this specific slot/bowden tube, combined with the softness of matte PLA, the filament gets deformed and gets tucked. I will probably disassemble the AMS hub and check the bowden tube.
