Heatcreep with ASA : extruder gear clogged

Bambu Lab P1 Series Troubleshooting
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Hi everyone,

I’m having major issues printing ASA Formfutura ApolloX on my Bambu Lab P1S.

My problem:
Roughly one out of every three prints fails. Either the nozzle stops extruding, or the filament gets completely deformed and crushed at the extruder gear.
In some cases, the filament even totally clogged the extruder gear
Printing parameters:

*Nozzle temperature: 235°C (manufacturer recommends 235-255°C)
*Bed temperature: 100°C for the first layer, 95°C for the rest

What I’ve already tried:

  • I initially suspected a heat creep issue.
  • To counter that, I lowered the extrusion temperature to 235°C, but I don’t think I can go lower for ASA.
  • I’m also wondering if this lower temperature might actually increase back pressure in the nozzle and contribute to clogging.
  • I tried opening the top cover of the P1S to reduce the internal chamber temperature, but I’m still getting the same problem.
  • I also slightly loosened the extruder gear tension, but that didn’t fix it.
  • I’m concerned that opening the enclosure too much could cause poor layer adhesion with ASA.

Additionally, it’s currently hot in my apartment, around 30°C, and inside the printer when idle, temperatures can reach 30-36°C. I wonder if this contributes to the issue.

At this point, I don’t know if I should further loosen the extruder gear tension, lower the bed temperature, or try something else entirely.

I’m running out of ideas and would really appreciate your help.
If anyone has faced similar issues or has suggestions, I’d be very grateful.

Let me know if you need more info or pictures to help diagnose the issue.
Thanks in advance.

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Are you sure the plastic you print is ASA, not some kind of blend or plastic alloy?

I print sunlu + no-name ABS around 270-275°C, while bed temp cranked to the max 100°C. I would increase bed temp to 110°C if I could. I’ve never had heat creep issue with ABS and I print mostly ABS. I even have an insulated enclosure to sit P1S inside, to improve chamber temperature control.

I, for once, bought an ABS+ roll from ebay, turned out it became soft like ramen at 60°C, while ABS can withstand around 90-110°C. Obviously it clogged every single print when I printed with ABS profile. Then I changed to PLA profile, it printed just like PLA.

Anyway, your picture is too small, can’t really see how plastic stick around the extruder gear.

1 Like
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I’ve had exactly one clog with my X1C, printing PLA-CF. I disassembled the extruder and then, partly because I did not notice the original tension setting, mostly because of lack of guidance from the wiki, I reinstalled the tensioner spring fully compressed.

In the past two years. I’ve had no clogs or extrusion issues printing PLA, PLA-CF, PETG, TPU 95, ASA, PC, or PA6.

Maybe reducing tension is allowing the filament to slip and clog?
Maybe there is a reason the cover has no access hole?