Hey everyone,  
I’m having a persistent issue with my Bambu Lab H2C and I’m hoping someone here might have an idea what’s going on.

My prints consistently fail at a specific height because the nozzle starts colliding with the printed part. This happens around layer 345. I ran a tower printing test, and every layer is printed in a clearly visible spiral motion starting from the center. At layer 345 there’s an immediate change: the nozzle begins pressing into the tower and smearing the filament.

Other test prints show the same behavior. During the overhang test, the nozzle scratches the overhanging part and sometimes colides with the edge. Some prints get knocked over. An octopus print I did about a week ago failed at exactly this height as well — I had to reprint the top of the head and glue it on. That was my first print failure and I first realized something was wrong. Before that, I never printed anything tall enough to reach this height. I have the same problems with the left nozzle at layer height 345 (0.2 mm layer height) and right nozzle at 10 mm higher.

It’s definitely not an adhesion issue. I cleaned the textured PEI plate exactly as recommended. The same problem also happens with the right nozzle, just at a slightly higher layer. I'm not sure about heat creep since I could reproduce this issue with both the door closed and open door and 100% on all coolers.

Has anyone experienced something similar or has an idea what could cause this? It is a bit disappointing for 3 weeks old 2300€ printer.

Strange height‑dependent nozzle collision on my new H2C