Problem: Pause parks the toolhead at increasingly higher Z after each pause — Z motor eventually skips and ruins the print
Firmware Version: 01.08.01.00
Printer: Bambu Lab A1
Steps to reproduce:
- Slice a model with ~100 manual pauses or filament changes (no AMS, “Change filament G-code” = “M400 U1”)
- Start the print
- At each pause, observe that the toolhead parks higher and higher on the Z axis
- After enough pauses, the Z axis reaches its physical limit and the Z motor skips/grinds, ruining the whole print
Other information:
No AMS / AMS Lite — single external spool, manual filament changes only.
After each pause the print itself resumes correctly (the toolhead returns in XY to the last position and lowers to the correct layer height). Only the PAUSE-PARK Z height climbs linearly with every pause/resume cycle, so the firmware appears to keep an internal Z that is raised by the park lift and is never reset on resume.