Cooling Fan

Configure part cooling fan behavior and performance.

Fan Max Speed

Parameter
fan_max_speed
Unit
Percentage (%)
Range
0 - 100%
Default
100%
Description
Maximum speed the part cooling fan can run at. Some fans may be too powerful at 100%.

Fan Min Speed

Parameter
fan_min_speed
Unit
Percentage (%)
Range
0 - 100%
Default
35%
Description
Minimum speed below which the fan won't spin reliably. Set this to prevent fan stalling.

Auxiliary Fan

Parameter
auxiliary_fan
Description
Enable if your printer has a secondary (auxiliary) cooling fan for additional airflow.
Note
Common on Bambu Lab printers with dual part cooling.

Fan Kickstart Time

Parameter
fan_kickstart
Unit
Seconds
Default
0
Description
Run fan at full speed briefly before reducing to target speed. Helps fans overcome startup inertia.

Understanding Part Cooling

Part cooling is essential for print quality but varies by material:

MaterialRecommended Fan %Notes
PLA80-100%Maximum cooling for best results
PETG30-60%Moderate cooling, too much causes layer adhesion issues
ABS0-20%Minimal cooling, prevents warping
TPU30-50%Moderate cooling
ASA0-30%Low cooling, similar to ABS
Nylon0-30%Minimal cooling for layer adhesion

Related Settings

Fan speed is also configured per-material in the Material Settings: