[FR] When heating up for ABS etc, rotate the parts fan slowly to support convection

[top-gun]

As discussed on Discord, running the fan slowly during the heat-up procedure helps to heat the chamber faster. I do this for all filaments that require more than 85° bed temperature, they need a hot chamber.

[gcode_macro START_PRINT]
gcode:
SAVE_GCODE_STATE NAME=start_print_state
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
G28 ;home
{% if params.BED_TEMP|default(printer.heater_bed.target, true) > 85 %}
M106 S40 ; run Partsfan slow for ABS-like temperatures
{% endif %}
M117 Heating...
M190 S{params.BED_TEMP|default(printer.heater_bed.target, true) }; wait for bed to heat up
M109 S150 ; Wait for extruder to reach 150 so an inductive probe (if present) is at a predictable temp. Also allows the bed heat to spread a little.
Z_TILT_ADJUST ;Adjust bed tilt
G28 ;Home again as Z will have changed after tilt adjustment and bed heating.
BED_MESH_CALIBRATE ; Calibrate bed mesh
G0 X{printer.toolhead.axis_maximum.x -20} Y{printer.toolhead.axis_maximum.y -20} Z0.2 F6000 ; Park in the back and wait for extruder
M109 S{params.EXTRUDER_TEMP|default(printer.extruder.target, true) }; wait for extruder to heat up
M107 ; partsfan off again until Slicer commands it on.
M117 Printing...
RESTORE_GCODE_STATE NAME=start_print_state
M82
G92 E0