klipper-macros/macros/heating/bed_fans.cfg

# Bed fans driven by the bed heater (based on Ellis' bed fan macros)

############### Config options ##################

[gcode_macro _BEDFANVARS]
variable_threshold: 50		# If bed temp target is above this threshold, fans will be enabled. If temp is set to below this threshold, fans will be disabled.
variable_fast: 1.0		# Fan speed once bed temp is reached  
variable_slow: 0.5		# Fan speed while bed is heating
variable_cooldown_temp: 40   # NEW: fans stop below this temp
gcode:

########## Aliases #########

[gcode_macro BEDFANSSLOW]
gcode:
	# Vars
	{% set SLOW = printer["gcode_macro _BEDFANVARS"].slow|float %}
	
	SET_FAN_SPEED FAN=BedFans SPEED={SLOW}

[gcode_macro BEDFANSFAST]
gcode:
	# Vars
	{% set FAST = printer["gcode_macro _BEDFANVARS"].fast|float %}
	
	SET_FAN_SPEED FAN=BedFans SPEED={FAST}

[gcode_macro BEDFANSOFF]
gcode:
	SET_FAN_SPEED FAN=BedFans SPEED=0

############ Command overrides ############

# Override, set fan speeds to low and start monitoring loop.
[gcode_macro SET_HEATER_TEMPERATURE]
rename_existing: _SET_HEATER_TEMPERATURE
gcode:
	# Parameters
	{% set HEATER = params.HEATER|default("None") %}
	{% set TARGET = params.TARGET|default(0)|int %}
	# Vars
	{% set THRESHOLD = printer["gcode_macro _BEDFANVARS"].threshold|int %}
	{% set COOLDOWN = printer["gcode_macro _BEDFANVARS"].cooldown_temp|int %}
	
	{% if HEATER|lower == "extruder" %}
		M104 S{TARGET}

	# {% elif HEATER|lower == "iHeater_H" %}
	# 	_SET_HEATER_TEMPERATURE {rawparams}

	{% elif HEATER|lower == "heater_bed" %}
		M99140 S{TARGET}

		# Always cancel cooldown loop first (prevents overlap)
		UPDATE_DELAYED_GCODE ID=bedfancooldown DURATION=0

		# --- NEW LOGIC BLOCK ---
		{% if TARGET == 0 %}
			# Bed turning off → start cooldown behavior
			{% if printer.heater_bed.temperature|int > COOLDOWN %}
				BEDFANSSLOW
				UPDATE_DELAYED_GCODE ID=bedfancooldown DURATION=5
			{% else %}
				BEDFANSOFF
			{% endif %}

			# Stop normal heating loop if running
			UPDATE_DELAYED_GCODE ID=bedfanloop DURATION=0

		{% elif TARGET >= THRESHOLD %}
			# Heating above threshold
			BEDFANSSLOW
			UPDATE_DELAYED_GCODE ID=bedfanloop DURATION=1

		{% else %}
			# Low temp request
			BEDFANSOFF
			UPDATE_DELAYED_GCODE ID=bedfanloop DURATION=0
		{% endif %}
		# --- END NEW LOGIC ---

	{% else %}
		# {action_respond_info("(Bedfans macro)Heater %s not supported (trying classic _SET_HEATER_TEMPERATURE)" % HEATER)}
		_SET_HEATER_TEMPERATURE {rawparams}
	{% endif %}
	
# Override M190 (Wait for Bed Temperature)
# As a bonus, use TEMPERATURE_WAIT so we don't have to wait for PID to level off.
[gcode_macro M190]
rename_existing: M99190
gcode:
	# Parameters
	{% set S = params.S|int %}
	# Vars
	{% set THRESHOLD = printer["gcode_macro _BEDFANVARS"].threshold|int %}
	
	{% if S >= THRESHOLD %}
		BEDFANSSLOW																# >= Threshold temp: Low speed fans while heating 
	{% else %}
		BEDFANSOFF																# < Threshold temp: Turn bed fans off
	{% endif %}                                        

	M140 {% for p in params
	  %}{'%s%s' % (p, params[p])}{%
	  endfor %}																	# Set bed temp
	  
	{% if S != 0 %}
		TEMPERATURE_WAIT SENSOR=heater_bed MINIMUM={S|int} MAXIMUM={S|int + 5}	# Wait for bed temp within 5 degrees
	{% endif %}

	# Post-heating fan speeds
	{% if S >= THRESHOLD %}								    
		BEDFANSFAST																# >= Threshold temp: Higher speed fans after heating finished
	{% endif %}
	
# Replace M140 (Set Bed Temperature) to just be an alias of SET_HEATER_TEMPERATURE (which has associated bed fan logic if enabled)
[gcode_macro M140]
rename_existing: M99140
gcode:
	# Parameters
	{% set S = params.S|float %}
	
	SET_HEATER_TEMPERATURE HEATER=heater_bed TARGET={S}
	
# Replace TURN_OFF_HEATERS
# [gcode_macro TURN_OFF_HEATERS]
# rename_existing: _TURN_OFF_HEATERS
# gcode:
# 	BEDFANSOFF
# 	_TURN_OFF_HEATERS
[gcode_macro TURN_OFF_HEATERS]
rename_existing: _TURN_OFF_HEATERS
gcode:
	# Vars
	{% set COOLDOWN = printer["gcode_macro _BEDFANVARS"].cooldown_temp|int %}

	# Only keep fans running if bed is still hot
	{% if printer.heater_bed.temperature|int > COOLDOWN %}
		BEDFANSSLOW
		UPDATE_DELAYED_GCODE ID=bedfancooldown DURATION=5
	{% else %}
		BEDFANSOFF
	{% endif %}

	_TURN_OFF_HEATERS
	
################ Monitoring loop #####################

# Turns bed fans to "fast" speed once target bed temp is reached.
[delayed_gcode bedfanloop]
gcode:
	# Vars
	{% set THRESHOLD = printer["gcode_macro _BEDFANVARS"].threshold|int %}
	
	{% if printer.heater_bed.target >= THRESHOLD %}								# Continue only if target temp greater than threshold.
		{% if printer.heater_bed.temperature|int >= (printer.heater_bed.target|int - 1) %}
			BEDFANSFAST															# If within 1 degree of target temp: Higher speed fans
		{% else %}
			UPDATE_DELAYED_GCODE ID=bedfanloop DURATION=5						# If temp not reached yet: loop again
		{% endif %}
	{% endif %}

[delayed_gcode bedfancooldown]
gcode:
	# Vars
	{% set COOLDOWN = printer["gcode_macro _BEDFANVARS"].cooldown_temp|int %}

	{% if printer.heater_bed.temperature|int > COOLDOWN %}
		BEDFANSSLOW
		UPDATE_DELAYED_GCODE ID=bedfancooldown DURATION=10
	{% else %}
		BEDFANSOFF
	{% endif %}