Purge on print start

print_macros.cfg

[gcode_macro PRINT_START]
description: A wrapper that initializes a toolchanger by homing and then passes to real one
gcode:
  M117 Pre-homing to init toolchanger
  G28
  {% set target_bed = params.BED|int %}
  {% set target_extruder = params.EXTRUDER|int %}
  {% set target_chamber = params.CHAMBER|default("40")|int %}

  {% set tool_n = params.TOOL|default("0") %}
  {% set t0_temp = params.T0_TEMP|default(0)|int %}
  {% set t1_temp = params.T1_TEMP|default(0)|int %}
  {% set t2_temp = params.T2_TEMP|default(0)|int %}

  M117 Passing over to _PRINT_START (_PRINT_START BED={target_bed} EXTRUDER={target_extruder} CHAMBER={target_chamber} TOOL={tool_n} T0_TEMP={t0_temp} T1_TEMP={t1_temp} T2_TEMP={t2_temp})
  _PRINT_START BED={target_bed} EXTRUDER={target_extruder} CHAMBER={target_chamber} TOOL={tool_n} T0_TEMP={t0_temp} T1_TEMP={t1_temp} T2_TEMP={t2_temp}


[gcode_macro _PREHEAT_HEAD_TO_TEMP]
gcode:
  {% set tool_temp = params.TARGET|default(0)|int %}
  {% set tool_index = params.TOOL_INDEX|int %}
  {% set tool_name = printer.toolchanger.tool_names[tool_index] %}
  {% set tool = printer[tool_name] %}
  {% set tool_extruder = tool['extruder'] %}
  {% if tool_temp != 0 %}
    M117 Preheating {tool_name} to {tool_temp}
    SET_HEATER_TEMPERATURE HEATER={tool_extruder} TARGET={tool_temp}    
  {% endif %}

  

[gcode_macro _PURGE_DOCK_HEAD]
variable_length: 25
gcode:    
  {% set current_tool = printer.toolchanger.tool_number %}
  {% set tool_index = params.TOOL_INDEX|int %}

  # Avoid purging curent tool, as it is not in the dock
  {% if tool_index == current_tool %}
    M117 Not purging current tool T{tool_index}
  {% else %}
    {% set tool_temp = params.TARGET %}
    {% set purge_length = params.LENGTH|default(length)|int %}
  
    {% set tool_name = printer.toolchanger.tool_names[tool_index] %}
    {% set tool = printer[tool_name] %}
    {% set tool_extruder = tool['extruder'] %}
    
    M117 Purging {tool_name} before printing at {tool_temp}
    TEMPERATURE_WAIT SENSOR={tool_extruder} MINIMUM={tool_temp} ; for selected tool
    ACTIVATE_EXTRUDER EXTRUDER={tool_extruder}
    G91
    G1 E{purge_length} F100
    # cool down to prevent more oozing
    # {% set temp_wait = tool_temp - 20 %}
    # SET_HEATER_TEMPERATURE HEATER={tool_extruder} TARGET={t0_temp}    
  {% endif %}


[gcode_macro _PRINT_START]
description: A real implementation with toolchanger initialized
gcode:
  {% set target_bed = params.BED|int %}
  {% set target_extruder = params.EXTRUDER|int %}
  {% set target_chamber = params.CHAMBER|default("40")|int %}

  {% set tool_n = params.TOOL|default("0") %}
  {% set t0_temp = params.T0_TEMP|default(0)|int %}
  {% set t1_temp = params.T1_TEMP|default(0)|int %}
  {% set t2_temp = params.T2_TEMP|default(0)|int %}

  ### From ktc-easy
  STOP_CRASH_DETECTION
  
  # If there is a heatsoak going, cancel it so it won't cause anything unexpected later
  DISABLE_HEAT_SOAK
  
  # Even though there is a heatsoak routine, save some time and start heating the bed early
  M117 Preparing for the print, preheating bed to {target_bed}
  SET_HEATER_TEMPERATURE HEATER=heater_bed TARGET={target_bed}

   # Preheat all tools too, if their temp was requested
  _PREHEAT_HEAD_TO_TEMP TOOL_INDEX=0 TARGET={t0_temp}
  _PREHEAT_HEAD_TO_TEMP TOOL_INDEX=1 TARGET={t1_temp}

  # Calibrating frame
  # M117 Calibrating frame (QGL -> re-home -> Bed Mesh)
  G90                                                 ; Absolut position
  _LED_STATUS_PREPARING                               ; Add visuals

  M117 Quad Gantry Leveling
  QUAD_GANTRY_LEVEL                                   ; Calibrage gantry with clean nozzle
  G28                                                 ; Home again with clean nozzle for better z precision
  G90                                                 ; Absolut position
  _LED_STATUS_PREPARING                               ; Set status again after re-homing
  M117 Bed Mesh Calibration
  BED_MESH_CLEAR                                      ; Discard old bed mesh and clean nozzle
  BED_MESH_CALIBRATE ADAPTIVE=1                       ; This is done after cleaning nozzle and gantry calibration

  M117 Switching to T{tool_n}
  SELECT_TOOL T={tool_n}

  # Set temperature for the requested tool
  {% set target_tool = printer['tool T' + tool_n] %}
  {% set target_heater = target_tool['extruder'] %}
  M117 Setting target temperature for {target_tool['name']}
  SET_HEATER_TEMPERATURE HEATER={target_heater} TARGET={target_extruder}

  # Purge tools other than main, if temp was requested
  _PURGE_DOCK_HEAD TOOL_INDEX=0 TARGET={t0_temp}
  _PURGE_DOCK_HEAD TOOL_INDEX=1 TARGET={t1_temp}
  # After purging activate back target extruder
  ACTIVATE_EXTRUDER EXTRUDER={target_heater}

  # Wait for target tool's target temperature at safe location
  _BUCKET
  M117 Waiting for printing temperatures (bed: {target_bed}c, extruder: {target_extruder}c)
  TEMPERATURE_WAIT SENSOR=heater_bed MINIMUM={target_bed}
  TEMPERATURE_WAIT SENSOR={target_heater} MINIMUM={target_extruder} ; for selected tool

  ### From ktc-easy
  START_CRASH_DETECTION

  # Main tool is purged to the bucket right before print starts
  {% set clean_macro = printer['gcode_macro _CLEAN_NOZZLE'] %}
  {% set clean_retract = clean_macro.retract_hot + clean_macro.retract_cool %}  
  G92 E0                            ; zero the extruder  
  G1 E{clean_retract} F400          ; that was pulled dufing _CLEAN_NOZZLE
  G1 E100 F400                      ; Instead of purge
  G90                               ; switch to absolute coordinates before printing 
  _SCRUB_NOZZLE

  _LED_STATUS_PRINTING
  M117 Starting the print
  # M118 Starting the print