Klipper macro for semi-automated `rotation_distance` calibration

README.md

Klipper Extruder Calibration Macros

Why?

Klipper and Mainsail lack built-in extruder calibration. These macros automate it.

How It Works

1. Mark the filament at 120mm before running the macro.
2. Run:

   EXTRUDER_CALIBRATION
   

   • Heats nozzle, moves to center, extrudes 100mm, then cools down.
   • Measure remaining filament.
3. Enter measured value:

   SET_EXTRUDER_CALIBRATION MEASURED_LENGTH=<your_value>
   

   (Replace <your_value> with the actual measurement.)
4. Update printer.cfg manually with the new rotation_distance shown.

Example Output

Starting calibration...
Extruding 100mm...
Measure remaining filament and enter:
SET_EXTRUDER_CALIBRATION MEASURED_LENGTH=<your_value>

Old rotation_distance: 7.50
New rotation_distance: 8.62
Update printer.cfg manually!

Notes

• Macros can’t pause for input, so it’s split into two steps.
• No auto-saving to printer.cfg, manual update required.

macro.cfg

[gcode_macro EXTRUDER_CALIBRATION]
description: "Start extruder calibration"
gcode:
    RESPOND MSG="Starting calibration, make sure you already marked the 120mm spot on the filament"
    RESPOND MSG="Pre-heating nozle"
    SET_HEATER_TEMPERATURE HEATER=extruder TARGET=200

    RESPOND MSG="Moving to save position"
    G28
    G90
    {% set bed_x = printer.configfile.settings.stepper_x.position_max|float %}
    {% set bed_y = printer.configfile.settings.stepper_y.position_max|float %}
    {% set center_x = bed_x / 2 %}
    {% set center_y = bed_y / 2 %}
    G1 X{center_x} Y{center_y} Z100 F6000

    RESPOND MSG="Waiting for nozle to be hot enough"
    TEMPERATURE_WAIT SENSOR=extruder MINIMUM=200
    
    RESPOND MSG="Extruding 100mm"
    G91
    M106 S100
    G1 E100 F100
    M106 S0
    G90

    RESPOND MSG="Extursion finished, cooling down"
    TURN_OFF_HEATERS

    RESPOND MSG="Measure remaining filament and enter: SET_EXTRUDER_CALIBRATION MEASURED_LENGTH=your_value_in_mm"


[gcode_macro SET_EXTRUDER_CALIBRATION]
description: "Calculate new rotation_distance"
gcode:
    {% if params.MEASURED_LENGTH|float > 0 %}
        {% set requested_extrude_distance = 100 %}
        {% set initial_mark_distance = 120 %}
        {% set subsequent_mark_distance = params.MEASURED_LENGTH|float %}
        {% set actual_extrude_distance = initial_mark_distance - subsequent_mark_distance %}
        {% set previous_rotation_distance = printer.configfile.settings.extruder.rotation_distance|float %}
        {% set new_rotation_distance = previous_rotation_distance * actual_extrude_distance / requested_extrude_distance %}

        RESPOND MSG="Old rotation_distance: {previous_rotation_distance}"
        RESPOND MSG="New rotation_distance: {new_rotation_distance}"
        RESPOND MSG="Update printer.cfg manually!"
    {% else %}
        RESPOND MSG="ERROR: No valid measurement provided!"
    {% endif %}