PRINT_START Macro Example (Minimal)

This is a minimal PRINT_START macro for StealthChanger using klipper-toolchanger-easy. This version provides the essential functionality without advanced features.

klipper-toolchanger-easy provides a PRINT_START macro by default. This minimal example shows the basic implementation. For advanced features like smart QGL selection and tool detection, see the Advanced PRINT_START Example.

Common StealthChanger Variables

The PRINT_START macro uses several variables that slicers pass:

• TOOL - The initial tool number to use (e.g., 0, 1, 2)
• TOOL_TEMP - The target temperature for the initial tool
• BED_TEMP - The target bed temperature
• T0_TEMP, T1_TEMP, T2_TEMP, etc. - Pre-heat temperatures for additional tools (optional, for multi-tool prints)

[gcode_macro PRINT_START]
description: "Initialize toolchanger, home, QGL, and prepare for printing"
gcode:
    # Initialize toolchanger
    INITIALIZE_TOOLCHANGER

    # Stop tool probe crash detection during startup
    STOP_TOOL_PROBE_CRASH_DETECTION

    # Set bed temperature
    M140 S{params.BED_TEMP|default(60)|float}

    # Home all axes
    G28

    # Select T0 for QGL (always use T0 for final QGL and Z homing)
    T0

    # Heat nozzle to 150C for QGL (softens any leftover filament)
    M109 S150

    # Run Quad Gantry Level
    QUAD_GANTRY_LEVEL

    # Re-home Z after QGL
    G28 Z

    # Stop heating (actual tool will be selected and heated next)
    M109 S0

    # Pre-heat tools that will be used in the print
    {% for tool_nr in printer.toolchanger.tool_numbers %}
        {% set tooltemp_param = 'T' ~ tool_nr|string ~ '_TEMP' %}
        {% if tooltemp_param in params %}
            M104 T{tool_nr} S{params[tooltemp_param]|float}
        {% endif %}
    {% endfor %}

    # Select the initial tool for printing
    {% if params.TOOL is defined %}
        T{params.TOOL|int}
    {% else %}
        T0  # Default to T0 if not specified
    {% endif %}

    # Heat the initial tool to printing temperature
    M109 S{params.TOOL_TEMP|default(220)|float}

    # Restart tool probe crash detection
    START_TOOL_PROBE_CRASH_DETECTION

Parameters

Required: - TOOL - The initial tool number to use (e.g., 0, 1, 2) - TOOL_TEMP - The temperature for the initial tool - BED_TEMP - The bed temperature

Optional (for multi-tool prints): - T0_TEMP, T1_TEMP, T2_TEMP, etc. - Pre-heat temperatures for tools that will be used in the print

Example Usage

Single tool print:

PRINT_START TOOL=0 TOOL_TEMP=220 BED_TEMP=60

Multi-tool print:

PRINT_START TOOL=0 TOOL_TEMP=220 BED_TEMP=60 T0_TEMP=220 T1_TEMP=230 T2_TEMP=250

What This Macro Does

1. Initializes the toolchanger (INITIALIZE_TOOLCHANGER)
2. Stops tool probe crash detection
3. Sets and waits for bed temperature (M140)
4. Homes all axes (G28)
5. Selects T0 for QGL
6. Heats T0 to 150°C for QGL
7. Runs Quad Gantry Level (QUAD_GANTRY_LEVEL)
8. Re-homes Z after QGL
9. Pre-heats other tools if T0_TEMP, T1_TEMP, etc. are provided
10. Selects the specified TOOL and heats it to TOOL_TEMP
11. Restarts tool probe crash detection

Customization

If you need to customize the PRINT_START macro:

1. Do not override it - Instead, modify the macro in stealthchanger/macros.cfg
2. Use hooks - klipper-toolchanger-easy may provide hooks for customization
3. Common additions:
4. Nozzle cleaning (_CLEAN_NOZZLE)
5. Bed mesh calibration (BED_MESH_CALIBRATE)
6. Prime lines or purge sequences
7. LED status indicators

Always ensure T0 is used for the final QGL and Z homing, as this is critical for accurate tool alignment.

For advanced features: See the Advanced PRINT_START Example which includes smart QGL selection and tool detection.