Homing (G28) override for Klipper [v.3]

This macro overrides klipper ( https://github.com/KevinOConnor/klipper ) homing process to make a better customisation and

Dependencies

Requires having this somewhere in your printer configuration for SET_KINEMATIC_POSITION to work

[force_move]
enable_force_move: true

How to install

1. download file through any method (file download, git clone, etc) to the computer running klipper
2. add to configuration ( https://github.com/KevinOConnor/klipper/blob/master/docs/Config_Reference.md#include )

[include path/to/folder/macro_g28_override.cfg]

3. also add to configuration if respond is not already configured ( https://github.com/KevinOConnor/klipper/blob/master/docs/Config_Reference.md#respond )

[respond]

and

[force_move]
enable_force_move: true

4. configure homing as described below

Example File

[include macro_g28.cfg]

[gcode_macro HOMING_CONFIG]
variable_order: "x,y,z"
variable_dowith_z: "x,y"
variable_start_zhop: 20
gcode:
  RESPOND PREFIX="info" MSG="Homing config..."

[gcode_macro HOMING_OVERRIDE_BEFORE]
gcode:
    RESPOND PREFIX="info" MSG="Homing > Before homing: {params.X} - {params.Y} - {params.Z}"

[gcode_macro HOMING_OVERRIDE_X]
gcode:
    RESPOND PREFIX="info" MSG="Homing > X"
    G90
    G990028 X0
    G91
    G0 X-5 F2000
    G90

  
[gcode_macro HOMING_OVERRIDE_Y]
gcode:
    RESPOND PREFIX="info" MSG="Home > Y"
    G90
    G990028 Y0
    G91
    G0 Y-5 F2000
    G90

[gcode_macro HOMING_OVERRIDE_Z]
gcode:
    RESPOND PREFIX="info" MSG="Homing > Z"
    G90
    G0 X220 Y220
    G990028 Z0
    G91
    G0 Z30
    G90

[gcode_macro HOMING_OVERRIDE_AFTER]
gcode:
    RESPOND PREFIX="info" MSG="Homing > After homing: {params.X} - {params.Y} - {params.Z}"

Configuration

You need to add some configuration for these macros to be useful For example the configuration below has

• order of homing: X then Y then Z
• X and Y can be homed independently
• Z requires both X and Y to be homed (and because of order settings, if you home only Z then X Y and Z will be homed in this specific order)

[gcode_macro HOMING_CONFIG]
variable_order: "y,x,z"
variable_dowith_z: "x,y"
variable_start_zhop: 20
gcode:
  RESPOND PREFIX="info" MSG="Homing config"

Read below for description of settings

Features

Keep track of actual homing status and can allow homing of each axis only when needed

When zero value is specified axis will not be homed if already "real" homed G28 X0 - will home only if needed G28 X - will always home X, regardless of status

Home Ordering

By editing adding the following configuration in your printer config file you can change the default homing order

[gcode_macro HOMING_OVERRIDE_CONFIG]
variable_order: "x,y,z"
gcode:
  RESPOND PREFIX="info" MSG="Homing config"

Just edit the "x,y,z" and put any order you want in it. Make sure all axis you want to home are set there, since if you skip one it will not be homed. Use lowercase letters for all axies.

Homing Dependencies

Sometimes homing an axis requires another one to be also homed, for example you want to home Y before X every time. In this case G28 X should home Y then X. This is resolved by setting homing order (see above) to "y,x,z" then set Y as a dependency of x by adding this to your config file

[gcode_macro HOMING_OVERRIDE_CONFIG]
variable_dowith_x: "y"
gcode:
  RESPOND PREFIX="info" MSG="Homing config"

If you don't want/need a dependency for an axis, just comment or remove that line

Homing Z-hop start

If you want to start homing by lifting the printhead (relative to bed), you can use this setting

[gcode_macro HOMING_OVERRIDE_CONFIG]
variable_start_zhop: 20
gcode:
  RESPOND PREFIX="info" MSG="Homing config"

Overriding individual axis homing

For each axis you can create a macro named "HOMING_OVERRIDE_<axis_name>" like below. Each gcode must contain G990028 X0 gcode command - replace X with the axis you're overriding

[gcode_macro HOMING_OVERRIDE_X]
gcode:
  RESPOND PREFIX="info" MSG="Homing > X"
  G90
  G990028 X0
  G91
  G0 X5 F2000
  G90
  
[gcode_macro HOMING_OVERRIDE_Y]
gcode:
  RESPOND PREFIX="info" MSG="Home > Y"
  G90
  G990028 Y0
  G91
  G0 Y-5 F2000
  G90
  
[gcode_macro HOMING_OVERRIDE_Z]
gcode:
  RESPOND PREFIX="info" MSG="Homing > Z"
  G90
  G0 X100 Y100
  G990028 Z0
  G91
  G0 Z20
  G90

You can override only the axis you need.

Overriding initial Z hop

[gcode_macro HOMING_OVERRIDE_ZHOP]
gcode:
  RESPOND PREFIX="info" MSG="Homing > Z Hop"
  SET_KINEMATIC_POSITION Z=0
  G91
  G0 Z{printer['gcode_macro HOMING_CONFIG'].start_zhop|int}
  G90

Run gcode before and after homing

These macros are called with paremeters X=1 Y=1 Z=1 where value is 1 for the axis that will be/were homed

[gcode_macro HOMING_OVERRIDE_BEFORE]
gcode:
  RESPOND PREFIX="info" MSG="Homing > Before G-code"
  

[gcode_macro HOMING_OVERRIDE_AFTER]
gcode:
  RESPOND PREFIX="info" MSG="Homing > After G-code"