3D Printing: Multi-Axis with Klipper

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Updates:

  • 2025/06/05: publishing article
  • 2025/05/30: updating maf.cfg and more documentation
  • 2025/05/23: first write-up with MAF maf.cfg

Introduction

As of May 2025 Klipper supports multi-axis support on G-code level. It was possible to define “manual stepper“ motors, but those needed to be handled via “Extended G-code” of Klipper. Now those “manual steppers” can be tied to a G-code axis, and thereby multi-axis system can be composed and becomes available in traditional G-code context.

MANUAL_STEPPER STEPPER=stepper_x1 GCODE_AXIS=A

and after that 

G0 A100

can be used.

As of 2025/05 only G0/G1 is supported, but not G92, M82 (absolute extrusion), M83 (relative extrusion) in case “manual stepper” is used as additional extruder motors – so I coded a Multi-Axis Framework for Klipper, just a bunch of Klipper macros which provide a better multi-axis & multi-extruder support:

  • G0, G1 supports relative extrusion if enabled with M83 (I prefer)
  • G28 homing the new axes as well
  • G92 supports the new axes too
  • M82, M83 switches absolute/relative extrusion
  • T0, T1, … switch extruders
  • M104, M109 support of multiple extruders using T<n> notion

Klipper natively supports:

  • G90, G91 for new axes also

Setup

Create a dedicated file, or add following into printer.cfg, for example:

[include maf.cfg]

[gcode_macro MY_MAF]
variable_maf = {
      "X": { "motor": "stepper_x", "dir": -1, "end_pos": 0 },
      "Y": { "motor": "stepper_y", "dir": -1, "end_pos": 0 },
      "Z": { "motor": "stepper_z", "dir": -1, "end_pos": 0, "bounce": 2 },
      "E": { "motor": "extruder" },
      "U": { "motor": "stepper_x1", "dir": -1, "end_pos": 0 },
      "V": { "motor": "stepper_x2" "dir": 1, "end_pos": 380 },
      "W": { "motor": "stepper_x3" "dir": -1, "end_pos": 0 },
      "A": { "motor": "extruder1" },
      "B": { "motor": "extruder2" },
      "C": { "motor": "extruder3" }
   }
gcode:

This defines all axes, the additional 3 X carriages, and additional 3 extruders. If you declare X, Y, Z as well, it will home the same way as the new axes. By default after sensor is hit for homing, it bounces back 10mm (recommended for sensorless homing), you can override it with “bounce” value.

The maf.cfg once included, the MAF will be automatically executed at boot/restart.

M82 / M83: Absolute / Relative Extrusion

This applies to all extruders, M82 (absolute extrusion) is the default. I prefer relative extrusion (M83) as it makes it easier to insert or remove G-code without affecting existing G-code with extrusion.

G92: Set Position

Any new axis can be set now, including the extruders.

G92 W0 A0 B90 C110

M104 / M109: Set Temperatures

One can set temperature per extruder/tool:

T0
M104 S200
T1
M104 S200

or more compact

M104 T0 S200
M104 T1 S200

M104 set the temperature but doesn’t wait, and M109 waits until temperature is reached.

G28: Homing

The new axes can be homed as well:

G28 X Y U V W
G28 Z

Note: if you declared the axis in MY_MAF it will use the new G28 procedure, otherwise uses the native Klipper one.

G0 / G1: Move & Extrude

The G0 / G1 is overridden in order to support relative extrusion. 

M83                      ; relative extrusion
G0 X100 U300 Y100        ; move two X carriages on common Y gantry
G1 X150 U350 Y150 E5 W5  ; extrude with both extruders on the X carriages

Note: given we work in cartesian kinematics, X Y Z dictates the total distance as dist = sqrt (X^2+Y^2+Z^2) and the feedrate F (mm/min), any additional axis is given time t = dist (mm) / feedrate (mm/min) to reach its destination, and therefore has its own feedrate or speed – so, when operating new axes in this context, it’s up to you to be aware of the other axes speeds and keep them below operation limits.

MAF: Current State

One can send MAF command, and an output like this is received:

echo: == MAF: Multi-Axis Framework 0.1.0 ==
echo:  motion mode: absolute
echo: extrude mode: absolute
echo: axis X: stepper_x, pos: 0.0000
echo: axis Y: stepper_y, pos: 0.0000
echo: axis Z: stepper_z, pos: 0.0000
echo: axis E: extruder / T0, pos: 0.0000
echo:    temperature: 26.67C / 0.0C
echo: axis U: stepper_x1, pos: 0.0000
echo: axis A: stepper_x2, pos: 0.0000
echo: axis I: stepper_x3, pos: 0.0000
echo: axis B: stepper_y1, pos: 0.0000
echo: axis W: extruder1 / T1, pos: 0.0000
echo:    temperature: 26.82C / 0.0C
echo: axis C: extruder2 / T2, pos: 0.0000
echo:    temperature: 26.49C / 0.0C
echo: axis K: extruder3 / T3, pos: 0.0000
echo:    temperature: 26.57C / 0.0C
ok

Download

I plan to keep the code updated and backward compatible.

Use Case

I used “MAF” for early prototyping a Multi Gantry with Multi Extruder (IDEX) setup – Ashtar Q (MG2 IDEX) – printing in duplication mode (horizontal & vertical mirrored) on G-code level.

Ashtar Q (MG2 IDEX): 11 Axis Setup – early prototype
Ashtar Q (MG2 IDEX): 11 Axis Setup – early prototype
Ashtar Q (MG2 IDEX): 11 Axis Setup – early prototype

Operating in two different modes:

  • 1x Klipper instance (with 4x MCUs): 2x Y gantries, 4x X carriages, 4x extruders = 11 axis (XYZE+XE+XYE+XE) – all motors fully synced
  • 2x Klipper instances (with 2x MCUs each): Dual of 1x Y gantry, 2x X carriages, 2x extruders = 6 axis (XYZE+XE) + 5 axis (XYE+XE) – two gantries loosely synced

References