FDM/FFF GCodes

This file contains Machinekit FDM related GCodes and MCodes. These codes can be implemented using remaps. For an example how to integrate it take look at link: remap.ini.

GCodes

G22: Retract Extruder

Retracts the currently active extruder.

G23: Unretract Extruder

Unetracts the currently active extruder.

G28: Move to Origin

Example: G28

This code exists for compatibility reasons with RepRap flavor GCode. Machinekit does not support homing from GCode as homing needs to be triggered from the user interface. This code causes the FDM machine to move back to its X, Y and Z zero coordinates and resets the extruder axis.

If you add coordinates, then just the axes with coordinates specified will be zeroed. Thus G28 X0 Y72.3 will zero the X and Y axes, but not Z. The actual coordinate values are ignored.

G29: Detailed Z-Probe

Example: G29

Probes the bed at a specified number of point points (usually 3-4).

G29.1: Set Z probe head offset

Example: G29.1 X30 Y20 Z0.5

Set the offset of the Z probe head. The offset will be subtracted from all probe moves.

G29.2: Set Z probe head offset

calculated from toolhead position

Example: G29.2 Z0.0

Set the offset of the Z probe head. The offset will be subtracted from all probe moves. The calculated value is derived from the distance of the toolhead from the current axis zero point.

The user would typically place the toolhead at the zero point of the axis and issue the G29.2 command.

G30: Single Z Probe

Example: G30 X10 Y0

In its simplest form probes bed at current XY location.

If X, or Y values are specified (e.g. G30 X20 Y50) then those values are used instead of the machine’s current coordinates. The combination of these options allows for the machine to be moved to points using G1 commands, and then probe the bed, or for the user to position the nozzle interactively and use those coordinates. The user can also record those values and place them in a setup GCode file for automatic execution.

MCodes

Machinekit supports a number of FDM specific MCodes inspired by the RepRap MCodes. These codes are implemented using remapping. If you are interested in developing your own Machinekit based 3D printer take a look at the remap file.

M104: Set Extruder Temperature

Example: M104 P190

Set the temperature of the current extruder to 190 °C and return control to the host immediately (i.e. before that temperature has been reached by the extruder).

Multiple Exruders

M104 can be additionally used to handle all devices using a temperature sensor. It supports the additional T parameter, which is a zero-based index into the list of sensors. For devices without a temp sensor, see M106.

Example: M104 T1 P100

Set the temperature of the device attached to the second temperature sensor to 100 °C.

M106: Fan On

Example: M106 P127

Turn on the cooling fan at half speed.

Mandatory parameter 'S' declares the PWM value (0-255). M106 S0 turns the fan off.

M107: Fan Off

Example: M107

Turn on the cooling fan off.

Deprecated. Use M106 P0 instead. (But used by Slic3r)

Additional Fans/Devices

Additionally to the above, Machinekit uses M106 to control general devices. It supports the additional T parameter, which is an zero-based index into the list of fans/devices.

Example: M106 T2 P255

Turn on device #3 at full speed/wattage.

Sync with Motion

By default the M106 command will be executed with the next movement. This default behavior is used since the fan speed is constantly switched during execution and an unsynchronized movement would break look-ahead and path blending. For the purpose of executing a command immediately the M106 supports the additional I parameter.

Example: M106 I1 P127

Turn on the cooling fan at half speed immediately. I0 equals to not immediate, all other values evaluate to immediate if I is specified.

M109: Set Extruder Temperature and Wait

Example: M109 P185

Set extruder heater temperature in degrees celsius and wait for this temperature to be achieved.

Multiple Exruders

Similar to M104 this command supports the additional T parameter for specifying the extruder.

Example: M109 T1 P100

Set the temperature of the device attached to the second temperature sensor to 100 °C and wait for the temperature to be reached.

M140: Bed Temperature (Fast)

Example: M140 P55

Set the temperature of the build bed to 55 °C and return control to the host immediately (i.e. before that temperature has been reached by the bed).

M141: Chamber Temperature (Fast)

Example: M141 P30

Set the temperature of the chamber to 30 °C and return control to the host immediately (i.e. before that temperature has been reached by the chamber).

M190: Wait for bed temperature to reach

target temp

Example: M190 P60

Set the temperature of the build bed to 60 °C and wait for the temperature to be reached.

M191: Wait for chamber temperature to

reach target temp

Example: M191 P60

Set the temperature of the build chamber to 60 °C and wait for the temperature to be reached.

M200: Set filament diameter

Example: M200 D1.75

M200 Dm.mmm sets the filament diameter to m.mmm millimeters. It is used with 'volumetric calibration' and G-code generated for an ideal 1.128mm diameter filament, which has a volume of 1mm\^3 per millimeter. The intention is to be able to generate filament-independent g-code.

M207: Set retract parameters

Example M207 P0.5 Q10.0

Sets retract length P in mm and retract velocity Q in mm/s.

M221: Set extrusion scale

Example: M221 P0.96 sets the extrusion scale factor to 96%

Sets the scale factor that will be applied on the extrusion in percent of the standard extrusion output.

M226: Gcode Initiated Pause

Example: M226

Initiates a pause in the same way as if the pause button is pressed. That is, program execution is stopped and the printer waits for user interaction. This matches the behaviour of M1 in the NIST RS274NGC G-code standard.

M280: Set servo position

Example: M280 T0 P1500

Set servo position absolute. T: servo index, P: angle or microseconds

M300: Play beep sound

Usage: M300 Q<frequency Hz> P<duration ms>

Example: M300 Q300 P1000

Play beep sound, use to notify important events like the end of printing. The P parameter is optional and may not be supported by all electronics that implement the buzzer.

M400: Wait for current moves to finish

Example: M400

Finishes all current moves and and thus clears the buffer. That’s identical to G4 P0.

M420: Set RGBW Colors as PWM

Usage: M420 T<LED index (0-2)> R<Red PWM (0-1)> E<Green PWM (0-1)> D<Blue PWM (0-1)> P<White PWM (0-1)>

Example: M420 R1.0 E1.0 D1.0 P1.0

Set the color of your RGBW LEDs that are connected to PWM-enabled pins. Note, the Green color is controlled by the E value instead of the G value due to the G code being a primary code that cannot be overridden. The optional T parameter specifies the index of the LEDs to set (default 0).

M700: Set line cross section

Example: M700 P0.061

Sets the cross section for a line to extrude in velocity extrusion mode. When the extruder is enabled and movement is executed the amount of extruded filament will be calculated to match the specified line cross section.

M701: Set line width

Example: M701 P0.2

Sets the width of a line to extrude in velocity extrusion mode. The value will be used in combination with the line height to calculate the line cross section.

M702: Set line height

Example: M702 P0.15

Sets the height of a line to extrude in velocity extrusion mode. The value will be used in combination with the line height to calculate the line cross section.

M710: Jog filament

Usage: M710 P<length in mm> Q<velocity in mm/s> E<continuous 0 or 1>

Example: M710 P10.0 Q2.0 extrude 10mm of filament with a velocity of 2mm/s M710 Q4.0 E1 start continuous extrusion with a velocity of 4mm/s

Extrudes a certain amount of filament with the specified extrusion velocity. Extrusion velocity can be either positive or negative. The continuous parameter starts or stops continuously extruding filament with a specified velocity.

RepRap Alternatives

Some RepRap GCodes can not be implemented but easily replaced by native Machinekit GCodes.

M206: Set home offset

Replacement: G10 L2 P1 X10.0 Y10.0 Z-0.4

The values specified are added to the endstop position when the axes are referenced. The same can be achieved with a G92 right after homing (G28, G161).

M306: Set home offset calculated from toolhead position

Replacement: G10 L20 P1 X10.0 Y10.0 Z-0.4

The values specified are added to the calculated end stop position when the axes are referenced. The calculated value is derived from the distance of the toolhead from the current axis zero point.

The user would typically place the toolhead at the zero point of the axis and issue the M306 command.