This page contains common gcode commands and example starting and ending scripts for LayerFused Printers. Also note that these commands are for Marlin Firmware. To send G-code commands to your printer you will need a terminal interface. There are many options to do this and even some Slicer applications do this. Pronterface and Octoprint are good ones to use.
G0 - G1 - Linear Move
Description: Add a linear move to the queue after all previous moves are completed. This type of move traces a straight line from point A to point B ensuring that all specified axes arrive at the same time.
Usage: G0 [E<pos>] [F<rate>] [X<pos>] [Y<pos>] [Z<pos>]
Example: G0 F3000 Z25 ; Move Z to 25mm with feedrate of 3000mm/m
G28 - Auto Home
Description: Home one or more axes.
Usage: G28 [X] [Y] [Z]
Example: G28 XY ; Home X and Y axes
G90 - Absolute Positioning
Description: All coordinates given in G-code are interpreted as positions in the logical coordinate space. This is the default for Marlin.
Usage: G90
Example: G90 ; Set all axes to absolute
G91 - Relative Positioning
Description: All coordinates are interpreted as relative to last position.
Usage: G91
Example: G91 ; Set all axes to relative
M92 - Set Axis Steps-per-unit
Description: This command sets steps-per-unit for one or more axes.
Usage: M92 [E<steps>] [X<steps] [Y<steps>] [Z<steps>]
Example: M92 Z800 ; sets the steps-per-unit on the Z axes to 800
M500 - Save Settings
Description: Save all configurable settings to EEPROM
Usage: M500
Example: M500
M501 - Restore Settings
Description: Loads all saved settings from EEPROM
Usage: M501
Example: M501
M502 - Factory Reset
Description: Restores the configurable settings to factory defaults.
Usage: M502
Example: M502 ; reset!
M503 - Report Settings
Description: Displays a report of the current EEPROM settings.
Usage: M503
Example: M503
M504 - Validate EEPROM Contents
Description: Validates contents of the EEPROM. If error "Initialize EEPROM Failed" use this.
Usage: M504
Example: M504
M914 - TMC Bump Sensitivity
Description: Some TMC stepper drivers can detect when they bump into something. This is used for Sensorless Homing. The TMC 2209 has this feature and emulates traditional EndStops.
Compatible with TMC2130 and TMC2209.
TMC2209: Sensitivity 0-255
Others: Sensitivity +63 to -64
Usage: M914 [X<int>] [Y<int>] [Z<int>]
Example: M914 X45 Y36 ; set sensitivity for X axi to 45 and Y axis to 36
M104 - Set Hotend Tempature
Description: Set the hotend tempature to desired temp.
Usage: M104 [S<temp>]
Example: M104 S210 ; Set active hotend to 210 degrees
M114 - Get Current Position
Description: Display current position of the active nozzle.
Usage: M114
Example: M114
M119 - Endstop States
Description: Display the current status of the endstops. "TRIGGERED" or "OPEN"
Usage: M119
Example: > M119
Reporting endstop status
x_min: open
y_min: open
z_min: TRIGGERED
M140 - Set Bed Tempature
Description: Set the bed tempature to desired temp.
Usage: M140 [S<temp>]
Example: M140 S70 ; Set the bed tempature to 70 degrees
There are many different variations of starting and ending scripts. What these scripts do depends on what you want to happen before you start a print and after your print is done.
G28 ; Home all axis
G1 Z10 F3000 ; Move Z down 10mm
; Prime the Extruder
G92 E0 ; Reset Extruder to 0
G1 F200 E3 ; Extrude 3mm of plastic
G92 E0 ; Reset Extruder to 0 again
M117 Printing... ; Display printing message on LCD
This script will home the printer then move the Z axis 10mm and prime the extruder before starting the print. There are a number of different processes that you can perform before starting such as implementing a nozzle wipe to ensure the flow of plastic is sufficent. If your machine is equipped with a leveling sensor you could issue a G29 to probe the bed and make sure that it is level. With M117 you can display whatever message you would like on the LCD.
One of the most important things that you should do with the end G-Code is ensure that you turn off the power to the Hotend and Bed heaters. Not only is this for safety but also good practice so you do not burn up any parts. One of the other benefits is you are able to either lower the build plate or push it forward for easy part removal.
M104 S0 ; Turn off the Hotend
M140 S0 ; Turn off the Heat Bed
; Retract the Filament
G92 E1 ; Set extruder position to 1
G1 E-1 F3000 ; Retract filament by 2
M211 S1 ; Make sure Soft Endstops are turned on
G91 ; Set relative position for all axes
G0 Z10 F3000 ; Move the Z axis 10mm from current location
G90 ; Set Absolute position for all axis
G0 X300 Y300 F3000 ; Move the X and Y axis out of the way
G0 Z250 ; Move the Z axis to 250mm for easy removal
M150 U255 ; Light up Green after complete