Larger Laser Machine Installation Guide

Larger Laser Machine Installation Guide

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If you have a larger laser machine, follow this guide for tips on how to get running smoothly. Please read this article in its entirety, as there are many aspects covered to get your machine setup.

For an overview of what to expect when installing the Cohesion3D LaserBoard into your machine, we highly recommend watching this Larger K40 Upgrade Guide by Teaching Tech. It is a great resource for getting started.

Identify your controller and take a good picture of the stock electronics prior to making changes, in case you need to backtrack later. 

For more information, review the Laser Power Supply Connection Guide for common connections. Some of the following terms may be used interchangeably when referring to connections and terminals, depending on how your board is marked:

Term Alternate  
Gnd G, GND, Ground  
L TL, LO, Laser  


M2Nano Board

Identify your variant of board and wiring configuration in the Cohesion3D LaserBoard Installation Guide, then follow the instructions for replacement. Check the Compatibility tab on the LaserBoard product page for more variations.  Below is a common example of the M2Nano:

M2Nano Board

In some instances, the M2Nano will be wired using the two pin connector in the upper right corner and have some wires also connected to the 4 pin power connector in the lower right corner. This variant is compatible, but will require some rewiring similar to the 6-pin version.

If your wiring looks different than the installation guide or you have a 6-pin version, continue reading below. See Installing Drivers section as well.

B1/M1/Moshi Boards

4 Pin Variant

For the B1/M1/Moshi controller variants, the board will be larger than the standard M2Nano, so some mount modifications and/or new holes may be necessary to install the LaserBoard. Use M4 Hex Standoffs on the panel and M4 screws to secure the board. If desired, refer to the Teaching Tech video above for ideas about alternative mounting solutions.

6 Pin Variant

If you have a 6 pin variant of the power connector, refer to the instructions for this setup, along with the Cohesion3D LaserBoard Installation Guide.

See Installing Drivers section below.

If your board is not covered here, or the wiring looks different, please take pictures of your machine, control panel, board, other electrical components, and wiring. Contact us on our Support Forum for assistance.

Stepper Motors

If your machine has larger dimensions (greater than 300 mm x 200 mm) or uses stepper motors which are larger than Nema 17, review our Cohesion3D LaserBoard Buyers Guide for recommendations on external stepper drivers, the stepper driver cable pack and Cohesion3D 24V 4A DC Power Supply. Also see the relevant documentation for Connecting External Stepper Drivers to your LaserBoard.


For larger machines, the bed size measurement will exceed the standard working area, so follow the steps for Setting Up the Correct Bed Size.

IMPORTANT: Review the documentation for Setting Up the Origin. Also, watch the Machine and Job Origin video for reference.

In LightBurn, on the Laser panel, choose “Devices”. Create or edit your Device. Enter the relevant information or click “Next” until you get to the origin screen prompt. Disable auto homing in the device configuration.


Home the machine, then use jog commands to move the head around to ensure it traverses properly. Measure the movement intervals to determine the exact amount of travel distance that you have/want and make note of the values in millimeters to input into the configuration file and LightBurn Device Settings.

If your machine homes to a different location than rear left, is jogging in the opposite direction, the laser head is crashing or making odd movements, there are some configuration changes to consider to correct it.

Installing Drivers

Determine if you need to install drivers: Smoothie Drivers

Updating the Config File

The below configuration parameters may need to be altered to dial in the settings for your machine. Values provided are starting points which should be tweaked to optimize your machine performance:

    1. Power off the C3D Board and remove the memory card. No lights should be on.
    2. Put the board’s memory card into your computer, using a MicroSD / SD reader if necessary.
    3. Open the config.txt on the memory card using an editor such as Sublime Text. Do not use Notepad++.
    4. Decrease the feed rate (Ex: 2000 down to 1000 to test)

      default_feed_rate 2000 # Default rate ( mm/minute ) for G1/G2/G3 moves

    5. Decrease the seek rate to slow travel movement (not cuts), testing lower values incrementally until fine tuned (Ex: 12000, 9000, 6000)

      default_seek_rate 12000 # Default rate ( mm/minute ) for G0 moves

    6. Decrease global acceleration to slow moves between cuts (Ex: 2000 down to 1000 to test)

      acceleration 1000 # Acceleration in mm/second/second.

    7. Decrease max speeds, testing lower values incrementally until fine tuned (Ex: 12000, 9000, 6000)

      x_axis_max_speed 12000 # mm/min
      y_axis_max_speed 12000 # mm/min

    8. Check the specifications on your stepper motors and increase current levels to dial in internal stepper drivers (not required for external drivers). See: Changing Stepper Motor Currents

      alpha_current 0.4 # X stepper motor current
      beta_current 0.6 # Y stepper motor current

    9. Update alpha and beta max to define your bed size:

      alpha_max – update based on the previously measured travel amount on the X axis
      beta_max – update based on the previously measured travel amount on the Y axis

      Note: The alpha and beta max dimensions entered on the config file will display in the prompt when setting up the laser using the LightBurn Device Wizard.

    10. Update the alpha_max_travel and beta_max_travel (Also see: Crashing into Gantry)
    11. Decrease the fast homing values, until fine tuned (Ex: 100 down to 50 to test)

      alpha_fast_homing_rate_mm_s adjusts the speed in millimeters/second (X axis)
      beta_fast_homing_rate_mm_s adjusts the speed in millimeters/second (Y axis)

      Similarly, if you have a motorized Z-table, the gamma values for the relevant parameters listed above can also be altered to dial in the configuration along the Z axis.

    12. Save the config.txt file on the memory card.
    13. “Safely Eject” or “Unmount” the memory card.
    14. Put the memory card back into the board and power up.

If you are still experiencing issues after making these configuration changes, you may be dealing with corrupt files. Reflash the SD card with fresh Cohesion3D LaserBoard firmware, make the necessary config file changes again, and resume testing.