GRBL-LPC for Cohesion3D LaserBoard


The Cohesion3D LaserBoard ships with Smoothie firmware which is a good general purpose firmware, is great for vector cutting, supports a GLCD Screen and can be edited via the memory card’s config.txt file.
However it can only raster engrave images up to a certain speed.
If you try to engrave grayscale image with 0.1mm dot size (254 dpi) at 100mm/s or higher and you start to see sections shifting, you are exceeding the throughput limits.
You can mitigate by using the newsprint dither mode in LightBurn instead of grayscale.

Alternatively, you can try to use the GRBL-LPC firmware. Just copy the SpreadCycle file linked right below - you’ll need to rename it to firmware.bin (be mindful of your file extensions) and then put it on the board’s memory card. Then place the card into the board and turn the board power on. You should see the LEDs count up for a moment, then only one LED should be on.

You’ll need to set up a new device in LightBurn with the Cohesion3D (GRBL) controller option, and off you go.

Note that GRBL-LPC does not support the GLCD Screen - that’s the current trade off as explained on our LaserBoard product page.

SpreadCycle version: firmware_grbl-lpc_c3dlaserboard_4axis_spreadcycle.bin

StealthChop version: firmware_grbl-lpc_c3dlaserboard_4axis_stealthchop.bin

GRBL-LPC Driver: usbser.inf

With the SpreadCycle mode, you may hear a hissing sound when the motors are energized and standing still. This is not a fault of the stepper drivers, but a result of high inductance motors used in the machine. You can try the StealthChop firmware version which should result in almost entirely silent motors.

NOTE: Apparently the first link for the SpreadCycle version actually was pointing to the StealthChop version. So the 21 people that downloaded it and are experiencing silent motors as a result, enjoy :slight_smile:. Download links are now corrected as of 2/27/19.

We thank @Jfong for compiling GRBL-LPC for us, you can find more information on his site here:

Cohesion3D usb dropout
Problems with C3D with LightBurn
USB Dropouts and Brownouts