C3D allows LightBurn to move K40 but not fire laser

I have a K40 and when I downloaded Lightburn I was told by their support team that they either use a Ruida controller or a C3D controller. I purchased a C3D controller and replaced the M2Nano per the instructions. Simple enough.

I then go to set up the controller under the “Devices” tab and low and behold, C3D isn’t even listed as shown on Lightburn’s own website. Hmmm. Then when I go to set it up manually, I select GRBL 1.1f and the laser head homes. I can move it all around the table and even run the program I created in LB. However, no matter what setting I use, the laser never fires. 10%-100% it doesn’t matter what I set the line to.

I try to connect to the device using the edit>machine settings and I get a message that LB failed to communicate with the controller.

I have to say, this more than a little disappointing. I spent well over $200 on the controller YOU recommended, Installed it per the given instructions, Connect the USB (not the blue K40 USB) go to devices (No C3D as shown on LB website), install GRBL, and it doesn’t work…

The default firmware is Smoothieware for the C3D board. Give that a try in the devices setup.

“C3D” is the name of the board, but there are quite literally dozens of boards that run GRBL firmware, and it was tiring answering the “what board do I have?” questions, and more vendors and 3rd parties were asking to have theirs listed, and it was quickly becoming a user nightmare.

We removed all the “boards” and “machines” and now differentiate only by firmware for GCode systems.

Try this:

  • delete your device completely from the devices list in LightBurn and re-run the software. You’ll get the “create device” prompt you got before.

  • click “Cancel”, then “Find my Laser”

  • we’re in the process of getting new videos done, as well as changing the opening flow to make this the new default, as it’s much easier to use the auto-finder in most cases.

Thank you Anthony,

I tried using the smoothie option. When I select that, I don’t even get the “machine settings” option in the edit menu. I appreciate your help. I’m going to try and delete and find it as suggested by LB Oz.

I have attempted 3 times. Each time, shutting down LB completely and restarting. I even restarted my PC on this last one and each time I get the dreaded “LB is not responding” message.

Hi Robert,

Let’s take this one step at a time.

What operating system are you running?

You deleted all existing devices in LightBurn?

If Find My Laser isn’t working for you, that’s something we can look into, but for now let’s just go ahead and set up a fresh device manually, using Smoothieware as the device.

Now, once you have done that, you should not expect to see Machine Settings in the Edit menu for a Smoothieware device. That’s a different thing for different firmware. Don’t worry about it for now.

Hi Ray,

Thank you for the response. I am running Windows 10. I did delete all devices. After a 2nd restart of the computer and the third restart of LB it finally found it as a smoothiware device. It appears to be running fine but, as you mentioned, I have no option for machine controls. How do I now get it flipped over to GRBL?

Please clarify what you mean by this. A move panel exists here:


Use it as is with Smoothie, learn the ropes first, then when you are ready to try GRBL-LPC it is documented on the Cohesion3D Forum.

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