K40 with new LaserBoard going nuts

Machine: k40 that came with nano

Board: Cohesion3d

Firmware: smoothie that came with the board

Problem/ Question: Newly installed LaserBoard cut and engraved great for first 2 projects and went completely crazy. Machine now tries to cut out of range XY axis and when cutting the same project in the same spot on Lightburn will randomly move. I have attached a video, yes the bed size has been set on Lightburn and with the code on the SD card


Side note, laser works perfectly with old nano board installed using k40 whisper.

When commanded via lightburn to a certain spot on the workspace with the location tool machine works perfectly. This only happens when trying to cut or engrave.

Hi Zach,

Welcome to the forum! I have upgraded your trust level so that you can now upload pictures.

Please provide photos of your machine, control panel, board, other electrical components, and wiring. The link to the video you shared is private. Can you update it, please?

I have changed the video to public sorry for the inconvenience. photos do not want to upload as I’m sure it has something todo with the fact I’m using a Mac

Thanks, Zach.

First, check that your origin is set properly in LightBurn and that the bed sizes match in Edit > Device Settings.

For more information: Set Origin

bed sizes match what was programmed to the SD card, origin was set to front left as shown and no change.

Hi Zach,

Please try to upload pictures of your machine, control panel, board, other electrical components, and wiring. We need to see close up images of everything in order to do full diagnostics.

Perform the following tests and report back with the results for each:

  • With the power off, move the laser head to the middle of the bed and then power on.
  • In LightBurn, on the “Move” tab, test the jogging using the arrow buttons to confirm:
    • Left arrow moves left
    • Right arrow moves right
    • Up arrow moves toward the back of the machine
    • Down arrow moves toward the front of the machine
  • In LightBurn, on the “Laser” tab, test the “Home” button to see if the machine homes to the location where your limit switches / endstops are located or triggered.

I did all the steps you asked for, when hitting the home button the machine will home but you can actually hear the machine trying to travel and will continue until the stop button is pressed.

[3-C27-AA4-A-20-DB-4-DE5-B2-AD-34-D1-B86-E7-F09 EB64-E2-EA-AD34-420-D-B4-D2-6698-CAAAE2-B9 343-A4-A0-C-8-F65-4059-AE3-B-5-D2-E0-FF6-D74-C 4-D7-E5-B70-1-C42-48-DE-9-FE1-745-B836-E378-D 2-C630-B78-FAF1-4-A8-A-AA24-1-F590289-E6-AD](3-C27-AA4-A-20-DB-4-DE5-B2-AD-34-D1-B86-E7-F09 EB64-E2-EA-AD34-420-D-B4-D2-6698-CAAAE2-B9 343-A4-A0-C-8-F65-4059-AE3-B-5-D2-E0-FF6-D74-C 4-D7-E5-B70-1-C42-48-DE-9-FE1-745-B836-E378-D 2-C630-B78-FAF1-4-A8-A-AA24-1-F590289-E6-AD)

Thanks for the photos!

Please confirm - when you hit the arrows, they move in the expected directions previously mentioned?

Check your configuration file to see if you need to adjust any parameters: Laser Head Crashing into Gantry

If you need help with this part, let me know and I can update it with you.

when hitting the arrows it moves where commanded, when using the location tool it moves when commanded. I think your missing the entire issue here, only when trying to preform a cut/ engrave on the right side of the workspace does it try crashing into the left side. The K40 looses its mind and never cuts the same square in the same spot. this occurred after the first job was completed. I actually think something went wrong with the 3d controller.


another clip of the issue I’m having in detail and showing how I can command it to move where I want to. this only occurs when cutting.

I’ve been working with this thing all day long, even trying it on a windows pc. I am convinced their is something wrong with the cohesion3d board itself that must have went wrong after the first job had completed. I’ve tried every setting and I’m getting really tired. At this point I would really like to have a replacement sent out to verify.

oz from the LightBurn forum figured it out, looks like my current values required some attention out of the norm. Machine is working atm. Thanks for all your help