Hey Lightburn community,
I’m running into a very weird issue with my setup.
I just bought an 85 Degree 8MP LightBurn Camera with mount for my EMP ST60J MOPA Galvo Laser. I have it stuck to my laser using the 3D printed holder just below the cylinder that connects the head to the body. It is pointed down at the work bed. I have run the lens correction wizard multiple times. The part that I cant figure out is the very first image capture. When I place the pattern in the middle of the workspace and I click capture, the image comes back with one of two scores. 0.0 or an incredibly high number. It also does not show the image that was captured at all on either option. I can move onto the next pattern position and the capture function works how I would expect and I get scores around .3 to .5. I am concerned that this first capture is throwing the whole calibration off.
I have tried going the full way through and doing the cross hairs on the test pattern and have gotten the camera overlay to work, but I cant seem to get the camera to accurately represent what actually on my work bed. For example, I am marking a metal plate with connector holes in it. I pull in a DXF file that is dimensionally the same as the part being marked. When I turn on the camera, the DXF file and the image are not even close in terms of measurements. Maybe this is from the weirdness of that first capture step?
Please first make sure that your Galvo is engraving dimensionally accurate by engraving a rectangle of 100x100mm and measure the result.
This should be spot on already if you loaded a .COR file from the manufacturer. The Scale of the lens can be calibrated by clicking on these three dots in the Device Settings:
Are you using the new AprilTags calibration card? I like to print my card A5 size (scale it 50% in the print settings)
It is not necessary to mount the camera in the machine to perform the lens calibration. This process depends only on the camera’s lens, not its placement in your machine — as long as the camera and calibration pattern are perfectly still, calibration can be performed anywhere.
This may help with the placement to make sure it covers 1/9th of your camera view with each capture.
Hey @Aaron.F,
Thank you for your reply.
I have indeed calibrated and corrected the Galvo lens.
My lens is a 290 and is supposed to be able to cover a 200mm x 200mm area.
I have it dialed so that a 175mm square is exactly 175mm. So I know that the laser is cutting/marking dimensionally correct.
I was using the dots calibration, I can certainly try the AprilTags route and see if this helps. When I used the dots I did scale it down to 50%.
I will keep that in mind. I may remove the camera from the laser in order to do the lens correction and then put it back after correction is complete.
I’ll report back once I’ve tried these things.
