Camera alignment and cut height question

I know I keep asking the dumbest questions, but here’s another. I mounted a camera on the housing for my longer B1 laser. I followed all of the calibration and alignment steps using an old piece of 5 mm plywood placed on the bed of my machine. Everything worked smoothly and I could accurately outline test objects in any position on the bed. However, I realized that when I put my honeycomb onto the bed when I want to cut through material, it raised the base height by ~ 0.75 inch and throws off the camera calibration. As I understand it, the work piece is now nearer to the camera it so takes up proportionately more of the optical space of the camera chip and therefore seems “bigger” to the software than it would if it were on the bed of the laser.
I know the obvious answer would be to align the camera to the height of the honeycomb but I often work with relatively “thick” and wide pieces that do not fit under the Y axis arms with the honeycomb in place. Is there a way to save a alignment file(s) to a folder that I could call upon as/.when needed? That way I could have an alignment file for objects on the bed, and another for objects on the honeycomb table.
To illustrate the problem. I was trying to do some intricate cutting on a rectangular piece of plywood on my honeycomb and when I used the set laser position toggle to move the laser to the edge of the wood the resulting laser position was always off by ~ 2 - 3 mm. I outlined the wood with a rectangle in the software and ran an engraving pathway. It was off in both the x and Y axis. I could adjust using the camera x and y shift but that seemed like fudging it.
I thought I had knocked the camera out of alignment and maybe needed to realign it. However, when I used the camera to view the piece of wood on the bed of the laser and brought up the rectangular outline that I had made of it on the honeycomb, the outline was bigger than the wood in both x and Y axis by about 7 mm. Just to make sure, i made a new rectangular outline with this camera view and resulting engraving was spot on!
Any ideas as to how to easily get round this issue would be greatly appreciated.

Right click on the Camera Control window and do Export Camera Settings. You can similarly import on the same screen.

Note that I’ve seen LightBurn be a little finicky when making many such changes continuously. You may want to restart LightBurn between changes.

As an alternative, if camera alignment across material heights is important then consider a mechanism that allows you to change machine+camera height such that distance from camera to material remains the same in spite of material height differences.

If the camera is rigidly mounted to the frame of your laser then you could accomplish this with shims underneath the feet of the laser. Something mechanical or automated would be even better.

Great, thanks again for the input. I hoped that there would be a way to save the files

BTW, do i have to recalibrate the camera as well for the different level or just run the alignment again?

I assume you’re asking about the lens here. No, you should only need to do the camera alignment at each discrete height.

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.