Camera alignment accuracy?

I have a Co2 laser with Rudia controller. I require 0.2mm accuracy for alignment of final cut in a project. Is a camera setup this accurate?

Currently I have cut lines on the material and in the final cut, I cut dotted lines over them. If the alignment is off I can stop or pause the job, move the material and start it back up. I would like to make this automated with a camera if possible, probably needs to be mounted to the laser head.

In a word: no.

You can get sub-millimeter accuracy on the average, but the transformations required to convert the camera view into the linearized camera field pretty much won’t produce consistent results across the entire platform.

The other gotcha is most consumer-grade printers aren’t calibrated to that degree, so the positions on the printed material don’t match the positions in the laser layout even though they’re both at the same nominal coordinates.

Laser printers definitely distort the paper while cooking the toner and inkjet printers aren’t particularly accurate in the vertical direction.

You may be able to use Print-and-Cut to get Good Enough™ alignment, although it will require careful attention to keeping the red-dot pointer aligned with the focused beam.

I’m not doing any printing. I am matching one laser cut to another one after removing the job, making modifications and re-inserting it for the next cut. I have seen some large sign lasers that look at little target icons and then align the drawing to the piece. Any camera setup would be at the laser head, not an overhead camera that looks at the entire cutting area.

Although LightBurn has a head-mounted camera option, it’s described as “still in beta” and rather lightly documented, so I think depending on it would require careful experimentation.

You could use Print-and-Cut to achieve the same goal without a camera, because it aligns the pattern to targets on the material. The targets can be part of the pattern, as long as you can match them to their corresponding positions on the material.

I looked into Print and Cut but there is no way that’s going to be 0.2mm accuracy. Looks like I’ll have to stick with the methods I’m using. I made a corner bracket to hold material and I can adjust the position of the bracket by twisting an off-set magnet. The problem is that sometimes I need to make multiple adjustments for whatever reason and the multiple test cuts make it too messy to know where the next test cut really ends up. I’m looking for ways to speed this up or make it easier.

Given that the CO₂ laser spot is around 0.2 mm diameter and a red dot pointer is much larger, that’s certainly true. I expect a head-mounted camera would be even worse, if only because of how hard it is to accurately measure the offset between the camera reticle and the laser spot, then maintain that accuracy in normal operation.

Out of an abundance of curiosity, I gotta ask: what are you cutting that requires such repeatable accuracy in a multi-step process?

I have a 3-step process where I cut two different sheets, combine them and then put it back in for a 3rd cut. I’m often doing small details and the 3rd cut may come within 0.5mm of the 1st or 2nd. So anything more than 0.2mm can cause problems.

Now, that’s finicky! :grin: