Ideas for cutting arched cardboard

Hello!!
I have purchased an AtomStack 30W laser to cut cardboard templates. This cardboard usually arrives in rolls so it is difficult to leave it completely flat, it tends to stay somewhat arched and in focus it becomes complicated, in addition to rubbing the head with the material. Does anyone have any ideas? I can’t use magnets because I can’t precisely adjust where to place them so that the laser doesn’t pass over them. any ideas?
I’ve thought about making a vacuum bed, basically a flat wooden box and making some fine holes all over the surface and putting an inlet for a vacuum cleaner, but I don’t know if it would work or if anyone knows of a simpler method.

Regards and thanks for all!!

I cut parchment paper to put under my loafs of bread for baking. The paper comes off the roll ‘curved’ and I can pull it over the edge of the counter and get it pretty flat.

To get the best, I use magnets to hold it down to the bed… I know that’s not an option with your setup…

Maybe a flat sheet of steel to put the laser on and you can place your magnets?

You can run the job at very low power and it would be like framing. You could watch where it went and place magnets accordingly…?

We all face this, even with mdf or other ‘natural’ materials…

Good luck

:smile_cat:

I actually used to cut a LOT of the on-roll single sided cardboard as protective layers for the large contract I had way back when. Ultimately the best solution was vacuum workholding.

Double face tape?

Thanks for all replies. Double face tape is not a solution. It can damage the material when peeling it off, it is expensive and also time consuming. I think I’ll have to try to make myself a vacuum workholding…

Thanks for all!!!

I usually place a couple of pieces of flat bar steel on top to keep it flat

I have similar issues with cutting some wood veneers that don’t lie flat. Normally I’ll just tape the veneer perimeter to a glass plate and do the cut. If the veneer has a bow, I’ll use the same perimeter taping (outside the cutting area) and place the veneers convex side down. This works well to keep everything flat.
With the ornery veneers I’ll use another glass plate over the top to weight it down. If really bad, I’ll hinge one edge of the glass to the lower plate with tape, The veneer is then placed in between, top glass hinged over and secured “shut” with another strip of tape or sometimes just a pair of those black spring metal office supply binder clamps.

Power/speed settings change a bit to prevent burning since the material can’t cool as well. I find doing more passes at lower power versus one at a higher power helps as well.

YMMV

You say you put a glass on top? Does the laser burn glass? I had thought something like that, but I assumed that the laser would burn the surface of the glass and leave it opaque in the areas where it passes. I can get fine glass. This machine, having a fixed focus, should be only 2mm from the surface to be cut, but I think I can get 1.5mm glass, this would be a great solution if the glass allows the material to be cut without being opaque

Regards

You have a diode laser right?

The glass will only etch if it has something to catch the beam (like being painted black) otherwise it passes right through.

You can set your focus point on the surface of the lower glass plate or the top of your material.
The top glass will get lightly etched on the surface where it rests against your material. When I do these glass sandwich cuts, I’ll clean the glass between sessions with some glass cleaner (Windex) and paper towels. The small amount of etching doesn’t affect the following cuts and I have reused my top sheet dozens of times.
Keeping your speed/power down so it cuts, but no more will keep the glass etching to a minimum.

I wasn’t aware your laser had such a small amount of clearance between the workpiece and lens. My focus point is maybe 3-4 cm from the lens.

“Single strength” glass is about 2mm so if your focus distance is that critical it’ll be a tight fit :smiley:

With top/bottom glass cutting veneer:
IMG_8300

Single bottom layer of glass with veneer attached with tape around perimeter:
IMG_8301 (1)

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Yes, the distance is really small, hence it has problems with convex material, it must be a very flat material to maintain a clean cut and that the head does not rub. I would have preferred to have more distance, but it was something that I did not know when I bought the machine and that I am learning now :frowning:

Regards!