Setting the power too low?

Is there any negative to setting the lasers power too low for a material? I mean, of course it won’t cut/engrave if the power level isn’t high enough, but anything else?

For example, i’ve been messing with cardboard, and noticed a distinct burnt cardboard smell and have been adjusting power/speed to minimize it. I noticed the lower power seems to smell worse and makes me wonder if perhaps its actually burning rather than vaporizing?

Could just be placebo though.


i mean, yes, it’s burning your cardboard. it’s dumping a lot of energy into whatever you’re cutting, and not all of that goes to ablating away the surface.

but to answer your question, no, there’s no harm you can do by setting your glowforge to its minimum power setting; in fact, they’re going to roll out an improved low-power setting someday, which will go much lower than your current minimum setting.

the other thing to consider is that you can speed the laser up, which automatically means less energy is transferred to your material, and is less likely to cause burning issues.

It’s a good point. Do a bunch of test squares at different powers and speeds. Take the resulting squares and rub an edge onto a piece of white paper. See how much carbon is transfered. Then you can get a better sense of the power/speed ratio. My tube is 40/60. That is a balance between side charring and kerf width and making it all the way through a .15" piece of corrugated cardboard. Lots of variables to consider.


I’ve been cutting my Amazon boxes at 50/50. No smell that I was able to notice and it cut surprisingly cleanly. I cut some thin cork earlier at 40/100. Took me a few tries to dial that one in. I spent hours last night testing some wood engraves. Bottom line? Try things out and see what you get.

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I was using your speed as a baseline, though there are so many types of cardboard… I’ve gone as low as 20/60 and cut through, though as I said, I feel like it’s actually leaving more of a burnt edge than the higher setting. Though it’s quite far from a scientific method at this point.

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I found this tip in the Glowforge Tips and Tricks section, straight from the horse’s (Dan’s) mouth:

You want to go the fastest you can at the highest power possible to have clean edges.


That’s a quote I’m gonna hang on to! Thanks.