Underlayment not cutting

I’m hoping someone can tell me if I am testing this material correctly.

I adjust the speed lower, and focus height higher. Do I adjust the power?

Thanks for the help. First time I have encountered this problem.

The focus height should, in my opinion, be left untouched unless you want a defocused engrave or cut for some reason.

Here is Glowforge’s discussion of using the manual mode: Working With Manual Mode – Glowforge


I read that article. Unfortunate I did not find a solution there. Maybe it’s me. So leave the focus height alone. Only adjust the speed?

Some of the articles I read adjusted the height. I don’t have a good enough idea on how the focus works. I used calipers to get the focus height in inches.

I’ve been at this for days and so frustrated. Any more advice??

You can let the machine auto focus for the height if you are cutting things on top of the honeycomb tray. You want the laser to be focused as precisely as possible because that is the way it generates the most efficient energy in the spot you want it to cut. Changing the height is telling the laser to focus somewhere other than the surface of the material.

Think of the laser as a blowtorch. If you have a big flame and move it slowly, you will have one kind of cut. If you have a big flame and move it quicker, the result is different. If you have a focused flame and move it slowly or quickly you will get a different burn.

Are you cutting with the honeycomb tray?


If you are cutting without the honeycomb tray, the material must be elevated off of the floor of the Glowforge so that it is within the 1/2" focus range of the lens. This means, the top of your material must be between 1.5" and 2" off of the floor of the Glowforge without the honeycomb tray. Once your wood is elevated into the proper focus range, allow the auto focus to set the height.


Some plywoods just won’t cut. I bought some gorgeous luxury ply to test, and can’t get through a single piece of it, even though it looked like it would cut nicely on a laser (poplar core ply). If the glue layer is very thick between the veneer and the inner ply core, the laser won’t cut through it.

Underlayment is the cheapest of ply and is meant to go on floors in house construction. It likely has all sorts of undesirable and hard to cut issues, such as thick glue, voids, knots, metal glitter, etc.

If you are having that much trouble, I suggest trying a different ply, such as I wrote to you in the message that you sent me about underlayment settings, or doing a test cut with the Gift of Good Measure Keychain to confirm that your laser is still cutting well.


Leave focus height alone - adjust speed and power.

Yes I am.

ok thanks - I’ll try to cut the GOGM - didnt think of that.

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Underlayment is a type of board intended to be used as a floor coating, it is denser than normal plywoods and typically includes some sort of moistureproofing treatment. Since it has been formed under higher pressures, it’s typically harder to cut and engrave, so you’ll have to work with your settings to see if it’s even possible. Work on the speed and power balance, increasing power but trying to avoid excess char and flareups, then adjusting speed either up or down to ensure complete through cuts, again watching for excess char and flareups.


Just for clarity, the focus height has nothing to really do with your cutting. A lot of people think that by putting in the ‘height’ of the material ie… .125, it adjusts to cut that depth of material…the only thing that’s going to help with ‘cutting’ is as everyone has stated above…slow down your speed or increase your power.

It’s pretty much covered above.

“Underlayment” is pretty much the lowest grade of plywood. It’s designed to be nailed over rough construction to provide a smooth surface for tile or carpet.

It’s very inconsistent - and that’s the key. Settings that work on one piece of even the same sheet may not work on another.

I’ve used a fair amount of “Lauan” (from Lowes) but you just have to be prepared for the fact that it’s dirt cheap for a reason.

I haven’t bought any since THD started selling “Purebond” ply in GF-sized sheets.

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Hello! @grimmer5906 I am sorry to hear about the trouble you are having with cut-through. I will do my best to get this resolved for you. The first thing I would like to do is establish a baseline to make sure that the Glowforge printer itself is operating within specification.

Please perform the following test print.

  • When the print finishes, leave the lid closed and wait until the fans stop and the picture updates.

Check the completed print:

  • If the Gift of Good Measure fails to cut through, take a photo of the front and back of the print and attach these photos to your reply.

  • If the Gift of Good Measure cuts successfully, please try another print of the design you experienced the issue with, and let us know the results.

Once you reply back with those photos I will be more than happy to help with next steps! Thank you!

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