Dispatches from the front (Pre-release Report) - cutting felt

I’m making a living hinge glasses case using Proofgrade maple plywood. It will be lined with felt to keep from scratching the eyeglasses.

Easy cutting the PG, but what settings do I use on felt? I’m using a self-adhesive craft felt from Michael’s. The stuff is 0.075" thick with a peel off liner on the back.

Into the 'forge, load up my cut line test file and start testing. My cut line test file is simply a set of 2 lines, one vertical and one horizontal. If I want to cut a piece off material I can set the GFUI to ignore one of the lines, set the length and place it where I want the cut.

In this case I used both lines as that gave me two tests for each run. I started with 100/100 (power/speed) and 100/197. 3 seconds later I knew those were too hot/slow.

Since I can’t go faster with a cut than 197 in/min, I had to start dialing down the power. I approached it with a binary search for the right setting. Each change was half the prior one. If you go too low, the next one goes back up by 50%. It makes zeroing in on the right settings pretty fast.

Since 100/197 cut right through and I was trying to get it to just cut the lining paper, I tried 50/197 & 25/197 next. Worked my way to 1%/197. This cuts the felt through and almost entirely through the lining paper - enough that it’s almost like the paper is perforated. At 3%/197 it’s clean through both.

Here’s my little test piece:

The silver disk is a quarter sized 1.5mm thick neodymium magnet. A little piece of felt like this will blow away from the air assist :slightly_smiling_face:

Here’s the back side of the last test:

Now I could cut my lining felt and work on finishing the eyeglass case. Of course I could have cut it out with an X-acto knife faster but only because I needed to find the right settings. From now on, especially for intricate cuts, the razor knife doesn’t have a chance.


Why in God’s name would you ever think or have a knife again??


Thanks for the research! I’m pretty sure the adhesive backed felt from Michaels is the synthetic variety. It would be interesting to see if the same settings work for 100% wool felt. As I recall @smcgathyfay did a test…

Yes, here it is: https://community.glowforge.com/t/laser-cut-100-wool/

Hmmm…having trouble linking with this iPad, let me know if it doesn’t work.


Especially since you could use a Sharpie on the release paper on the back and use the GF trace feature to trace & cut it (felt side down).


That’s great! My wife and I were discussing last week if felt would cut nicely (or just melt horribly)!

Real wool felt cuts well (but smells - you’re burning animal hair). Polyester felt (Michaels, craft store stuff) cuts well but doesn’t smell :slight_smile:


A knife will always be needed… If something doesn’t fit inside the GF :smile:


Duh. Yeah. When ya say it, of course! :slight_smile:

Very likely where we get all of our felt from. Good to know! :slight_smile:

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Is polyester safe to laser?

I’m only guessing it’s polyester. It could also be acrylic. I can’t find the MSDS but I did the torch test on it once before (when I was making a living hinge purse for my wife) and it didn’t produce chlorine.


binary search trees are one of my favorite useful “real-world” algorithms

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Oh my gosh I think I’d use a knife just to avoid the burning hair smell…


What setting you use in the polyester felt?

I did some tests on some adhesive backed felt with what I would imagine is the new system.

I used a speed of 195, with a power of 10. Focus height of 0.075. It cut out the felt, but not the backing.


Good to know. Thanks for the update. I haven’t run material calibration tests yet on my new Pro - that’s on the to-do list :slight_smile: