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


#1

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.


Living Hinge D&D Boxes
Weekly Highlights for the Week Ending April 22nd, 2017
#2

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


#3

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.


#4

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).


#5

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


#6

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:


#7

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


#8

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:


#9

Is polyester safe to laser?


#10

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.


#11

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


#12

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


#13

What setting you use in the polyester felt?


#14

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.


#15

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: