I’m making road cases for some audio equipment, and I’m wanting to custom cut the foam for the drawers. This stems from my long-standing hatred for pluck foam 
Any recommendations on foam types that are safe to cut? It’d be nice to be a neutral color (black, grey, etc), but not necessary so long as it’s not “pink foam”
You could steal an idea from those who ship and use an expaning foam to create a form fitting fill.
I have use the expanding insulating foam you can get from the Lowes, Home Depots of the world. I wrap my object in multiple layers of packaging plastic to protect it. I then place a layer of the foam in the base of the box, place the plastic protect item with one side level with the top of the box, and add some foam (in small bursts it expands a lot) until it fills all around. I let it dry and then remove the item and with a hand saw level the foam with the top of the box.
As long as you wrap your piece well and are careful not to use too much foam (it expands a LOT) this has worked well for me.
For foam suppliers, you might check out: Quality Cases in Richardson, or TCH Hardware off of 35E/12 in Dallas
Maybe someone more knowledgeable than I can look at the foams listed in the link and tell you if they are safe to cut on the laser.
Hot knife is the proper way of cutting the polyethylene foam used in the cases. It tends to cut easy and leave a really nice finish. Plus you can draw your items and laser cut cardboard templates to follow. I have to cut foam for a gun case and am planning on trying to do it with the laser, I’ll share my results and process once I’ve tested it.
Expanded Polypropylene & Expanded Polyethylene Foams. Both are soft but very durable. I believe it is the same type of foam used to make pool noodles. Use a hot-knife or hot-wire to cut it cleanly.
http://clarkfoam.net/foam-products/expanded_polypropylene_expanded_polyethylene_foam/
Thanks guys! I think the polyethylene foam @Joseph_Helmstetter and @Nick mentioned are what I’m looking for. @Nick, have you had a chance to test this out yet?
I wish I had, been putting off my own projects for time helping with logistics, finance, hatcher’s and creative arts committees. Feel free to give it a go, be very aware of the chance for catching fire. Many foams can catch fire easily.
Nick, following up on this… did you ever try to cut the polyethylene foam with the laser? And if so, how did it turn out? @mattarmstrong, did you?
I haven’t, I’ve wish washed back and forth as to what I’m going to put in the case. So like many projects my indecision has kept me from finishing.
K. All good. I’m going to grab some in the next week or so and start playing with it. I’ve got some old pelican cases I want to redo, and some new NFA toys that need protecting.
Any updates on these projects? I’m thinking of getting some foam for custom cases. Looking at PE or PU foam. Any restrictions on either?
Polyethylene is listed on the DMS do not cut list, although there are places that do cut this with lasers, I believe the main reason is that it tends to melt and make a mess if you don’t know what you’re doing. However, I also see sites say that it is OK to cut with the right kind of laser. https://www.ulsinc.com/materials/polyethylene-foam
Polyurethane is not on the do not cut list. It isn’t on the safe list either. If it truly is safe, and doesn’t make a mess, we should update that page.
From what I read below, it looks like Polyurethane should be safe in that it vaporizes when cut and doesn’t necessarily provide harmful gasses that the exhaust system can’t handle. (see the last link below)
Here are a couple of references I found on the subject:
https://www.troteclaser.com/en-us/applications/foam-filter-mats/
https://www.ulsinc.com/material/foams-overview
https://www.ulsinc.com/materials/3m-microcellular-polyurethane-foam
Has polyethylene been removed from the do not cut list? I do not see it on the page unless it is called something else.
I don’t think it was specifically discussed at the last Laser committee meeting. HDPE and LDPE will stay on the list. PE foam is basically the same stuff with bubbles in it.
Are you looking to use an open-cell or closed-cell foam in your cases?
Open cell Polyurethane foam (like what is also commonly seen in road cases) is not on either list, and based on reports should be safe. You will be limited in the depth of foam you can cut and probably shouldn’t attempt more than 1" because of the hourglass shape of the laser focus point. You could cut multiple layers and then stack or glue them together with 3M spray adhesive.
In any case - you’ll need to WATCH it extremely carefully. Test with lower power and higher speeds and try to keep the laser head moving as fast as possible.
@heyheymama is the Laser committee chair and would have the last word on this though.
We need to review the list at the next Laser meeting. The wiki list differs from the Class materials list, and Thunder Laser has another list.