Is there any kind of thick (1 to 2 inches) relatively rigid foam material (i.e. consistency similar to white styrofoam, like an ice chest, or maybe a bit softer) that’s safe to laser cut?
http://www.toolfoam.com/. You can glue several layers together and this is laser safe. Can use it to make either a custom tool layout for your toolbox or for a custom insert to hold say a drone in a hard case.
Cool–I’ll check it out!
Cooler foam is EPS: expanded polystyrene. It is the relatively low-density, little foam beads pressed together-style foam.
Insulation foam is XPS: Extruded polystyrene. This is the pink or blue stuff you can get at Home Depot/Lowes. smooth finish, solid cross section. Usually has a plastic film on either side (sometimes foil/metal instead).
1" is readily available: 2" is available in colder climes (though I have some of both in my garage).
What are you looking to cut: size, quantity? I might be able to give you the XPS you need.
It is most easily cut with a hot-wire foam cutter. There are hand-held versions, and I’ve made a hot-wire foam cutting table I could loan you: works kinda like a scrollsaw in technique, though the “blade” is a piece of nichrome wire heated via a 12V DC transformer. The foam is pushed into the hot wire and is cut as the foam moves along.
The Toolfoam.com material that @gkitto63 mentioned is Polyethylene (PE). They don’t say what kind of PE, but from what I’ve read PE can be hard to laser, esp. the higher density variants) because it tends to get melty and flow back together after lasering. Lots of air can help.
Depending on what you have planned, a long boxcutter blade (aka a snapblade) might be a better option for PE.
*Edited to get EPS and XPS straight in the post, if not in my mind.
Closed cell polyethylene(4lb density) is what I used to make the tool trays in the auto toolbox, cut on lasersaur cleanly with no issues
The problem with laser cutting any material 1" - 2" thick is beam divergence. It is very hard to get the beam to focus in such a way as to cut all the way through. It would be better to cut 1/4" or 1/2" sheets and laminate them to get the thickness you want.
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MultiCam is a good option for higher density foams, but I’m not sure what the exact rules on that are… you’d definitely want to buy your own bit.
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Thanks for the info. My challenge is that I need to cut 48 1/2" holes (in two straight lines, with fairly accurate spacing), so I don’t relish trying to do that by hand 
. Also, the total thickness I need is about 3", so I expect to have to cut a lot more than 48 holes in several pieces of material in order to create a “stack up” to get to my desired thickness. And on top of that, I need 3 sets of the final result (about 24 x 30 inches).
I’ll explore the EPS–do you happen to know if it’s laser-safe? Otherwise, the 1/'2" PE may be the best solution.
Yep. I had already planned to create a stack. I though maybe I could get up to 1" on the laser with multiple passes (some experimenting is to be done).
Very interesting. That’s an option I hadn’t considered. I can definitely use a denser foam than PE; it doesn’t have to be “spongy” for my application, just lightweight. I could almost use wood if it weren’t for the weight.
Easily done on the CNC Router, but requires taking CNC Basics, and Advanced CNC to cut plastics. We do have the bits…
You can also set up a drawing in vCarve, and see if one of the CNC folks will run it for you. Foam jobs are easy and fast,
I would buy 3 sheets of 1" foam insulation board (pink or blue), cut them, then glue together. Dead simple job on the big router.
Just lay out the sheet, with the circles placed where you want then (use copy and distribute command). Use a 1/4" “O” bit, highlight all the holes, set them to profile on the inside of the vectors, set the cut depth a few hundredths more than the thickness of the foam, set the plunge rate high, and whack em out.
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We can look to move the advanced class to the LMS system in the near future. I am in the process of putting the class room portion of the CNC Basics class on there. Hopefully we will only have to do test outs at some point.
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Hmm. May I point out, that since the problem is “no hands on experience or operational training”, that moving online is unlikely to solve the problem, but potentially likely to make it worse?
Videos or online powerpoints are fine for a lot of subject matter, but where tools in general (and expensive tools in specific) are concerned, there’s no substitute for hands-on supervised training. And a bad gamble could cost us (Woodshop) an awful lot of money.
I could see moving the vCarve, background, and even bit selection and F&S online. But it needs to be paired with a session at the table, for some see and do time.
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https://www.5ssupplies.com/5s-tool-foam/ (through amazon) but it looks like toolfoam.com is the same stuff
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That sounds like the perfect solution. In fact, I’m taking Alex’s CNC Basics class tonight.
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IDK if it is laser safe but the home depot on 75 in plano had 2" polyurethane foam (pink)
http://www.homedepot.com/p/Owens-Corning-FOAMULAR-150-2-in-x-4-ft-x-8-ft-R-10-Scored-Squared-Edge-Insulation-Sheathing-45W/100320352
I bought a whole bunch from them but we spent 30min wandering around the store looking for it and they were chatting about sending it back to distribution.
A little bit of poison is healthy right?? 
edit: apparently it is actually a polystyrene product…idk if that is better or not.
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The 2" stuff doesn’t seem to be one those things that are normally stocked around here and I am almost tempted to buy a sheet of it, just in case…