Cutting Foam Outlines In Cases

Anyone tried cutting open-cell foam or kaizen foam on their CNC?
The type used in storage cases for cameras, tools, or other equipment.

Is there such a thing as a hot knife attachment for a CNC?

I am looking into if this is possible as I may be making some cases with
custom interior sized to specific pieces of electronic equipment. Similar
to a Pelican case.

Supposedly endmills will just cut it

Use a plastic cutting end mill. Highest speed on the router & 200ipm for feed rate as a starting point.

I use blue tape & CA glue to hold it down. Otherwise double-sided tape works (but may tear out the foam a bit when removing it.


Did some tool inlays today.
I used a Datron 6mm 3 flute foam endmill, 120ipm, 0.375DOC, 70% stepover and conventional milling (not climb). 16k RPM.
Very conservative feed, will increase it but for a first try it worked fine.


Awesome, that’s just what I want to do. Nicely fitted with finger lifts in Kaizen foam.

That looks to be a very functional and satisfying project! Did you get information on feeds and speeds from the endmill or foam manufacturer (or personal experience)?

Thanks, I will give this a try once the foam arrives.

Now to figure out how to create silhouettes of the objects that I can get into V-carve.

I have a couple radios that I want to make foam inserts for and they will need to more than just a rectangular opening. Will need cut around multiple knobs and other protrusions on more than one face of the equipment.

Shapes like wrenches, pliers, knives, chisels, for tool storage and even larger items like making a fitted insert for a shotgun which I got a request for but don’t know where to start with that.

For smaller items I was thinking I could stick them on the scanner bed and then import that 2d image to get the outline of the thing, then work from there. Don’t know if that will work no doubt there is a better way. I will have to do some searching.

As this is also something I had looked into, and plan to do, I remember coming across a few tutorials on doing just what you mention - object>photo>image file>CAD - using F360.

If you use Fusion360 it is easy to do there are many tutorials like TMToronto mentioned. I’ve made replacement parts for people from a photo and a measurement, import the pic into Fusion, scale the canvas based on the known measurements and then work from there.


what foam is that? I am not a Kiazan fan. Foam is turning out to be harder find than one would think.

Yes, I would love to get some sources for reasonably priced foam, that carves well.

I use sheets of insulation board from the big box stores. Decently priced vs some of the closed cell foam alternatives. Use dust collection :joy:

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Is it pink, or do you spray paint it?

I’ve used both pink & blue panels. For personal use or packing things for shipping (with custom cutouts) I leave it as is. When I use it for stuff like theater set pieces I paint it. If you paint, make sure to test the paint on scrap first - some paints have solvents that will eat the foam.

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I wonder if you could spray the insulation board with plastidip or something just to keep it from ‘shedding’

Interesting timing - How to Cut EVA Foam on a CNC Router - YouTube

I’m interested in that foam too @Bastien - where did you get it?