Help Cutting 1" thick Soft Foam for Cases

[wolfsmagic]

Hey Folks,
Any tips on Cutting 1" thick Soft Foam for Cases etc.?
Is this even possible?
I need to create compartments within an ATA case for components to be stored using the typical soft black foam you find in cases.
I know this is typically die-cut but I am in need of smaller quatities and the die-cut set up fees will kill my profit margin.
Any help would be great.
Thanks
Chance Wolf
Wolfs Magic

[myxpykalix]

We did this several years ago and not with a bot, to make a custom foam case for my Steadicam.

We took regular soft foam and put it in a freezer and let it get hard then cut it with a knife.
I can't imagine you could cut anything like that with a router on a bot. I have seen where they have used(I forget the term used) a hot wire to cut foam.

[wolfsmagic]

Thanks Jack. I figured it may be wishful thinking but maybe someone else has found a trick for this.
Any help would be appreciated.
Thanks
Chance

[ljdm]

An electric carving knife works pretty well.

[benchmark]

I just cut a vacuum hose adaptor out of some hard black foam with a 1/4" upcut, it did the trick but the edges were a bit ragged.

What about a Zip bit ?

Paul

[myxpykalix]

I believe that any bit trying to cut soft foam is just going to catch and wrap the material around the bit or just rip it.

I don't remember if we did this when i cut mine but if you get the foam wet enough before you stick it in the freezer that might help it have enough structural strength to withstand cutting with a bit, but i doubt it. Its like trying to use the bot to cut a sponge, sometimes it just isn't the right tool for the job. Lou's idea about the electric knfe is a good one. Just make sure you clean out the foam before thanksgiving or the turkey is likely to take a bit rubbery.

[knight_toolworks]

Just mash it down with a ruler and use a sharp razor fast and easy.

[wolfsmagic]

Thanks for the input folks.
I have cut plenty of foam with the electric knife etc basically for straight block cuts.
My need is for more complicated inner cuts for odd shaped parts to fit within and time is a factor so hand cutting would be a bit much as they are pretty intricate parts.
Looks like I will have to sub it out to a foam die-cutting operation.
rats!
Thanks again,
Chance

[Brady Watson]

Chance,
You might want to investigate a very high RPM spindle that could be mounted on a ShopBot & used to cut the softer foams. The characteristics of soft foam require a very low chipload, and therefore, a very high RPM spindle. Pneumatic spindles come to mind, preferably something in the 100,000+ RPM range would be worth investigating. High RPM & multi-flute (4 or more) cutters are the key.

Your next challenge will be holding the foam to the machine while cutting. One cut/hold-down solution might be a tangential rotary knife. You should contact ShopBot directly and speak with their engineering dept, as I believe that that have built a similar type of machine for cutting leather. (RE: 'ThinLine Pads' on this page)

-B

[wolfsmagic]

Thanks Brady. Sounds like a good start!
Chance