CNC millers - Help ID this foam

[Yodajammies]

I really don't want to drop $texas on professional grade carving foam designed for milling on this project I'm working on.

Some of you might have seen www.legendaryarmor.com

Here is a shot of their straight off the CNC helmet. Looks like its done in two parts, so probably a 5-axis mill, etc etc.

What I am interested in is the type of material used here. Is this just very dense mattress foam? Something like this? : http://www.foamdistributing.com/products/hd36-hq.html

Or it is a product more akin to this:http://www.mcmaster.com/#machinable-foam/=1jzkhs (at the bottom)


Does anyone have an experience milling cheap locally available foams? Is it actually possible to get incredibly crisp edges and high resolution out of these materials? What kind of properties do these high density urethane foams have? What would be a recommended density to produce very geometric, hard angled parts, that can be molded and milled?

Thanks guys!

 

[noble]

6lb foam is too soft. (like flora box foam)

I recommend 10 lb. (gets more expensive the higher density)

Google Manufacturer- Coastal Enterprises, they could set you up
with a local dist..


At school they called it "Polyurethane Foam"

 

[ruze789]

In their build thread on the 405th they said it is 18 lb sculpting foam.

 

[Yodajammies]

ah, must have missed that part. Thanks

 

[Java]

Commercially available Ren-Shape Boards (a bit expensive)

You can buy liquid Urethane foam kits and make the blocks yourself too.

 

[Yodajammies]

Commercially available Ren-Shape Boards (a bit expensive)

You can buy liquid Urethane foam kits and make the blocks yourself too.

Any experience with this? Cost / pain in the ass ratio?

 

[Java]

make the blocks yourself.

 

[Jimbo890]

Balsafoam is an option too. All this stuff is expensive though. Try Smooth-on's Foam-It15 to cast your own machinable foam blocks.

 

[noble]

Renshape or Cibatool is way too expensive.
It will take a lot longer to mill (more $), and has a density similiar to wood.

10 lb foam is perfect, and you can't dent it easily like 6lb.

Making your own block will have air pockets and won't be uniform.
Also, might have a hard time convincing the CNC guy to run home-baked
foam on his expensive mill.


Mattess foam can't be milled. That is different.

You can probably get a better price other than McMaster.

After you mill it, there are a few techniques to finish it to a smooth
surface.