Lower cost machinable foam sheets?

[vaneeck1]

I am new to cnc milling of foam, but it seems I am having trouble finding any lower priced foam sheets to mill.

What I need is sheets as large as 4x8 ft and 1 or 2" thick. I am milling 3d surface contours into the sheet and then painting them, a bit like a sign making shop, but they are not signs. Any sign shops out there who would be willing to give me some ideas?

any sources of more economical foam products would be greatly appreciated.

Greg

[JPMach]

I get mine from Goldenwest Mfg, not exactly cheap though as a 24" by 60" by 2" piece in 20 lb density runs about $170 plus shipping. Great stuff though. They do make a 15 lb density that is a little cheaper, but I use the 20 to get some good details in. You can easily glue pieces together to get bigger sheets or I believe they do sell up to 5' by 10'.

If you find a decent place that has comparble stuff for cheaper please let me know.

JP

[keebler303]

all depends on the density you need. i have used some polyiso foam from john mansville and some stuff called R max (not sure if that was the brand or product) it is low density (1-3lb) but its dirt cheap. its main use is insulation and its around a buck a square foot.

Matt

[vaneeck1]

Originally Posted by keebler303 all depends on the density you need. i have used some polyiso foam from john mansville and some stuff called R max (not sure if that was the brand or product) it is low density (1-3lb) but its dirt cheap. its main use is insulation and its around a buck a square foot. Matt

I had been looking for something in the 6-10 lb density, but its interesting to hear you tried some regular insulation foam. So what did you make out of it and how well did it seems to work?

Greg

[keebler303]

i made molds for artificial rock climbing holds. they are cast resin. i used a dremel and grinder to shape it. it works pretty well. i also have used it as a core for composite parts. it isn't very durable by itself but if it is coated with something ie. fiberglass it is pretty tough stuff.

[stevesplanes]

What type of tool head are you using with the dremel. What sort of feed speed are you capable of. Does the foam frament or melt at such high rpm.

[jimini]

I don't know if this is of any help, but check it out.
http://www.elegantice.com/liners5.htm

or:

http://www.shopmaninc.com/foam.html

[keebler303]

Originally Posted by stevesplanes What type of tool head are you using with the dremel. What sort of feed speed are you capable of. Does the foam frament or melt at such high rpm.

use approx 1/2 gringing stone head in dremel. all work i have done was manual but i would estimate feed to be around 60-80 ipm. no fragmenting or melting occurs. it is not dense enough to build up heat. also will add i have used a 1/4" carbide GRIT burr in a standard router and it cuts as fast as you can move the router.

Matt