Official Luthiers Forum!

Do any of you use foam to test your designs out before cutting wood? I'm interested in finding a source of something relatively cheap that I can use to test out programs and wondering if anyone has any suggestions on where to find a source.

Ideally it would be something that machines nicely but still is cheaper than wood and is easy on the tools. I think at I need about a 3" thickness to test out my stuff.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

I per say have not used foam to test a design....I usually get pretty close with a simulation in mastercam, and when doing say a carve top, which I do not want to ruin for a first run, I have used cheap Pine from Home Depot to do a test.

There is machinable foam specifically designed for this (google it) but not sure about price.

I have seen folks also use the thick foam you find a home depot for insulation (the pink stuff). A sheet of that is very cheap, but I have personally not cut it with a router, to see how it machines. There are a couple of folks on cnc forums, which did this, with good results. it is very cheap to try it, so that might be an idea...

_________________
-CyborgCNC
http://www.cncguitar.com
https://www.facebook.com/CncGuitar

I have several junk pieces left over from doing this.....

I can tell you the foam will work ok for testing your 2d stuff, but not so good on the 3d. It has a tendency to fuzz pretty bad, and I don't know whether or not it would be of benefit with the fuzzeys!

Mike

When I was a tool and die maker I used to make layup tools from that brown foam. It was supposed to cut like mahogany (the choice of material back in the day for foundries, etc.), but I didn't think it cut like mahogany at all. It also wore tool edges out at a prodigious rate - high speed steel, carbide, titanium nitride, even diamond.

I do think it would an excellent material for use in clamping, etc.

(what's the story on the Ferrari front clip?)

_________________
"Act your age, not your shoe size" - Prince

I know almost nothing about CNC, so maybe it's not the same at all, but at the last woodworking show I went to a chair making seminar. The guy said the single best piece of info he was going to give us was to build mock ups with the rigid foam board insulation from the depot. I forget if he was using pink or blue, but he said it worked easy with hand and power tools - drill, cut, shape, sand, rasp, route.... If you need thicker, you could glue a couple together.

Mike

_________________
Mike Lindstrom

I used to use this stuff...

http://www.generalplastics.com/products ... hp?pid=20&

Actually all I remember is that I got it from General Plastics...pretty sure thats the same stuff.

Although any dense, rigid polyurethane would work fine....as might a chunk of pine.

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

Splinters too easily in my experience.

_________________
"Act your age, not your shoe size" - Prince

Thanks guys. While searching I found this place: http://foamdistributing.com/ which by chance is local. They don't have any rigid foam on their webpage but I sent an e-mail and they do have a whole variety of rigid stuff people are using for machining.

The gal there offered to send three free samples so I asked her to send whatever the cheapest is and two of her recommendation. We'll see.


p.s. I received my Gecko and steppers yesterday....machine coming soon!

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Foam's really messy. We've always just used 2x4's glued together or mdf (messy in a different way).

I end up regretting it every time I use MDF for anything, but eventually I forget and use it to proof something. Generally I glue up a blank out of whatever's around, or 2x4s if nothing else will work. Doesn't take ling with CA.

That rigid foam Stuart mentioned is great stuff. More expensive than scrap wood, but it machines great. It machines almost too well, actually. It'll let you see the finish, but won't let you know where you'll chip out or burn in wood.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services