Routing open cell foam

[araugh]

Hey there folks, did a bit of searching but did not meet with much success. Does anyone here have any tips for routing open cell charcoal case foam (similar to this: http://www.thefoamfactory.com/opencellfoam/charcoal-F.html), like is used in pelican cases? We have a customer who is buying a few hundred of our lasers on a very accelerated timeline and my local case suppliers can't meet the deadline. I can go with pick-n-pluck but this is a fast paced international tour and these things will be pulled in and out of the cases hundreds of times in just a few months so it needs to be sturdy.

I've done some testing using an Onsrud 40-562 and came nearest to success at 18000RPM, 2.5IPS, conventional cut rotation, but even then it still has a somewhat rough edge.

Any advice would be greatly appreciated or if someone with experience has the time and interest to do it within the next 9 days please contact me so we can work out a price. Equipment is a PRS Alpha 96x60 with 5hp colombo spindle.

Thank you

[myxpykalix]

a long time ago we soaked it in water, froze it and then cut it with a breadknife. Maybe a combination of pressure foot and dragknife (if that's even possible:confused:)

[Mayo]

I have never cut that kind of foam myself but I believe most companies cut it using either laser cutters or water jet or hot wire.

Rotozip makes a 1/8 inch and 1/4 inch tile cutting bit which has little sharp pyramids all over the cutting surface. This may have the effect of sanding through the foam instead of pulling and slicing and leaving the rough edge you mentioned. Cheap enough to try on some scrap...

[araugh]

ah well. Thanks folks

[twelchPTM]

i have cut similar foam, I made boats and rockets for use here at the museum. It can be a bit of a pain getting everything right but it is possible. I tried several different kinds of mills with different geometry and it turns out a plain old 2-flute upcut worked the best. Feeds and speeds are another issue, There is really no way to say what speed to use because it will vary from piece to piece based on actual density. domestic foams have much tighter tolerances on density them imported foams ( I was cutting 4lb foam but actuall density ranged from 2.5 to 5). the denser the foam the faster you can cut. it does take some experimenting to get it right but it can be done. also shortly after I finished my project I got an e-mail about a brand new mill designed for cutting this type of foam. I will see if I can find it and post if I do.