Cutting EPP foam

[wink]

I'm contemplating using ShopBot to cut Expanded Polypropylene foam (EPP). I've seen quite a few posts on the forum relating to foam but they seem to be referring to Expanded Polystyrene (EPS) aka Styrofoam which is much harder than EPS. EPP is spongy but tougher than EPS.

Does anyone have experience cutting EPP and if so what bits, feeds and speeds have been used?

-- Wink

[steve_g]

Wink:

I've never routed EPP (knowingly) however I have routed lots of 1 & 2lb. PE foam for case inserts. My suspicion is that they will route similarly. I can only describe the finish as "fuzzy" however, a quick pass with a torch cleans it up nicely. Maybe you can develop a hotwire tool to chuck-up in your router!

Steve

[wink]

Wink:

I've never routed EPP (knowingly) however I have routed lots of 1 & 2lb. PE foam for case inserts. My suspicion is that they will route similarly. I can only describe the finish as "fuzzy" however, a quick pass with a torch cleans it up nicely. Maybe you can develop a hotwire tool to chuck-up in your router!

Steve
Nice to hear, they do look similar. What bits, feed & speeds did you use?

[steve_g]

I found little difference in bits or speeds, you're basically ripping out chunks of foam. Since I was pocketing recesses for test equipment, I used a 1/2" straight bit to remove material faster. The real challenge is holding the material down!

Steve

[myxpykalix]

Now i have never done this on a shopbot but have cut foam with a saw and knife using this. It may not be the same type of foam but you could try it.

I took foam and soaked it in water and stuck it in a freezer and got it pretty much frozen then took a electric carving knife and cut out sections to make a new insert in my anvil case for my steadicam.

I think i would do like Steve suggests using a straight bit. :eek: