Foam cutting with LowRider

Has anyone here had experience cutting this kind of foam? I’m trying to use it to CNC car panels for fiberglass work.https://www.homedepot.com/p/Owens-Corning-FOAMULAR-150-2-in-x-4-ft-x-8-ft-R-10-Scored-Squared-Edge-Insulation-Sheathing-45W/100320352

Haven’t personally done it, but the specific brand “Foamular” is mentioned in the milling basics guide.

https://www.v1engineering.com/milling-basics/

If you’re going to be cutting the foam instead of milling it, maybe look into the hot knife to get clean cuts.

I use that foam all the time to do tests. It ends up being very sharp. It’s also very low resistance. It makes quite a lot of nasty dust though.

I dont think a hot knife is a good idea, sorry.

If you’re planning on doing large 3D carving, it is going to take a long time, so I’m assuming you’ll want to go pretty fast. I’ve never tried pushing the limits with this foam, as I’m usually testing gcode meant for wood. It’s the only material where you can probably get away with larger bits and full depth passes.

So I could use it but it would be sharp so I would have to sand it down a lot.

No, by sharp, I just meant that it retains the detail.

There will be some sanding though, I’m sure. I don’t know much about the rest of the process, but presumably you’re going to do something else to it (add bondo, use it as a form for something else) before attaching it to the car.

Yea, it will be able to go pretty much as fast as the Z axis will allow it.

Do the rough cuts with the largest end mill you can fit on the machine and go as fast as you can.

Then go back with a large bull-nose to clean up the rough edges.