I am only cutting at 100ipm, the foam isn't melting it just deflects badly. The squares are going to be a vacuum box that is expandable by just taping each one together until you get the size you want
Jeff, that is my point. You may think that 100ipm is not fast but to cut the DT foam we used almost 100ipm at a very slow spindle speed. Maybe increasing the spindle speed and using less ipm will prevent the bending? But than again, if it is the same material as the DT foam it will gum up the bit, which is why I've asked if it is the same material.
I an 99% sure that Model PLane Foam is the same as DT foam without the paper. From what I understand from an old thread on RCG, it comes from the same manufacture, Adams, and is made for those guys speced to their size with no paper.