About this 3D model
I went ahead and plated up the various DXF's from http://www.thingiverse.com/thing:35372 . There are 3 plates that measure 2'x3' (609.6 mm X 914.4 mm) and 2 plates that measure 1'x2' (304.8 X 609.6) These plates should fit nicely on a variet of laser cutting machines.