It may not work for anything more than foam or light woods, I couldn't help but pick up 4 3x4 ft sheets of 1.3 inch plexiglass someone threw out. I've been playing with an XY table I put together to play with Mach 3.
 When I spotted these sheets I thought, Why not? It's still a work in progress. But here's a photo of it so far.

As you have said, it will have it's limitations but excellent work - my congratulations on your build.

Tweakie.