I am taking a more flexible approach. I want to be able to swap in/out different surfaces, depending on what I am working on. For example, anything that I am scanning (thin or thick) can live comfortably on 1/2" MDF or particle board. I plan to have several tops, with different jig setups for some of my standard projects. Put the top on, place the material into the jig, load the job and hit start.
For cutting, I am going to use true aluminum honeycomb - purchased at McMaster Carr. It is one inch thick and will easily support anything that my system is capable of cutting. The inch thickness won't steal any usable height, as I can cut anything over 1/4" or so, anyway.
So the obvious question is, how do I swap in/out these different tops? I drew up an idea last week. It works on the principle of having fixed positions for locating pins on the table frame. The table tops have matching holes. The pins are actually 5mm socket head screws with a 10mm x 5mm high spacer. The whole pin then is 10mm high and remains below the surface of the 1/2" table top material.
[photo - removable table top drawing]
I actually implemented one top over the weekend and it works great. Since the spacers are plastic, I dropped the table top in, snugged up the 5mm screws just enough to slightly expand the spacer's diameter and it "locked" the board into place. I made a drilling jig so that the holes in the tops will always be located exactly where they need to be. Don't want to have to move the pins for the different tops - they have to be the same every time.
The only thing I have left to do is decide how to frame up the honeycomb so it can drop in as easily as everything else. I suspect some type of aluminum z extrusion frame with the honeycomb in the center.
One major advantage to this approach is the ability to remove the top altogether and pick up about 2.5" extra material height, when necessary - like when I want to drop in a rotary attachment.
When I get the cutter top worked out, I will do a post with pics of everything in action.