Hey all! Right now on my 4x8 PRS I've got a pretty standard table setup:

Bottom layer is plywood, middle layer is sealed MDF with plenum routed into it and the top layer is LDF (Trupan). All three layers are glued together.

This setup has worked for several years got all of the plywood I've been cutting. Recently I've picked up some regular production work that's all in plastic. One job in particular requires very accurate pocket depths.

What I've been finding is that the Trupan moves daily, I'm not all that surprised by this.

I'm exploring ideas for a new table. I've priced out aluminum extrusion which I'm sure would work, but it's a LOT of money.

I've also looked at making my bottom layer and my plenum out of Extira. From everything I've read it seems to be really stable. My thinking right now is that I do that, and instead of glueing down my LDF I leave it loose and only put it on when needed. (I could keep it from sliding with some pins)

For the rest of my plastic cutting I have jigs that I could place (and vacuum down to) the plenum directly.

So the question(s) are: Has anyone else fooled around with building a really stable table? What materials have you tried?