There was a set of plans for the torsion table needed for the 4x8 machine, I cannot find them.

My favorite explanation and video onhow to make a torsion box table comes from the Wood Whisperer. Part 1 of the torsion box video can be found here: https://www.youtube.com/watch?v=1-Hbsou6cWo Part 2 of the torsion box video can be found here: https://www.youtube.com/watch?v=cPDXKbbHENQ