With the torsion beams completed, I laid them out across two sawhorses and used shims under the legs to get the torsion beams level in both directions. I placed a sheet of MDF on top of these beams and proceeded to build up the base for the machine.
As you can see below, the pattern of webs is not uniform. I was originally planning to have it filled with the square pattern seen at the ends. However, I changed my mind and decided to go with a sparser pattern. It should provide plenty of rigidity for this prototype.
The glue-up was done in two stages, first to attach the sides and all the webs to the base, then to attach the top. Many clamps and weights were used to hold everything together while the glue dried. With the top in place and everything glued up, the assembly is very stiff and doesn’t flex at all when lifting up on a corner.