Hey Terry,
that is always an important thing when assembling a torsion box.
The other day we were discussing how to ensure that the table top you glue/screw together will not be twisted, and what I suggested was:
You may still use a torsion box that is twisted by mounting the Onefinity on it, making sure the feet are all in one plane e.g. by using shims (I would use metal sheets cut out to match the machine’s feet including the holes), and then surface the entire workarea. If you eliminated the twist in the machine by using the shims, you will get a non-twisted workarea, and for the remaining area outside of it, which will remain twisted, you could either leave it this way or remove the material with a hand tool and by using a long straight edge, with the non-twisted workarea as reference.
Another thing I thought of that you can find on some CNC machines, is to mount one of the machine’s feet on a base with adjustable height. Since three points are always in one plane, it’s always only one foot that remains to need to be adjusted.
The QCW Frame
The QCW Frame meets the demand to have a machine that when assembled is immediately ready to use. With the separately available adjustable feet¹, an existing table may be twisted or uneven and if you do not have a table at all, you can also set up and operate the machine on the floor.
However, the QCW frame is rather expensive, and the target audience for a Onefinity is actually people who can build a base for the machine themselves as desired and needed, and therefore do not necessarily need the QCW Frame. For example, many people here want a machine base that allows vertical clamping. And if you think of the money that the QCW Frame costs, there are many things that you could find more urgent to buy, for example a professional dust collector or a vacuum table.
1.) The Any Surface Leveling System provides these inserts with threads that are not part of QCW Frame: