[tomp913]

Saw a link to this on another forum

Very interesting method of using a laser to level a 4x8 sheet sitting on top of un-uneven workbench to get it flat to start building a torsion box. He also shows a couple of innovative jigs for his pneumatic stapler to assure hitting the internal webs when stapling through the faces at assembly.

 

[tomp913]

And here is the clip where he demonstrates blind-stapling the one end of the internal webs and then pivoting it to staple the other end - very ingenious.

I have this old article on torsion box construction where the joints at the cross members are stapled on the face which may be quicker and, I'd guess, do the same job as there's only the need to hold the strips in place until the skin is glued and stapled on.