816 experimented with a "Drive train in a tube" style frame this year, similar to Team 221 LLC's "Rockbox". Either side of the drive was put into a 4x4x1/8" Aluminum Tube, and the two tubes were welded to some 1x1x1/8" Cross tubes to make the frame. The Bare frame weighed 15lbs without any pocketing. If we were to have done some modest pocketing we probably could've pulled out a pound or two but we didn't see the need to.
Here's a picture of the frame with all drive components and electronics installed:
In retrospect, the frame was easy to build and plenty strong for a game with bumpers and moderately light weight. If you've got welding and some basic machining abilities, it's not a bad way to build a frame, though there are better options out there.