The RR 20X24 uses carbon fiber tubes. I would post a photo of the bed but am traveling and can not at this time. Even so, it is fairly complicated visually and I am not sure it would be easy to understand even with a good picture.
If I were to build a 20X24 camera again I would strongly consider the modular approach taken by Kerry Thalmann. I think the mono-rail design would be easier to assemble for most persons than a traditional wood bed design.