I've just found this out, and I thought I'd post it here because it was really useful for me.
The robonauts have put up CAD models of their 2007, 2009, 2011, and 2012 robots, which are really neat, very detailed, and some of the best CAD work I've ever seen from an FRC team. I now know how their massive gearbox in 2007 works!
You can download them from here
http://ccisdrobonauts.org/?w=1600&h=900&p=robots