Just about everything on our robot each year has been taken into consideration using CAD. We train several students at the beginning of the school year to learn the basics of using a CAD program (we use ProE), and then when robotics start, nobody has an excuse to not participate (at least those working on design, and the robot itself).
The more time you spend on designing and integrating your robot on CAD, the easier, and faster it is to assemble the actual robot. Just make sure you give your team enough time to order the parts you may need (another reason to use CAD).
