I'm a bit confused by what you mean when you say, "reinvent the wheel." If you are referring to designing your own robot, that is the entire purpose of VEX. The nature of robotics is such that every robot is different. Having your students build something beyond a claw bot means they must design it on their own. Now, this doesn't have to be a super complex bot like those that are built for competitions. A good guideline for that would be to have students build a simple drive train with four c channels, 2-4 motors, 4 wheels, some bearings, and a fourth c channel that goes across the top to link everything together. This would use concepts from the clawbot and still be something different, yet simple. To reiterate, stop looking for premade instructions or code. VEX parts are made easy to fit together, etc. to facilitate custom designs more easily.