The video Simon reffered to is here:
The finished product
A few specs:
Drivetrain - 4 cims through AM toughboxes modified for encoder feedback, two wheel drive with 6" IFI traction wheels in the back and AM omnis in the front, 10fps top speed
Launcher - Powered by surgical tubing, winched back with a van door motor and quickly released by a pneumatically actuated dog gear.
Hybrid abilities: Circle the track, knock the ball down in the home stretch, knock the ball down in the opponents home stretch, catch the ball. The IR sensor is used to direct the robot in hybrid.
Almost the entire frame is welded chromoly steel, the tracks that our forks ride in is galvanized steel garage door track.
Total weight of the robot despite all the steel is only 92 lbs without bumpers or battery.