My group's RC robot for school had a similar design. It used what we called daisy wheels in order to traverse 2x4 obstacles. The robot had to take a load of ping pong balls and dispense them in a bucket. The design was great, because it was very simple. I just had to ram the bot's ping pong hopper into the scdoring bucket to dispense the balls. The problem was that we were told the bucket would be affixed to the floor. At the competition they changed the rules to where moving the bucket was a 30 second penalty. Without the penalty we would have gotten second.