LEGO Mindstorms Class:  Tug-of-War Challenge!

This class we will build robots which will compete against each other in a game of Tug-of-War.  Two robots will be connected by a string with a paperclip on each end.  When the referee says "start", the robots must wait (at least) 3 seconds, then start pulling.  The winner is the robot which is able to pull its opponent over the line that is initially halfway between them.

Rules:

1. No part of the robot may extend past the paperclip attached to the string.  This means that the string can't wrap around your robot.  It must be attached to a part of your robot that is facing its opponent.
2. Robots must wait 3 seconds after the referee says "start" to start pulling.  Put this delay in the program you write for your robot.
3. If any part of a robot comes off during the pulling, that robot has lost the match.  Build a sturdy structure, so your robot won't break.
4. The robot that pulls any part of its opponent over the midline is the winner.
5. Robots must have wheels, and pull their opponents by turning their wheels (you can't make a very heavy brick that the opponent has to drag)
6. The total weight of the robot must be less than 1 Kilogram (about 2.2) pounds.  Your instructor has a scale so that you may check your robot's weight.

Strategies:

• Weight - Heavier robots are harder to pull, but you must keep total weight under 1 Kilogram.
• Gears - Remember, gearing UP (connecting the drive axle gear to a larger gear, which is connected by an axle to the wheel), will increase your power.
• Traction (multiple tires) - We don't have treads available, but adding tires may help increase traction (the ability of your robot not to slip) on the ground.
•  Angle of pull -   You may find yourself at an advantage if you try to pull up on your opponents robot, causing it's wheels to lift up off the ground.  Of course, this means that you will need a tall robot, and you will need to find a way to keep it from tipping over.

If you don't know where to start, ask your instructor for directions to building a simple robot car.  You can make additions to your robot from there.