1. J.M. Gabrielse VEX Center of Gravity J.M. Gabrielse

2. Center of Gravity The center of gravity is the average mass and position of all the pieces that make up a robot.

3. J.M. Gabrielse Robots tip over all the time! Build your robot so the center of gravity stays between the wheel axles and your robot won’t tip over.

4. J.M. Gabrielse Find the Center of Gravity Hang any object from a string: The object will rotate until the center of gravity lines up with the string. Hang the robot from a string and mark the line. Tie the string to a different points and repeat. The center of gravity is where the lines cross.

5. J.M. Gabrielse

8. The Center of Gravity Is Where the Lines Cross

9. J.M. Gabrielse Tipping Robots tip if the center of gravity isn’t between the wheels.

10. J.M. Gabrielse Robot Arm Pick something up and the center of gravity moves

11. J.M. Gabrielse Robot Tips Keep heavy items: close to the ground in the middle of the robot The protobot’s battery and arm balance each other out to keep the center of gravity in the center of the robot.

12. J.M. Gabrielse Your Turn Where is the center of gravity? What happens to a robot if the center of gravity isn’t between the wheels? How can you make a robot less tippy?

13. J.M. Gabrielse Resources Inventor’s Guide: 2·7 - 2·11

14. J.M. Gabrielse Resources http://www.education.rec.ri.cmu.edu/roboti cscurriculum/vex_online/lessons/mechanic s/center_of_mass/mechanics_center_of_ mass.htmlhttp://www.education.rec.ri.cmu.edu/roboti cscurriculum/vex_online/lessons/mechanic s/center_of_mass/mechanics_center_of_ mass.html Inventor’s Guide: 2·7 - 2·11