This project was undertaken by three Stanford University undergraduate students - Jacob Cruz, Halsey Hoster and Jasmine Lee - during the spring of 2012 in Stanford's Visual Thinking course. Our Professional Instructors were Jessica Kessin and Catherine Luomanen. All three members were equally involved in the ideation, fabrication, and testing phases of this project.
Project Objective
The goal of this project was to create a robot that could repeatedly perform four olympic sports: the team sport, the moving sport, the distance sport, and a final sport of the team's choosing. The sports could be performed in any order, but we were only allowed to touch our robot once to start the chain of events that would allow our robot to perform all of its functions. The team sport was throwing a ball from point A to point B and then back from point B to point A after at least a few seconds of delay. Both points (A and B) had to be on the robot. The moving sport was moving the robot a total of five (5) feet in one direction. The distance sport was launching a twinkie in a parabola with a maximum height of at least five (5) feet. For our group's "free choice" sport, we decided to celebrate our olympics victories by creating a box with figures of us dancing inside of it. The box opened after all of our other sports had been completed.
In addition to these functional requirements, we were also limited in materials. Our robot had to be made entirely out of cardboard, paper, foam core, dowels, rubber bands, string, washers, tape and/or hot glue (not including decorations). The power to the various moving parts of the robot could only be provided by balls that fit on the robot (typically ping pong balls or golf balls), rubber bands, or air; no motors or other fluid substances were allowed.
Our Solution
Our main building materials were foam core and hot glue because we found that they are easy to work with as well as durable, which meant that we could test and recreate parts with comparable ease. We also used duct tape, wooden dowels, metal dowels, metal washers, string, golf balls, and rubber bands. Duct tape reinforced awkward joints well when we needed them to be extra sturdy. Wooden dowels allowed us to create small pegs, which we used many times throughout the machine. The metal dowels and washers created study axels for our wheels. String, golf balls, and rubber bands were used to, simply put, make the robot work!
We chose to do the sports in the following order: team, distance, moving, and free choice. We rolled golf balls down pegged ramps to create time gaps in between each sport and three of the sports were powered by rubber bands. Two rubber bands powered our launcher design, which we used for both the team and distance sports. The projectile rested on a thin, foam core rectangle within a larger foam core shaft. The rubber bands were then stretched backwards and held taut by a wooden peg on a foam core lever. A golf ball was then dropped onto the opposite end of the lever, which lifted the peg, released the rubber bands, and launched the projectile out of the shaft towards its target. We used the same peg-lever-golf ball design to initiate our moving and free choice sports as well. For the moving sport, we wrapped string around the front axel of our robot, tied the string to a rubber band, secured one end of this rubber band to the opposite side of the robot, stretched it out, and pegged it. When the rubber band was released, it pulled the string toward its secured end, which unrolled the string and caused our robot wheels to turn. Thus, the robot moved! For our free choice sport, or party box, we simply secured a rubber band to the front of the box and pegged the rubber band behind the box. When the golf ball hit the lever, the front of the box dropped and the three of us celebrated our olympic achievement.