Defy the wind with this little wind powered car! Take an opposing force and use it's energy to move against it. This tiny car demonstrates that you can harvest the winds energy and transform it into motion directly against that very wind. :)

• Challenge Objectives
  Harness the power of the wind
  Engineering connections
  Energy transfer
  Movable assemblies

• Force Breakdown

  1. The wind cups use their large relative surface area and cone shape to harvest the wind as a force acting into the cup, creating clockwise rotation and preventing counterclockwise rotation.
  2. The wind cup shafts transfer the force to the top fitting. Their long relative length creates a larger moment and translates to higher torque.
  3. The top fitting directly transfers this torque to the first vertical shaft and "small gear".
  4. The "small gear" and "large gear" work together reversing the direction of rotation and they gear down which increases torque further.
  5. The "large gear" shaft brings the torque to the transfer gears which rotate the axis of rotation 90 degrees to the axle.
  6. Finally the axle sends the torque to the wheels bringing the winds energy to the ground resulting in forward motion.
• Revisions & Challenges
  (1/22/16) - User green_horn designed a support for the shafts to help the gears mesh. I added it to the files list but you can also find it here - http://www.thingiverse.com/thing:1284996

All of the gears were tested and revised (3) or more times to ensure solid connections. The wind cups were revised from circular to cone shaped and increased in diameter for better wind performance.
The model can be built with some dexterity and works fine to demonstrate the concept, but I believe the gears and connections could be optimized further for an easier building experience

• Concept Introduction
  This model is a great example for engineering connections and energy transfer. One possible assignment could include requiring students to estimate how many times the wind cups will rotate when the car travels a specified distance. This can be calculated after measuring the wheel and gear diameters.

The video link of it in action - http://youtu.be/eJ2HLBYwLqE

Video close up of the gears in motion - https://www.youtube.com/watch?v=m45Ot9xe7VM&feature=youtu.be