3D printing is a great new technology for hobbists to create complex machines without the need for a costly workshop. We designed the airfling to be fully printable. About 90% of all parts can be printed and are assembled with well known and cheap components like screws, bolts and a threaded rod. All electronic parts are highly available.
Why did we use the Darrieus vertical wind turbine design?
A horizontal wind turbine requires large rotor blades. These blades are difficult to print on common consumer 3D printers. Due to the typical small build area of these printers, the printed rotor blades must be made of several parts. Horizontal wind turbines also require a mechanism to turn and track the rotors.
Vertical turbines don't require a wind tracking system. Their design is simple and clean. Surely, not as efficient in comparison to their horizontal friends, but enough to produce cheap and clean power. And all parts can be printed simply.
But there's one payoff: The design of the airfling EDU is not self starting. A control logic must initiate the rotation of the rotors in order for the turbine to produce energy. Since we are using standard elektro motors as generators, this can be done easily.
That's why the airfling S twists the rotors at each level. This ensures a self starting design without the need for complex twisted blades.