The vast majority of drones have at least four rotors for a reason. By using two sets of at least two rotors — one set turning clockwise and the other set turning counterclockwise — the drone can hover stably without spinning in place or tilting in any direction. The flight controller just needs to increase or decrease the speeds of the motors to keep the drone level. Even a helicopter-style craft needs the tail rotor to keep from spinning uncontrollably. The unique Ball Drone, on the other hand, is able to fly using just a single rotor.
This drone was built by Benjamin Prescher, and it’s one of the most unique aircraft designs we’ve seen. As the name suggests, it resembles a ball thanks to the spherical frame. That frame protects the single large propeller, the motor, electronics, and air vanes. Those air vanes are the key to this drone’s ability to stay aloft. Each of those air vanes attaches to the center of the drone via a servo motor so that they can rotate. The air vanes have guides that direct the air from the single rotor in whatever direction is necessary to maintain a stable hover. Instead of adjusting the speed of the rotors to stay level, the flight controller adjusts the angles of those air vanes.
This drone is almost entirely 3D-printed, and that includes the frame and the air vanes. Most of the electronic components are standard for a drone, including the radio receiver, LiPo battery, ESC (Electronic Speed Controller), brushless DC motor, and propeller. Instead of an off-the-shelf flight controller, Prescher designed his based of a Texas Instruments LaunchPad development board — a product we don’t see in nearly enough projects. That has a TI TMS320F280049PMS Piccolo microcontroller. As you’d expect, most of the work went into the control programming to simply keep the Ball Drone stable. But, remarkably, Prescher now has it hovering under its own power. He plans to next reduce the weight of the drone by re-engineering the frame and integrating all of the electronics into a single board.