Engineer Builds Pole That Balances on Four Drone Propellers for Three Hours
Aerospace engineer Peter Ryseck built a carbon fiber pole that stands on a coin-sized tip and keeps itself upright using four drone propellers. In his video, it stood for over three hours in a windy park on a single battery.
Peter Ryseck, an aerospace engineer with a master's degree from the University of Maryland, built a self-balancing carbon fiber pole that stands on a coin-sized tip and stays upright with four drone propellers. In a video posted on September 2, the pole stood for more than three hours in a windy park on one 2200 mAh three-cell battery, which still read 11.1 volts at the three-hour mark. The project shows how much drone control depends on how quickly a propeller can change its thrust.
The propellers do not lift the pole. Ryseck says almost all of its weight goes down the shaft into the ground, while the motors run just above idle and make small sideways corrections when the pole starts to tip. A push by hand makes it lean back to vertical. Ryseck also built the Mini QBiT, which DroneXL cited in June as the hobbyist ancestor of Ukraine's long-range winged FPV drones, and his website lists a flight dynamics role at Joby Aviation.
Large propellers failed
His first version, with larger motors and propellers, never balanced. Big propellers run quietly and efficiently, but their rotational inertia stops them from speeding up or slowing down within the milliseconds the controller has when the pole begins to fall. Ryseck tried 3-inch propellers before settling on 5-inch ones, the FPV racing size.
The final hardware is simple: four motors on a 3D printed mount, a Pixhawk flight controller, a Hoovo 2200 mAh 3S battery, and a carbon fiber pole from a swimming pool cleaning net, attached with a single screw.
Filtering out the 18 Hz flex
The controller is a PD loop, first tuned in a simulation. The real pole flexes, however, and flight logs showed its tilt rate concentrated around 18 Hz, while Ryseck estimates the balancing motion lies below 5 Hz. He added a low-pass filter and a dynamic notch filter that measures the pole's natural frequencies each time the system arms and filters them out. The motors keep spinning at minimum throttle, since setting idle to zero added small instabilities. The controller also slowly adjusts its estimate of vertical, so in steady wind the pole learns to lean into the breeze.
The video does not give the pole's length or total weight, the motors' idle power draw, or the strength of the wind. Ryseck does not say what the pole is for.
