Basic drones are very affordable these days—you can literally find some for less than the cost of a fast food drive-thru meal. But that doesn’t mean drones are easy to control. That is actually quite difficult, but manufacturers are able to work off of established reference designs. In a video that perfectly illustrates the difficulty, The Tinkering Techie attempted to make a supercapacitor-powered drone with his own custom flight controller. 

Most airplane designs have inherent aerodynamic stability. Even without power, they can continue to glide. Even helicopters have some inherent stability in the form of autorotation. Quadrotor drones do not—they need constant power and very frequent motor control updates just to stay aloft. Even the slightest control error will result in catastrophic failure. Despite knowing the challenge, The Tinkering Techie wanted to try making his own flight controller.

Aside from the custom flight controller, this drone is also unique for its power storage. Instead of conventional lithium batteries, it has a bank of supercapacitors. Those can fully charge in seconds—though they don’t store energy well over long periods of time. 

The job of the flight controller is directing power from the supercapacitors to the motors (brushed DC motors, in this case) in a very precise manner. An Arduino Nano 33 IoT board oversees that process and The Tinkering Techie chose it because it has onboard sensors useful for a quadcopter, including a gyroscope and an accelerometer. A custom PCB hosts the Arduino and the supercapacitors, while a simple 3D-printed frame ties everything together.

Unfortunately, this isn’t a success story and The Tinker Techie ultimately failed to achieve stable flight. The are many potential reasons for that, but one of the most glaring was the use of brushed DC motors, which can’t respond as fast as brushless DC motors can — an important factor for a drone.