A basic quadcopter drone is very simple — mechanically at least. There are four motors with props mounted, and when they spin real fast the drone flies. There are, of course, sensors and fairly complex calculations going on to keep the drone flying in a stable, predictable way. But, really, it’s just four powerful fans that keep the drone aloft. Over on the YouTube channel FliteTest they wanted to push that to the extreme and see if they could literally make box fans fly.
The FliteTest team was inspired to build their box fan drone after seeing a viral image of a drone made from desktop oscillating fans. That image is obviously a joke, and the “drone” in the photo definitely couldn’t fly. But, that doesn’t mean it’s not technically possible to make fans fly with some modifications. To start, they purchased four new box fans, like the kind you’d use to keep your garage or workshop cool.
Each fan has a motor and fan blade inside, but both needed to be replaced. The fan blade was too flimsy, and was designed for moving a lot of air at low RPMs. The motor was also designed for low RPMs, and not the fast rotation required for a drone. They replaced those with more conventional brushless DC motors and props, which were paired with a standard flight controller. Sure, all that was left of the actual fans were the housings, but it flies!