A Huge Drone Designed to Carry an Incredible 100kg Payload

Have you ever seen a Chinook helicopter carrying a huge load, like multiple Humvees? If that is possible, then why can’t an electric drone carry a similarly impressive amount of weight? The simplest answer is that fossil fuels have much greater energy density than electric batteries. That has been a challenge for Simon Sörensen, of the RCLifeOn YouTube channel, in his quest to build a heavy-lift drone. Getting enough power to the motors is not a trivial undertaking, but Sörensen managed to get his 100kg-lifting drone flying in his most recent video.

The problem of power vs. weight is one that affects all vehicles, but is especially important for aircraft. If you want your drone to carry more weight, you need to give it more powerful motors capable of producing more thrust. But those will require more power, which means bigger and heavier batteries — negating the additional thrust or reducing flight time.

There isn’t much that Sörensen can do about the energy density of the batteries. He’s using lithium-polymer batteries, which already have some of the best energy density available in consumer batteries. Therefore, he had to reduce weight in other ways in order to increase his drone’s payload capacity.

Size is, of course, important and this drone is huge — 3.5 meters in diameter, including the propellers. But it is surprisingly light, despite its size. The frame is made of lightweight aluminum extrusion arms on a central wood base. With the frame, motors, propellers, and batteries, it weighs in at about 20kg. However, the motors and propellers will theoretically be able to generate 160kg of total thrust at max capacity. That can be a little misleading as drones need some headroom for ascending, maneuvering, and keeping themselves stable. But that is still a very impressive power:weight ratio.

Sörensen has a ton of experience building and tuning drones, but this one proved to be a headache. The drone has a Pixhawk flight controller and though those are usually reliable, Sörensen had trouble with it from the beginning. That turned out to be an issue with the radio receiver and replacing it with a different model solved that issue.

Even so, Sörensen struggled to tune the drone’s PID settings and achieve stable flight. By the end of the video, it was flying… kind of. It was still pretty erratic, even after stiffening the frame to reduce flex.

However, the results are already promising. In a follow-up video, Sörensen will hopefully have the drone flying better and will move on to the heavy-lifting (literally).