Quadcopters tend to have very poor efficency because of their high disk loading. High disk loading– that is, how much weight each square meter of area swept by the propellers must carry–is almost ...

The quadcopters that we're used to move forward, backward, left and right by varying how the torque is distributed between their four horizontal propellers. If the torque is lower on the two left-hand ...

Over the past few years, labels such as DJI have pushed drones into the mainstream. If you look closely, you'll notice that a majority of them have four propellers, while helicopters have fewer of ...