Manned Electric Helicopter With 7 Tail Rotors

One of the best things to come from the growing drone industry is the development of compact and powerful brushless motors. We’ve seen several multi-rotors capable of carrying a human, but electric helicopters are rare. [OskarRDA] decided to experiment with this, converting his single-seat ultralight helicopter to electric power and giving it seven tail rotors in the process. Flight footage after the break.

The helicopter in question started life as a Mosquito Air, a bare-bones kit helicopter originally powered by a two-stroke engine. The engine and gearbox were replaced with an EMRAX 228 109 kW brushless motor. Initially, he used the conventional drive-shaft powered tail rotor but wanted to experiment with multiple smaller rotors powered by separate motors, which has several advantages. He only really needed four of the 5008 or 5010 size motors with 18″ props to get comparable thrust, but he added more for redundancy. The new setup was also lighter, even with its independent batteries, at 7.5 kg compared to the 8.1 kg of the old tail rotor assembly.

One of the major advantages of a conventional helicopter over a multirotor is the ability to autorotate safely to the ground if the engine fails. A coupled tail rotor bleeds some energy from the main rotor while autorotating, but since the tail rotor has independent power in this case, it allows all the energy to be used by the main rotor, theoretically decreasing decent speed by 120 feet per second. [OskarRDA] did some engine failure and autorotation test flights, and the results were positive. He likes his new tail rotors enough that he doesn’t plan on going back to a single large rotor.

Power for the main motor is provided by a 7.8 kWh, 40 kg LiPo battery pack mounted beneath the seat. Theoretically, this would allow flight times of up to 27 minutes, but [OskarRDA] has kept most of his flights to 10 minutes or less. He didn’t add any electronic gyro for stabilization, but he did add some electronic coupling between the main motor and tail motors, to reduce the torque correction required by the pilot. Even so, it is clear from the flight footage that [OskarRDA] is a skilled helicopter pilot. Continue reading “Manned Electric Helicopter With 7 Tail Rotors”

Being Picked Up By A Swarm Of Drones May Become Reality

In case you haven’t seen it yet, this video has been taking the internet by storm. The YouTube user [Gasturbine101] has successfully taken flight in his home made multi-rotor flying machine.

It’s a massive array of high powered brushless motors with props, fifty-four in fact, all counter-rotating. It has a weight of 148kg (we assume this includes the inventor), and produces a maximum lift of 164kg. Apparently it’ll even last for about 10 minutes. The props are grouped into six, using Hobbyking stabilizers to balance the flight.

He calls it the Swarm.

Continue reading “Being Picked Up By A Swarm Of Drones May Become Reality”