Is it possible to build an ultralight helicopter with electric motors as its main engines? So I'm trying to make an electric ultralight helicopter, but I'm not sure if it will work. Is it possible to use electric motors to make it fly? If yes, I'm going to need some advice.
I'm expecting the aircraft to be able to lift a 200kg load, with the maximum rotor blade diameter of 7m in coaxial rotor configuration.
From a quick Google search, you can find that Sikorsky Firefly and Tier One R44 are two examples of eHelos, conventional helicopters converted to electric propulsion. They both fly around 20-30 minutes (though the Firefly never flew).
As for building an electric helicopter, I believe off-the-shelf components (such as Tesla motors and batteries, available from parts breakers) have enough performance for an eHelo. The actual configuration of the aircraft (single main, coaxial, multicopter etc.) depends on the manufacturer's expertise on rotor blade hubs and/or distributed electric propulsion. So unless you work for Kamov, a coaxial rotor hub will be prohibitively complex (thus expensive) for a prototype ultralight helicopter.