Chopper Drones has 4 Rotors, But Not Real Helicopters. Why?
![DJI Mavic Pro drone 2017-03](i/DJI_Mavic_Pro_drone_2017-03.jpg)
4-rotor copter is simpler and better stability. I suppose real helicopters don't because to save parking space??
Basically:
- Big blades is more efficient than multiple smaller ones.
- Electric motor can change speed fast. But combustion engines cannot.
- Single combustion engine is more practical and efficient than 4 smaller combustion engines.
- Real helicopters cannot use eletric for motor, because they are not efficient enough yet. Battery too heavy, and don't last long.