Eli5 why do drones have four blades and helicopters only have one?

Question

Eli5 why do drones have four blades and helicopters only have one?

In: 2

Answer 1

Well, some problems are that it would need to be massive and it would require more space to land, and it would be much more complicated

It would require more parts, and additional transmissions or driveshafts or engines or something, which would add mechanical complexity, weight, and maintenance time and upkeep cost. More parts means more parts that can break. Drones are plastic and cheap in comparison, so it doesn’t matter.

There was a soviet concept called the Mil Mi-32 that where they planned to make it a giant triangle with 3 rotors, it’s hilarious, type ‘Mil Mi-32’ into google images

I think the soviets figured the extra rotors would also have resonance problems and vibrate weirdly