chatenever

What's the advantage of running a large propeller at a relatively lower rpm (using a gearbox or an outrunner motor) as compared to using a higher rpm small propeller, with the pitch selected to draw the same watts as the larger, slower prop?

Matt Kirsch

My Feedback: (21)

To oversimplify, there are two factors to which you can allocate power in an airplane: Thrust, and speed. A larger prop spinning at a slower RPM produces more thrust and less speed, while a smaller prop spinning faster produces more speed and less thrust. The key to electrics is matching the thrust and speed needs for the airplane. This way you can get the flying qualities you desire for the least weight and least cost.