Quadcopter gears?


Elite member

I just have a quick question about the gears on some of the quadcopters I've seen.

So my question is, why is the small gear on a motor and the big gear on the propeller shaft? I would think that if the company that make the quadcopter switches the gears around, the propeller would spin at a faster RPM with less throttle, and with less throttle you would get longer flight times.
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Elite member
I don’t know for sure (I’ve wondered about it myself), but I think it’s to make it so it doesn’t overload the motor. A larger gear on the motor would make it have to work harder and in the end be even less efficient. That’s my opinion, but if anyone knows something about it I don’t please correct me.


Legendary member
Larger propellers spinning slower are more efficient than smaller ones spinning fast. For a longer flight its all about efficiencies.
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Knower of useless information
In addition, you can get a much smaller motor to do the work. Smaller motor = less weight, which means a possible higher efficiency as well.


Cardboard Boy
Those tiny coreless motors only spin at high speed, this is fine when you have a tiny prop on them but with larger quads like the Syma x5 you need to gear them down, because the motors can't spin slow enough and with enough torque to spin the props.