What is an outrunner engine? Also, how does this relate to other engine choices and when they might be used?

Thanks in advance.

An outrunner motor is a variety of brushless motor. The design is, in effect, turned inside-out with the windings stationary and the magnets rotating with the casing of the motor. May offer more torque and thus eliminate the need for a gearbox in some installations.

Dave has it right. The outside of the motor does turn instead of the inside. Go to Hobby Lobby's web site and check out their AXI (brushless motors) adds. They give you an idea of that these things can do.

They do have tons of torque for their size. As a very loose idea, AXI motors will fly about a pound of plane per ounce of motor. I have the AXI 2808 (3 oz) on a 32 oz plane and it will haul that thing around like crazy. The motor is capable of flying a 54 oz plane, but that would not be a very aerobatic situation. In fact, the plane (32 oz, 48" WS) I have it on recommends, and came with, a speed 500 motor with gear box; my AXI motor, speed controller, and battery pack (3S 2000 mAh LiPo) weigh less than the canned 500 with the gearbox. They are great little motors. And efficient, I can get a 23 minute flight with that setup.

Tom

Harleyflyer: An engine is a reciprocating engine a motor is an electic motor, big diffrence. Bob

List of outrunner manufacturers (kits too), meanwhile there are more than 60!:

Build your own high-torque/high-performance outrunners



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