Outrunner

The term outrunner refers to a type of brushless motor primarily used in electrically propelled, radio-controlled model aircraft.

This type of motor spins its outer shell around its windings, much like motors found in ordinary CD-ROM computer drives. In fact, CD-ROM motors are frequently rewound into brushless outrunner motors for small park flyer aircraft. Parts to aid in converting CD-ROM motors to aircraft use are commercially available.