Brushless Motors

Brushless motors are one type of motor commonly found in Antweights. Originally designed for model aeroplanes, in Antweights they are used for spinning disks and other weaponry, whereas the other type of motor (brushed) are used for the robots main drive system.

Brushless motors are generally more powerful for their weight than brushed motors but require a brushless speed controller in addition to a power source. Unlike a brushed motor, simply connecting up the wires to a battery will not result in the motor turning. They can also be more expensive than brushed equivalents.

As their name suggests, these motors don't have physical contacts (brushes) which is why a special speed controller is needed.

http://www.robotwars101.org/phpBB/viewtopic.php?t=1251 - a topic on RW101 discussing good brushless motors.