When choosing a DC motor system for your specific application, several aspects have to be considered prior to deciding to choose a brushed or brushless DC motor, such as:
Required output speed/torque
Available power supply
Once these factors have been considered, the answer will be clear as to whether a brushed DC motor is suitable, or a brushless DC motor. The internal construction differs between the two and each comes with its own advantages and disadvantages.
Brushed motors from Maxon come with two options, one with Graphite Brushes and one with Precious Metal Brushes. The brushes make up the commutation system, as they make contact with the commutator bars when the rotor rotates, allowing the motor to achieve continuous motion and maintain the required torque.