Nowadays, almost all UAV structures are made of carbon fiber composites. This contrasts with piloted aviation, where a large percentage of the current structure is made of aluminum and titanium, in addition to carbon fiber composites. Assembling the motor and connecting the propellers is an integral step in the drone manufacturing process. Depending on the style of the drone, the device could have more than eight motors and propellers.
Traditional drones usually have four brushless motors to improve air travel time.