Brushed vs Brushless RC Motors
If you’re new to the RC hobby then you’ve probably heard two terms thrown around in regards to the motors used in RC cars and trucks, Brushed and Brushless. Back in the day RC car enthusiasts had no choice but to use brushed motors. They weren’t as terrible as people today make them out to be but compared to brushless motors they are inferior in most ways. Not only are brushless motors relatively maintenance free, they are also more efficient meaning they make more power with all other things being equal. The only slight downside to using brushless motors is that, unlike brushed motors, they can be negatively affected by water. Even that is becoming less of a concern as manufacturers like Traxxas and Orion release their totally waterproof brushless systems.
Brushed motors use two magnets mounted inside the motor housing which face a spinning armature. The armature has a set of wires wound around it, which when electricity flows through them, a magnetic field is created ultimately pushing the coils away from the magnets. This effect causes the motor to spin. The electricity flows through brushes which come in contact with the armature on a surface known as the commutator. As the armature spins the electricity flows in one direction and then to other to keep the motor spinning. The number of times the wire is wrapped around the armature is what dictates the amount of torque and rpm the motor will create. That is why you’ll notice that rock crawlers which need a lot of torque will use 55 turn motors, while high speed touring cars might use 6 turn motors. The problem with brushed motors is that, since the brushes contact a spinning commutator, they wear out. The rate which is wear depends on the number of turns the motor has, the voltage your battery puts out, the size of the vehicle and temperature. While changing motor brushes isn’t that big of a deal, most hobbyists are glad to see them go.
Brushless motors are sorta like brushed motors turned inside out. In a brushless motor the coils are permanently mounted to the motor housing while the magnets are attached to the rotor. As the rotor spins a speed control decides which coil to energize to keep the motor spinning. RC brushless motors are available in sensored and sensorless versions. In the sensored variety a small sensor tells the speed control where your motor’s rotor is in relation to the magnets. The only thing you really need to know is that sensored systems are a little smoother while also being more complicated.
Brushed vs Brushless:
Now that you have a better idea how each of these motors work you may still be asking yourself which is better. Well that is easy. Brushed motors are cheaper but in the RC car world they are a dying breed. If you can afford a brushless system then by all means go for it. They create motor power and are virtually maintenance free.