The end cap for steel tubes is because as long as the brush piece has a business trip, it will affect the quality of the motor. If the brush is too high, it will hit the varistor; if it is too low, it will hit the white washer; (see the rotor) if it is too short, it will not hit the rotor. This will make the rotor unable to operate; the bifurcation of the brush will make the current unstable; of course, it can not bend, it will make the current abnormal. What needs to be added is: the brush piece of the end cap is very crisp and tender, and a little carelessness will cause the brush to branch or bend, so be careful!
