The flex shaft is one of the most important and versatile tools you use at your bench. The motor brushes transfer the electricity from the power source to the inside of the motor, so it’s imperative to maintain a good connection point. Learn how to identify the signs of worn motor brushes so you know when to replace them and learn how to change them to ensure a long service life for your flex shaft.
Motor brushes typically last through at least 500 hours of operation. You should replace the brushes when they wear down to 1/4" (from their original 3/4" length). Always replace them in pairs to maintain a balanced delivery of current. If your motor demonstrates a loss of power or torque, check the brushes.
How to Change the Motor Brushes on Your Flex Shaft
1. Before performing any maintenance on your flex shaft, unplug the unit.
2. Place the unit on a flat surface.
3. The motor brushes are located behind the black 1/2"-diameter caps located on both sides of the motor.
4. Using a flat-head screwdriver, unscrew the cap, releasing the motor brush spring. Repeat for the other cap.
5. Insert the carbon end of the new brush into the motor. Press the spring in place and cover with the cap. Screw the cap back on to hold the brush in place. Hang your flex shaft and continue regular use.