If you have not done so, you should advance the brush timing a bit from the stock position. They start turning a little blue and you know you are pushing the edge. Watch the color of the copper braids on the brushes instead. In the 8 seconds of a drag race, you really don't learn much measuring brush temps. Gets the motor all dirty with brush dust, and gets masking tape residue on the comm, however. The classic method is to wrap the comm with sandpaper, put in the brushes, and turn the motor by hand until the brushes show a curve all the way across. I just clamp each brush in the vice and saw off a thin slice of the end with the hole saw. Use a hole saw in a drill press or milling machine the same diameter of the comm in If you are in a rush, you can stone the comm, pull a brush to see if it is seated all the way across, then repeat until the brushes are all seated ~90% across. Don't inhale the dust.Īny time you replace brushes, you should stone the comm, and seat the brushes with a run in. After you have run in the brushes, thoroughly blow out all the brush dust.
![eletric motor drag racing eletric motor drag racing](https://images.hgmsites.net/med/chevrolet-camaro_100690373_m.jpg)
An ordinary 12 volt auto charger will go up in smoke, even if it is labeled for 50 amp capacity. A 12 volt RV power supply & battery charger works well. You will need a big power supply to do this as it takes about 30 amps to spin each of these motors. Run the motors on the bench for a "week" on 6 to 12 volts. Seating the brushes conforms the brushes to fit the curvature of the commutator increasing the surface area of the brush.
![eletric motor drag racing eletric motor drag racing](https://s1.cdn.autoevolution.com/images/news/2800-hp-all-mustang-all-electric-drag-race-sounds-like-the-future-160167-7.jpg)
Running in the motor (Seating the brushes)īefore installing a new motor, it's a good idea to break it in or run it in to seat the new brushes.
![eletric motor drag racing eletric motor drag racing](https://cdn.motor1.com/images/mgl/Wx31q/s3/hyperpower-ev-dragster.jpg)
They are most definitely the weak link in the chain of conductors within the motor.ĭouble up the brush "shunt" wires, or replace them with larger gauge wire. Stock brush shunt wires last to about 1200 amps and may take up to 1400 amp. You can purchase comm stones from McMaster-Carr at: The access to the commutator is a bit limited, so you need a stone that is at most 1/2 inch thick. The exhaust from the shop vac is quite warm from cooling its own motor.)Ī clean commutator will prevent arcing and extend brush life. Pull air through the motor vents with a shop vac. The biggest single thing you can do to help with motor survival is to cool the motors well between runs.