Much More Comm polishing set
For those racers that don’t use brushless motors, Much More have released this handy Comm polisher set. It comes with an aluminium dial and a polishing stick and it works by simply removing the brush and inserting the stick. You then mount the dial on the end of the shaft, and lock it in place with its grubscrew, and rotate the dial counter clockwise 10 times and the polishing stick will have the comm polished like new. No need to remove the commutator from the motor or have an expensive comm lathe. The stick is available in both medium and hard versions.
Source: Much More [much-more.co.kr]