The CFS (Control Finishing System) main function is to slow the pad rotation down so that when the pad meets the work piece, it doesn't gouge. The pad rotation out of the box will be around 400-800 rpm. The pad rotation will slow when the pad touches the work piece and speed back up when removed.
Visually, if the pad is rotating at 400-800 rpm, you can still see/count the rotations of the pad. When the brake (CFS) wears to the point it is no longer doing its job, the pad rotates at the spindle speed, which is 12,000 rpm or so, and is very hard to count or see individual rotations. Functionally, if the unit is gouging or taking off when it touches the work piece (because of rapid slowing from 12,000 pad speed to a few hundred rpm) the brake is not doing its job and should be replaced.
Figure F is the CFS disc
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