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After 25 plus years in the business, most shops don't know what they're doing when turning rotors or drums. It's all in the setup and keeping the mating surfaces and lathe parts clean. Most guys just toss the rotors on and let the machine go at it. They usually end up taking a good rotors and making it wobbly.

If you don't currently have a pulsating pedal, just scrub the friction surfaces with some 80 grit to remove residue from the old frictions and reassemble.