Abstract: An apparatus for micro-finishing a brake drum braking surface. The invention uses a center of rotation gaged from the unfinished braking surface to properly position the brake drum on the apparatus and position a shoe for engagement with the braking surface A film, having an abrasive surface, is routed over the shoe so that the abrasive surface will contact the braking surface. The brake drum is rotated and the film is urged into contact with the braking surface while the film and the shoe are axially oscillated along the rotational axis of the brake drum. In mounting the brake drum on the micro-finishing apparatus, a mechanism is provided for simulating the mounting forces normally incurred by the brake drum during use.

Abstract: A universal crankshaft pin and main bearing finishing machine having one pair of pin and main bearing arms with finishing shoes simultaneously engageable with one pair of pin and main bearings. A programmable controller and encoders automatically monitor drives which position and oscillate the arms over the width of the bearings for each pair of pin and main bearings until all required bearings of the crankshaft are finished. Adjustment and automatic programs are provided for different crankshafts which may vary in length, number of cylinders, stroke, axial location and width of bearings.