But why are they 'unacceptable' and to whom? How old is the action? What has been done to it in the past. Wippen pinning is not critical as long as they swing freely. Jacks must move freely. Wippen post MUST have some friction or spring will be too weak. Hammers are the major source of 'felt' friction. (perceived that is) Hammer swing can be tested by: Carefully swing and pin one every 8th to 10th hammer. Lean the action against a wall at such an angle that the previous set samples just barely move back when moved 'lifted' away from the wippens. Those that move slower are tighter, those that move faster are looser. Wippen pinning can be checked the same way but the stack has to be off the keys. 'Unacceptable' friction can also be caused by key bushings, unpolished key pins, unpolished capstans or glazed or worm knuckles. Testing is done without dampers. Newton
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