> I don't recall Steinway (half-round) balance rail bearings being > discussed on the lists anytime recently. > > What is the minimum thickness of paper punchings that should be put > under the bearings to promote quiet operation? Don't know. I like at least 0.010". > What are the arguments against these bearings -- besides the fact that > they can be noisy, make the use of Rawson leveling tabs problematic, and > make it difficult for Stanwood installers to tweak the key ratio with > veneer shims? > > Kent Swafford Other than being potentially noisy, I don't have anything against them other than they take up space that a key stiffening shoe might otherwise occupy. The folks using half punchings are just doing what the half dowel already does - keeping the pivot point close to the same spot throughout the key stroke, where with a flat punching, it moves at least half the width of the punching during the stroke. My take. Ron N
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