Matt writes; > the jacks on my 1926 Kranich&Bach have drifted on 8-10 actions. My tuner/tech suggests filing the sides down so they don't rub on the rep lever. One proper thing to do is to repin the jack, and leaving the pin long, center the jack with a considered blow to the top with a smooth, small hammer. The pin can be pushed a small amount in or out to take differing advantages of the bend. The above procedure assumes that the wood of the jack and support is not brittle; some older pieces will simply shatter, if so, carefully bend a pin, and then install with the bend away from the top of the jack, and adjust the lateral jack position with how much bend you push. Filing down the sides of the jacks will reduce the surface bearing on the knuckle, destroying function. I think that is butcher work. Ed Foote Precision Piano Works Nashville
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