Pianotech

  • 1.  Mason & Hamlin A 1914 Key Shoes

    Member
    Posted 01-06-2023 01:18
    I am working on a Mason & Hamlin A trying to get it to regulate. There is no after touch at all although I was finally able to get some on 5 randomly chosen notes where I removed some of the front key punchings which appear to be the originals judging from their color and crumbling condition. It is apparent that the key buttons where replaced and that new key shoes where installed. Because the shoes are about 1/8" thick there is only a felt and one thin paper punching on the balance pin. Although it is more work to mortise in a key plate rather than glue on a shoe I am wondering if the long shoe affects regulation. It is a rather long shoe as well and I wonder how one determines the proper length of a shoe. I read a T&T from a past journal that a key plate with a stack of bushings is the better repair According to the Piano Action  Handbook keyheight for a Model A is 2 19/32 measured on the underside of the keyfront. I got 60mm or 2 23/64 or 61mm = 2 13/32 depending on the ruler/eye alignment measured to the keytop Hammer blow should be 1 3/4" ; let off  1/16" and key dip = .390"  backcheck distance 1/2" . My plan is to try to achieve these dimensions and use new paperand cardboard  punchings as well including crescendo front felt punchings. the 5 keys I was able to get after touch on made me feel I was heading in the right direction. I am open to any suggestions about other things I should do or measure. All of the hammer shanks, flanges and whippens are original but hammer felts where replaced in 1989 as well as the out of round now knuckles

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 2.  RE: Mason & Hamlin A 1914 Key Shoes

    Registered Piano Technician
    Posted 01-06-2023 01:43
    James.

    You have two choices. Raise the keys to 19/32, or increase key dip. by .05