Jack popped out

[TOM DRISCOLL]

Julia,
    This can happen in a vertical action due to one or more regulation  problems.My guess is that the hammer is being caught about  an inch from the string.
    The quick and easy test is to adjust checking closer to the string. Shortening the checking changes the angle of the butt when caught and allows the jack move freely until the key stroke ends.    Don't forget the other regulation specs.Key dip ,blow and  letoff --THEN adjust backchecks.
    Also, too tight bridles can bind the jack .Some  Baldwins have a design that can allow the tab on the strap to slide down the bridle wire and lock the whippen and butt assemblies together.
    Tom Driscoll RPT
    P.S.
    Actions with an adjustable rail to limit movement of the jack away from the butt eliminate this problem and improve repetition by keeping the top of the jack closer to "home"
  ----- Original Message ----- 
  From: KeyKat88 at aol.com 
  To: pianotech at ptg.org 
  Sent: Thursday, May 04, 2006 8:36 PM
  Subject: Jack popped out


  Greetings, 

          I had a customer call about a key that would not play. When I got there and looked, at it the jack had flipped out from under the butt and was 'stuck' I simply lifted the hammer and pushed the jack back under. Then I asked if she was doing some loud hefty playing, as in Beethoven when it happened, and she said "Yes!...That's exactly what I was playing, Beethoven!".

         My question is should this even happen at all? The key was regulated ok, no excessive space between jack and butt on a normal blow.  I have seen pianos that were moved and tilted in such a way that the jacks popped foreward, but very few while playing that this happened. It is a Baldwin/Hamilton console from the 60's 70's era; a nice work horse of a piano.   

  Julia Gottshall
  Reading, PA
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