jack slides out before delivering power

[Joe And Penny Goss]

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Julia,
Just a quick thought, sometimes it appears that the jack is going back =
under the hammer butt and even when the jack is pushed with a screw =
driver to check for further travel, it will go no further.  When in fact =
the jack should go back further but is being stopped by too thick a felt =
due to using too thick a square of felt when replacing a lost felt.Check =
the distance the other jacks that work are moving.Sorry for the =
disjointed thoughts in a hurry to get on the road.  <G>
Joe Goss RPT
Mother Goose Tools
imatunr@srvinet.com
www.mothergoosetools.com
  ----- Original Message -----=20
  From: David Skolnik=20
  To: Pianotech=20
  Sent: Tuesday, November 23, 2004 9:17 AM
  Subject: Re: jack slides out before delivering power


  Julia -

  Your description of the symptoms remains a bit unclear.  Do you mean =
that if you were to sit down at the piano and play each note forcefully, =
once, that each would play, but if you were to do the same with a =
minimal force, it would not?  Or is it that a note, after being played =
softly once, will cheat when attempted again?   While Issac and David =
Stahl might be correct in assessing the jack pinning as the problem, it =
could also relate to key leveling, though the opposite to what you =
suggested.    If there is not enough (just enough) lost motion, the jack =
will not return under the butt on a slow (soft) release. Besides =
leveling, other possible contributing keyboard issues could be either =
excess friction or excess front weighting.  This could be further =
aggravated by tight wippin pinning, excess friction between jack top and =
butt leather, bad geometry of the butt profile,  incorrect thickness of =
butt cushion, or an imbalance between hammer return spring and jack =
spring.  =20

  I recall working on a small Steinway consol, some years ago, where the =
configuration of the lower butt geometry created the dilemma where, by =
the time I eliminated excess lost motion, the jack would not navigate =
over what appeared (to it) as an inverted speed bump.

  On the other hand, it might just be the jack pinning.

  Let us know.

  David Skolnik



  At 11:52 PM 11/22/2004 -0500, you wrote:

    Greetings,=20

                 Working on a Hamilton built by Baldwin studio upright =
today, I noticed that  on a reallly soft blow to the key, the jack wants =
to slip forward almost to the back of the catch's shank, instead of =
delivering the kick to the base of the hammer butt.

                 The customer complained that, on a soft blow the key =
wouldn't play and would sort of jam. Looking at this situation I saw =
that the jack would sometimes just slip out too much forward and not =
deliver its power. What would cause this? Could the keys not be levelled =
high enough?

    Julia Gottchall,
    Reading PA  
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