Pinning on new flanges

[David's Email]

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If we have to go back to the times of poor bushing cloth...yes that is a =
factor.  I'm not even sure poor quality bushing cloth can be bought =
anymore?   Don, with all your expertice, if you have a preference in =
bushing cloth and have reservations about some on the market...PLEASE =
let me know...privately if need be.  =20

David Ilvedson
  ----- Original Message -----=20
  From: Don Mannino=20
  To: Pianotech=20
  Sent: Wednesday, August 25, 2004 7:11 PM
  Subject: Re: Pinning on new flanges


  At 01:38 PM 8/25/2004, you wrote:

    If you have a hammer swinging 4 to 7 times and it has side play you =
have a birdseye problem...not the bushing.
    =20
    David I.

  Well, David, there is also the quality (or lack thereof) of the =
bushing cloth.

  As many here know, I have done a bit of study into action centers, =
especially grand hammer centers, both on my own and through work with a =
company I worked for in the past. Even and 'correct' friction became an =
obsession when I was rebuilding pianos during the 80s.

  At that time a piano dealer I did work for was having me "maximize" a =
certain brand of American pianos, which at the time was using seriously =
substandard action cloth and / or cloth sizing procedures.  One of the =
steps I took in customizing these actions was to do a very heavy =
shrink-fitting of the hammer shank centers.  Short of rebushing the =
shanks, this was the best way I found to improve the fit of the centers. =
 The centers (which came with 19.5 pins as I recall) became extremely =
loose, after which I burnished and fitted 20.5 pins into the now thinner =
bushings.

  The change in touch and tone from this one change to the piano was =
incredible.  It was not subtle at all - the pianos sounded dramatically =
more solid in tone and more powerful.  Of course, I had to re-weigh off =
the keyboards, as the weights had been installed with horribly uneven =
friction levels in the actions.  Hammer flange friction varied from 2 to =
10 grams in almost every set I worked on.

  The bushing quality is the big variable in fitting action centers, and =
is one reason people will disagree so strongly on what friction is =
correct.  Their experience with different pianos causes different =
opinions to be developed.

  When repinning hammer centers, I have always pinned for even friction =
through the set.  I strive for +- 1/2 gram within a set (a 1 gram =
tolerance - which I would prefer to be 0, of course), and the amount of =
friction is decided on according to the ambient temperature and =
humidity, and the relative firmness of the action center cloth.  4 - 6 =
grams is a guideline, but I frequently pin parts with very high quality =
felt at 2 grams, especially in dry conditions.

  If the cloth is firm, it can be pinned more loosely and still control =
the hammer motion well.  If the cloth is soft, you must pin it tighter =
in order to maintain the control.  I do not have a formula to decide how =
tight - it comes from feeling the side play after pinning, and the =
experience of checking this on many pianos.

  As for tonal change from very tight centers, the best illustration I =
have had was with one unfortunate piano in which the hammer centers were =
all gummed up.  The usual problem of the owner not wanting to pay for =
new parts was there, so with a written disclaimer signed by the =
customer, I agreed to clean and lube the action to keep it working until =
the parts could be replaced.  The tonal change was absolutely dramatic - =
the customer said afterwards "I didn't know you were going to make the =
tone better, too!"  With sluggish centers the tone was dull and muffled =
with very, very poor sustain.  After freeing up the centers the tone was =
moderately bright with very good sustain.

  I am also fond of the later version of the Teflon bushings, by the =
way, but this is long enough for now.

  Don Mannino RPT


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