Pinning on new flanges

[Isaac OLEG]

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David's

There are more than one quality, pure wool or not, and I've seen and tested
more than I desire. (Easy to,buy second grade or less quality bushing cloth,
BTW)

"traditional" bushing cloth diseappeard some time ago, while we have some
acceptable replacement none is as good in the long run to my knowledge.

Cloth for pinning from a major brand in germany is consistent, but not as
firm as wish sometime.

A Chinese customer explained me once that there is a "philosophical"
difference in the way the problems are treated : German products looking for
firmness, and resistance, while Japonese ones (or Asian) use a more
"pacific" soft way , hence kasimir mixed with nylon that is more elastic but
hold well in time.

Never used Japanese bushing cloth for repinning nowadays, if the flanges
need to be rebushed I order new ones, or I have the job done elsewhere.

Hardest problem is on old Erards where the bushing cloth is black silk, very
thin, never found an acceptable replacement for these.

Installing new action /parts in all modern designed pianos seem the best
long term solution, to me.

Isaac

-----Message d'origine-----
De : David's Email [mailto:ilvey@sbcglobal.net]
Envoyé : jeudi 26 août 2004 06:55
À : Pianotech
Objet : Re: Pinning on new flanges


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.

David Ilvedson
  ----- Original Message -----
  From: Don Mannino
  To: Pianotech
  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.

    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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