Key leads and MOI

[Isaac sur Noos]

This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
The idea is very good, one should have to produce not key to key comparison,
as when the pianist play he assimilate very quickly some sort of mental
image of the resistance of the key (static resistance ?) in regard to the
tone obtained, and he he get accustomed to it very soon.
So it may be advisable to define clearly a zone of five white notes and the
corresponding sharps , for instance C to E then F to A so the keyboard have
the same configuration in both.

Then the pianist can test more easily. what happens to the response of the
notes .


Using strong double side tape is enough for this tests. I consider doing
that myself also.


Best Regards.

Isaac OLEG
  -----Message d'origine-----
  De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de Ed
Sutton
  Envoyé : vendredi 9 janvier 2004 18:20
  À : College and University Technicians
  Objet : Keyleads and MOI


  Dear List-

  This discussion of MOI in piano actions has been one of the great moments
on this list.

  Throughout this discussion I have been trying to find an answer to the
question "How can I tell if it matters enough to do something about it?" and
"Is there a point of diminishing return where we should stop worrying about
key lead placement?"  As practicing piano technicians, this is the question
we are all seeking to answer.

  The act of playing a piano is so complex, the demands are so varied, and
the techniques, sizes and shapes of people who do the playing are so varied,
that while analysis of the physics of the action give us insight, I don't
believe it can give final answers.

  Ultimately the answers will have to come from empirical performance tests
using real musicians.

  I have been trying to think of some way to test this that doesn't require
an immense budget and research lab, since I have neither!.

  So I've done various thought experiments, looking for something feasible.

  Here's the best I can imagine so far.  I would appreciate critical
comments:

  1) Start with a piano with a well designed and regulated action.  It
should have strikeweight and frontweight continuities, even balance weight
and friction as low and even as possible, and presumably wippen assist
springs.  The keyleading should be as consistent from key to key as
possible.

  2) Add extra key leads to certain keys.  Add these leads in pairs
equidistant from the balance pin hole, one lead to the front, one to the
back.  In this way the measured parameters of frontweight and balanceweight
should not change, but the MOI of various adjacent keys would be very
different.  If, for example, one large lead is added, front and back at 8"
from the balance pin hole, the relative MOI difference between keys will
become greater from bass to high treble.

  3) Have pianists play the piano and report on what they feel and how it
influences their playing.  Compare their reports with actual locations of
extra lead.

  Thanks for your comments.

  Ed Sutton

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/caut.php/attachments/92/6d/dc/48/attachment.htm

---------------------- multipart/alternative attachment--