Downbearing question >> crowned or flat rib board

[Isaac OLEG]

This is a multi-part message in MIME format.

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

Hello David,

If memory serves he wrote about the use of trigonometry to compute a
vertical composite of down bearing pressure in pounds, using the 2 lengths
of the string, I remember asking myself why too.

May be because it is easy to measure the height towards the capo with a
thread, but difficult to measure this way with aggrafes because of the plate
bars in the way ?

I understand recently that we probably don't have to apply downbearing the
same way on a rib crowned soundboard and on a "compression crowned" board,
as the last one will do it's best under a light load, while the crowned rib
bar ask for the downbearing to give them some more internal tension.

That makes a big difference in approach I guess.
A friend of mine use to fine regulate downbearing pressure with the string's
rest height while stringing, checking with the strings at pitch as he goes.

Do some of you apply this method ?

Any thoughts about that ?

Bests
Isaac OLEG

Entretien et reparation de pianos.

PianoTech
17 rue de Choisy
94400 VITRY sur SEINE
FRANCE
tel : 033 01 47 18 06 98
fax : 033 01 47 18 06 90
cell: 06 60 42 58 77

  -----Message d'origine-----
  De : pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]De la
part de David Love
  Envoye : samedi 1 fevrier 2003 16:34
  A : Pianotech
  Objet : Re: Downbearing question


  June 1988, page 34, right hand column, first paragraph says "...A test
string (carpet thread), although limited to the capo bar sections...), and
the second paragraph starts:  "The carpet thread can't be used where
agraffes exist so another approach is necessary..).

  This is in reference to setting downbearing by using the deflection angle
to calculate the distance over the rear string rests when the string is just
touching the bridge top.

  David Love
  davidlovepianos@earthlink.net


    ----- Original Message -----
    From: David Skolnik
    To: Pianotech;davidlovepianos@earthlink.net
    Sent: 2/1/2003 3:02:56 AM
    Subject: Re: Downbearing question


    David -
    Can you indicate the issue of the Journal or other source where this
article is to be found?

    David Skolnik
    davidskolnk@optonline.net



    At 11:43 PM 1/31/2003, you wrote:


      So I'm reviewing my method of setting downbearing and I'm reading this
article by Nick Gravagne.  He says that although you can use a thread test
to set bearing in the capo section, it won't work in the agraffe section and
I'm wondering why.  The answer is not coming immediately to mind.  I must be
overlooking something obvious.  Explanations?  Thanks


      David Love
      davidlovepianos@earthlink.net

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/ee/ef/2d/94/attachment.htm

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