bobble heads

Isaac OLEG oleg-i@wanadoo.fr
Wed, 16 Oct 2002 17:53:53 +0200


This is a multi-part message in MIME format.

---------------------- multipart/alternative attachment
Wim,

I remember you asked about the rep, springs, if you lightly massage the
spring after tensioning them, you stabilize them, so they stay with the same
strongness. You massage lightly the underside of the spring, that helps too
to fine tune its response.
That how it is done. The springs don't need to be too strong, but they may
respond well, the shape of their curve play a role in that.

To have a spring stronger, you can bend it, but if you pull straight on the
extremity of the string with your hook you will stiffen the coils more
durably (and faster) . The hook part of the spring tend to deform while
doing it, so I turn my tool so the spring disengage from the tool before its
too much deformed.

You will see that on some pianos someone have done that yet in the factory,
and the hooked extremity of the spring is yet opened.

I was shown recently how to un bend the springs if someone put a kink in it,
that is why the "S" shape of the Yamaha spring tool is so efficient, you can
straighten a kink with it (not with the Hart tool)/

Best.

Regards.

Isaac OLEG
  -----Message d'origine-----
  De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de Isaac
OLEG
  Envoye : mercredi 16 octobre 2002 15:12
  A : College and University Technicians
  Objet : RE: bobble heads


  Hello,

  Possibly because of the new knuckle position the jack is not clearing it
or is locked in the little cushion in the lever window.

  Bad action stack may be , check by lifting one side of the keyboard and
see if the action warps a lot or if the drop screws are not aligned.

  Warped action stack and  bad frame bedding could well add to the thing

  Hammer tail too short, backchecks angle , and so on .... too much dip
  Isaac OLEG

    -----Message d'origine-----
    De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de
Wimblees@aol.com
    Envoye : mercredi 16 octobre 2002 00:47
    A : Pianotech@PTG.org; caut@ptg.org
    Objet : bobble heads


    Problem: Bobbling hammers on a S&S M from C5 on down. I mean, they don't
even check on a hard blow.  Some of them are checking, but only on a hard
blow. The rest just bobble. New hammers, shanks and flanges.

    Let off is right, drop is right, there is after touch. I changed let
off, I changed drop.  Keys are level, right amount of dip.  I increased dip,
decreased dip. I've increased rep spring, and decreased rep spring. Dampers
are not in the way. Nothing.

    This is a 1939 model. There has been some discussion about knuckle size.
As I said, these are relatively, (about 3 years old) new h/s/f/ , with 3/8"
knuckles. Could that have an effect?

    Wim

---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/caut.php/attachments/b1/15/cb/da/attachment.htm

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


This PTG archive page provided courtesy of Moy Piano Service, LLC