[pianotech] string scale

[David Love]

It's pretty hard to move the bridges without replacing the soundboard.
However you can alter the speaking lengths some in the process of recapping
them.  Small changes to the speaking lengths in the capo section can make a
significant difference in the tension and allow you to make corrections up
there to smooth out the curve or raise weak tensions in the upper part of
the piano (see my cautionary note below).  Through the tenor section you
will mostly only be able to play with the gauge choices and transitions.
Even in the low tenor where tenor/bass break problems are frequent you won't
be able to do too much without moving the bridges but sometimes a change
from plain wire trichord to wrapped bichord or wrapped trichord can improve
things some.  The bass sections often can be improved from the original even
with the original speaking lengths unaltered.  

So even without moving the bridges much can be accomplished by a careful
reexamination of the scale even without the original data.  The original
data does help in establishing the total tension on the piano however.  If
your new scale is somewhat low tension anyway it's probably not that
critical to have the original data.  But if you are moving in the direction
of higher tension I'd want to know where things started.  One does need to
be careful about increases made to the overall tension that might put too
much strain on the plate or overwhelm a weak soundboard assembly.



David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Dean May
Sent: Saturday, January 07, 2012 2:49 PM
To: joegarrett at earthlink.net; pianotech at ptg.org
Subject: Re: [pianotech] string scale

So what would be rescaling? Moving the bridges as well?

Dean

Dean W May (812) 235-5272 voice and text

PianoRebuilders.com (888) DEAN-MAY

Terre Haute IN 47802


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Joseph Garrett
Sent: Saturday, January 07, 2012 5:42 PM
To: pianotech
Subject: Re: [pianotech] string scale

Matthew asked: "Does anyone know where I can find (or happen to have)?a
string scale for an Ivers & Pond 1924 Grand, Scale 73?? It is not in the
"Guide to Stringing" by Travis.? Any help appreciated, thanks so much!"
 
Matthew, (with 2 t's<G>)
Sigh. This question just keeps coming back to the surface. It assumes that
what is in the book, etc. is correct! My experience says different.
The best way to do it, is to take all the measurements of the existing
speaking lengths and all the wire sizes. The most important part is to take
the BASS measurements. This is the main thing that is wrong with the travis
book. It only addresses the plain wire part of the scale! THEN, techs just
send the bass strings off to who knows and assume that the scale was the
best that it can be and the string maker is going to duplicate them
....exactly. Too many wrong assumptions to even think about in one
sentence! 
I strongly urge all to do the"math" or do all the measurements and send the
data to someone, like myself, that will analyze the existing scale and then
make the changes to give the optimum. If you are computer literate you can
do this. Ya really don't have to be some kind of math whiz kid!<G> The
formulae are available to all. Most techs make a spread sheet for this.
There are two ready made programs, out there, that will get you up and
running faster. They are from Mark Gallant, Assoc., Portland Chapter or
Tremaine Parsons, R.P.T., Sacramento Chapter. 
Yes, it takes a goodly amount of time to do all of this, but if you are
"re..whatevering", you need to have this skill!! Otherwise, leave the
"re..whatevering" to those that can/do.<G>
BTW, this is NOT RESCALING! (oooohhh the dreaded word!<G>) This is simply
taking given data, knowing the basic intent of the designer, eliminating
factory snafus and making it optimum for the given perameters available.
Once you've done this it's a must forever more.
Best Regards,
Joe


Joe Garrett, R.P.T.
Captain of the Tool Police
Squares R I