[pianotech] Breaking bass string

[Delwin D Fandrich]

Over the past 5 to 7 decades there have been quite a few pianos built with
speaking lengths at C-88 between 52 and 54 mm. Quite a few of the Japanese
pianos have come with C-88 speaking lengths of 55 and 56 mm. Aside from
those pianos using excessively dense and massive hammers there hasn't been a
lot of string breakage.

ddf

Delwin D Fandrich
Piano Design & Fabrication
6939 Foothill Court SW, Olympia, Washington 98512 USA
Phone  360.515.0119 — Cell  360.388.6525
del at fandrichpiano.com — ddfandrich at gmail.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Sunday, April 10, 2011 12:45 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Breaking bass string

>...it would appear by your standards that the maximum speaking length 
>at #88 would be something like 46 or 47 mm for #13 gauge and I see this 
>exceeded all the time both by accident and design without adverse 
>consequences...

I repeat, once again, that the 70% is the limit for *bass strings* which
very rarely have a #13 core.  I see 50mm as a good compromise for note 88.
The old wire (especially Poehlmann over here) was phenomenally strong and
some makers pushed their tensions to the limit relying on its strength.  The
reason I became a stringmaker was that I couldn't get anyone to make me a
set of strings for a Schiedmayer grand that would not break.  The top 5
singles had been replaced so many times that the frame was all chewed up and
the 7.75mm pins were still not holding the pitch.  Stringmakers just copied
the old strings using the weaker modern wire and they broke before they came
to pitch.  There are several famous makers who were almost as bad....

JD