[pianotech] Steinway A Bass String Rescaling

[William Truitt]

Thanks for your further input, Ron.  I'm looking forward to playing with
this scale in PScale.

Will

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Friday, May 22, 2009 8:07 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Steinway A Bass String Rescaling

William Truitt wrote:
> Hi Ron:
> 
> Is there a target breaking percentage you try to aim for when doing this
> sort of rescaling?  

Not really. I try to get A-0 into the high 30s, low 40s.


>How far up from the bottom are you decreasing the core
> sizes and increasing the wrap?  

Not necessarily increasing the wrap. I'm watching tension, Z, 
break%, and how the transitions blend. It's not a standard 
deviation from the original, because the original could be 
literally anything.


>Is there a core size to wrap size ratio that
> you do not want to exceed?  

Not as such (I don't have a number "rule"), but  there are 
considerations. In a large piano, I'll likely do a 0.051" core 
at A-0 if I can make it fit. In a smaller piano that has a 
heavy wrap because of the string length, I'll go with 0.053" 
core. While the smaller piano could benefit from a more 
flexible bass string, it's harder for the string maker to wrap 
on the smaller core. The whole thing is a series of balanced 
compromises.


>Finally, since the tensions increase as well,
> what limits do you want to respect?
> 
> Will

Bass tensions in my scales, overall, tend to decrease 
slightly. When they do increase, I try to keep it within a 
couple of hundred pounds total. I try to limit break% in 
wrapped strings to 55% with Sanderson's formula. I go over 
sometimes, but not by much.
Ron N