Finding the strike line another method

[Porritt, David]

I just moved 5 hammers in a killer section of a D.  It has improved (not
cured) that region some.  Do you think that this weak area of the board
benefits from some change in the strike ratio?  If the board in this
case were in good shape would it sound better as designed?  Here's an
area Dr. Stephen Birkett could study!  

dave

_______________________
David M. Porritt, RPT
dporritt at smu.edu

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On
Behalf Of Ron Nossaman
Sent: Friday, July 27, 2007 10:50 AM
To: Pianotech List
Subject: Re: Finding the strike line another method



>When you, or 
> Dale, have set up the piano with the curve in the line to get the best

> tonal result, do you find that the hammer is striking the string at 
> different proportions of the speaking length? 

This is a good question. We tend to presume that the piano was 
designed with a linear progression of strike ratio from the 
middle of the scale on up, and was built accordingly. But, 
even assuming that it was actually built to design specs, is a 
linear progression optimal? What are the determining factors? 
I haven't done any research along these lines, but I'd think 
that hammer hardness, weight, and resilience would be a factor 
in defining the ideal strike point, as would soundboard 
response, perhaps. The strike line deviations from a straight 
line happen in the low treble section - the killer octave. 
Why? Just hanging the hammers where they work best is good 
enough for getting the job done, but I'd like to know more of 
the why here. Another interesting thing to look into.

Ron N