[pianotech] justify pitch raise

[David Love]

I agree, 8 cents is too much to expect that the piano won't have some
wobblies somewhere.  Three to four cents is my general limit and even then
that's pushing it (although I have been known to push it on
occasion...shhh).  Plate flexing makes the most sense otherwise on a board
where you've pushed the crown through to negative wouldn't letting off the
tension raise the pitch :-)?  Kidding of course (before anyone takes me
seriously).

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Friday, April 03, 2009 9:25 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] justify pitch raise

Norm Barrett wrote:
> I asked Dr Sanderson how far off a piano needed to be to need a pitch 
> raise and he said 8 cents. Also when new I was taught that this was 
> caused by the strings pressing down on the soundboard. 

We all were, but it doesn't realistically compute.


>This theory does 
> not make sense for the pianos that have no downbearing. I believe that 
> the plate flexing is the largest factor and the combination of these 2 
> factors means that each piano is a little different and some are easier 
> that others.
> Norm Barrett

Plate flexing makes far more sense to me, but the 8 cents, 
while technically realistic, is functionally impractical in 
real world situations.

Ron N