[pianotech] PR follow up

[David Love]

Possibly, unless the bend was already there waiting to come home again.  

 

David Love

www.davidlovepianos.com

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Terry Farrell
Sent: Saturday, August 29, 2009 2:31 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] PR follow up

 

The stability after restringing has other issues including the straightening
of the wire at the terminations, the tightening of the coils, loops and
beckets, etc..  This is not really an issue on a piano that has already
achieved that type of stability.  

 

I agree with you generally, but in the case of a large pitch raise (or any
pitch raise - but certainly a large one), wouldn't some of the same be true?
I'm referring to the front scale segment of string mostly - if you turn the
tuning pin 1/16th of a turn, the string would move about 0.05 inches through
the aggraffe (or capo) - and so would the bend in the string that formed
while it was sitting in the aggraffe (or capo). Wouldn't that affect the
pitch stability of that note as that small kink in the string straightened
out over time?

 

FWIW, I know Ron N will be very unimpressed with me for not calculating the
change in length of the string as it goes from forming a small triangle to a
straight segment and the associated change in pitch. My only excuse at this
time is that it is 5:30 AM and I am working on my first cup of coffee.
That's my excuse......

 

Terry Farrell

 

On Aug 28, 2009, at 11:27 PM, David Love wrote:





What else do you think accounts?  Soundboard compression?  When a string
breaks and the entire section goes out of tune is it the loss of a few
pounds downward pressure on the bridge?  If so, then simply pressing down on
the bridge should put the piano noticeably out of tune.  But it doesn't.
Additionally, when you destring the bass on a piano where the bearing on the
bass bridge is pretty much zero, why does the tenor change so much in pitch?
On the other side, a single string breaking makes a change of over 300 lbs
of tension on the plate.  The removal of the bass strings results in a net
change of 7000 -8000 lbs.  I would assert that it is primarily (if not
exclusively) the change in the way the plate flexes that is responsible for
the change in pitch. 

 

The stability after restringing has other issues including the straightening
of the wire at the terminations, the tightening of the coils, loops and
beckets, etc..  This is not really an issue on a piano that has already
achieved that type of stability.  The net loss the comes about during a
pitch raise is due primarily to progressively added contractual tension to
the plate.  Other factors that affect stability are the ability for the
technician to stabilize the various string segments as Ron outlined in a
previous post, plus getting to a reasonable starting point from which to
start the fine tuning process. 

 

David Love

www.davidlovepianos.com

 

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