String breakage (was Re: I Raise the pitch...)

KUANG v137z2ng@ubvms.cc.buffalo.edu
Thu, 10 Apr 1997 00:35:43 -0400 (EDT)



On Wed, 9 Apr 1997 MHoffman11@aol.com wrote:

> In a message dated 97-04-08 19:31:16 EDT, you write:
>
> <<
>  I have heard this method mentioned many times in my years of tuning pianos,
>  tuning the pin flat before going up in pitch as a means of reducing string
>  breakage.  I was wondering if any others also have personal experience or

without doing this procedure (tuning flat), the string will only break if
there's alot (e.g. lots of rust) of friction at V bar.  I think it's very
unlikely though.  A very experienced tuner can probably answer this
question.

>  knowledge concerning this procedure as really being beneficial, or is this
>  possibly one of those proverbial "wives' tales" handed down through the
>  ages.  Don't have a clue myself.
>   Sincerely,
>  Keith A. McGavern >>>>>>>>>>>>>>>>>
> >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Hi Keith and everyone else:
	Here's a little story I'd like to share:  Last year Deputete
(forgive me, I really forgot how to spell his name, he's a famouse french
pianist living in New York)  gave a solo recital at my university.
Everything went very well except a string broke during the first half of
the concert.  Someone told me that he's not coming back because of that.

	I can conform that tuning pin flat before going up in pitch means
alot of string breakage.  But on the other hand, it is less likely that
any string would break when someone is playing the piano.  Of course it's
not the tuners fault if a string breaks.  But maybe it's a good idea if
we (as tuners) break the strings before anyone else do!  As a pianist
myself, nothing is more annoying than playing on a piano with broken
string.  however, if you wish to make more money (here's another 10
grands a week ad on internet ;p ), make sure all the strings are ready to
break after you leave your customer's house so you can charge more next
time you come back.
	Besides this, I think there's another good reason why this
procedure is important.  Stability.  Imagine a string in 3 sections (a V
bar between section 1 & 2, and a bridge between section 2 & 3, of course
there are bridge pins and more but let's forget about those for a
moment.).  Initially the string is flat because the piano hasn't been
tuned for a year and all 3 section have the same tension.  Now if someone
raise the pitch without tuning flat initially, it is very likely that
section 3 would have the same low tension before the pitch raise because
of (static) friction at the bridge.  The click you hear is the sound the
string makes when the torque of your tuning lever overcomes static
friction at V bar.  This is a very brief explaination (there's alot of
mechanical physics in this).  At this opportunity, I'd like to point out
something.  Based on theory, this effect is very minimum if section 3 is
very short _relative_ to section 2 (unless the string is not flexible).
So if section 3 is longer then section 2, then this effect should never be
ignored (now, only if someone who has all the time in the world would do
an experiment and prove my prediction...).  In summary, if you ignore the
procedure and section 3 happens to stay at low tension, then at some point
(let's say a kid like me bang on the piano) when all three section achieve
mechanical equilibrium, the note is gonna be flat (wait, isn't that what
they call a "settling period" after a pitch raise? :p ).
	There's a reason why strings are more likely to break if it's
tuned flat before going up in pitch but I guess I shouldn't waste more
bandwidth on that subject (I'm sure some of you already know the reason).
After all, experience is what counts because nothing is absolute.
regards
Kuang

>
> Hello Keith & Listees:
>
..
[skipped]
..
..
>
>
> Stay Tuned!

Let's hope so.

>
> Mike Hoffman, RPT
> Marquette, MI
>




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