stretching wire

Richard Brekne ricb at pianostemmer.no
Thu Apr 10 16:53:34 MDT 2008


Hi Dean..

One question I have right off...

Given that a pianostring would <<elongate>> the 0.127 mm mentioned below 
(.005 inch), what practical difference would this make to the pitch of 
the string ? Its not like the distance between the terminations is 
changing. The diameter would decrease ever so slightly... have a hard 
time imagining that that would even figure into the picture but perhaps 
I am wrong... which leaves only a reduction in tension due to this 
elongation accounting for any pitch change.... which would always go 
downwards unless there is some kind of reverse elongation that can 
happen when you lower tension as we often do after a summer...  And if 
its a change in tension due to an elongation process.... well that kinda 
sounds in layman speech like stretching to me.

Got some encouraging words for a itch on my left temple ?

Cheers
RicB



    I don't think this degree of plastic deformation stands in the way
    of the
    "strings don't stretch over the long term" idea.  First, keep in
    mind the
    amount of stretch cited here.  Even at the 300 pound tension, the
    plastic
    deformation was given as about 5 thousandths of an inch.  Maybe
    significant
    in some way, but it sure wouldn't account for any "winding up of
    wire on the
    tuning pin."  

    Agreed. The sample wire size was 6" long so for a 30" wire your
    .005" would
    end up as .025". But we are talking pretty small movements of the tuning
    pin.

     

    Dean




More information about the Pianotech mailing list

This PTG archive page provided courtesy of Moy Piano Service, LLC