stretching wire

[Dean May]

>>It's the best evidence I could find out there among real 
engineering sources.


Well here is one engineering source that is definitely not the final
authority, but I do have a mechanical engineering degree, BSME, and I am a
PE (Professional Engineer license). I am not aware of any steel wire that
has the kind of elasticity you are talking about (if I understood what you
have been saying). All of it will take some permanent set after being put
under tension and released, and all of it will creep when placed under
tension. Now it does reach a place where the amount of creep exponentially
approaches zero as the tension is maintained (i.e., the elastic deformation
(slack) is removed). Combine this with the soundboard becoming settled and
all the bend areas of the wire being set and you have tuning stability. 

>>But then I'd be at a loss as to why low panel compression rib 
>supported soundboards with laminated bridge caps stay in tune 
>so much better than traditionally built panel supported boards 
>with solid caps, using the same ever stretching wire. And no, 
>that's not my wild hair notion either, but is reported by 
>techs I've done belly work for.

No reason to be at a loss: the wire has reached a point where creep is
negligible, and your boards are more stable than others. End result is
better tuning stability. This does not prove by any stretch (no pun
intended) that the initial creep did not happen. 

Dean

Dean May             cell 812.239.3359 

PianoRebuilders.com   812.235.5272 

Terre Haute IN  47802

 


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Wednesday, April 09, 2008 4:44 PM
To: Pianotech List
Subject: Re: stretching wire


> The fact is you simply can't bear to have facts demonstrated to you that 
> aren't written ad nauseam in the Gospel according Ron Nossaman and that 
> any serious scientific data is beyond your powers of understanding.

Sorry John. This isn't some wild hair notion I cooked up on my 
own. It's the best evidence I could find out there among real 
engineering sources. This doesn't have my ego wrapped up in it 
anywhere. As I have said repeatedly, if you have an 
authoritative source that says modern music wire stretches in 
the long term under the conditions found in real pianos, I'd 
love to see it. It would make life so much easier to be able 
to blame the wire for everything.

But then I'd be at a loss as to why low panel compression rib 
supported soundboards with laminated bridge caps stay in tune 
so much better than traditionally built panel supported boards 
with solid caps, using the same ever stretching wire. And no, 
that's not my wild hair notion either, but is reported by 
techs I've done belly work for.


  > In the patent I suggested you look at, published in 1985, 
what sort of wire do you think they were dealing with, for 
heavens' sake?!  Of course you did not read it.

Apparently not, but then patents have been issued for 
perpetual motion machines, which might cast some doubt as to 
it's being a credible information source. I'll wait for the 
diversionary chaff to clear and see if a real echo appears on 
the screen.

Ron N