more bridge design

[Farrell]

I think this particular comment about the 30 lbs. was regarding a bass bridge. If it is a bass bridge we are talking about, I would suppose the 30 lbs. is a fair number to use. Many rebuilders do not put any, or at most minimal (some just have the bass strings "kiss" the bridge top) downbearing on the bass bridge - so the bass bridge will have much less downbearing force per string.

Terry Farrell
  
----- Original Message ----- 
From: "Dave Nereson" <dnereson@dim.com>
To: "Pianotech" <pianotech@ptg.org>
Sent: Thursday, March 27, 2003 4:52 AM
Subject: Re: more bridge design


> 
> ----- Original Message ----- 
> From: "Don" <pianotuna@accesscomm.ca>
> To: "Pianotech" <pianotech@ptg.org>
> Sent: Wednesday, March 26, 2003 8:18 AM
> Subject: Re: more bridge design
> 
> 
> > Hi David,
> > 
> > I would not call 30 pounds of downbearing a humungeous burden. The "holes"
> > in a violin bridge are there to "filter" the sound. Downbearing on a fiddle
> > is almost as much as that on a piano.
> > 
> > 
> > At 02:42 AM 3/26/2003 -0700, you wrote:
> > >                 &          in it as possible.             
> > 
> > Regards,
> > Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
> > 
> > mailto:pianotuna@accesscomm.ca
> > http://us.geocities.com/drpt1948/
> > 
> > 3004 Grant Rd.
> > REGINA, SK
> > S4S 5G7
> > 306-352-3620 or 1-888-29t-uner
> > _______________________________________________
> > pianotech list info: https://www.moypiano.com/resources/#archives
> > 
> Really?  I read or heard somewhere that the total downward pressure of all the strings on the soundboard is about 1000, maybe 1500 lbs, divided by 200 some odd strings equals roughly 4 to maybe 7 lbs. per string.  
>     You mean if you were to put 30 lbs. distributed across both bridges of an unstrung piano, it would push the soundboard down to where it would be if strung and up to pitch?  I doubt it.  Or do you mean 30 pounds per string?  Then the total downward force on the board would be 3 tons!!!    I could see where the total downward force on the bridge of a violin or cello might be 30 pounds, maybe twice that, but probably less than a hundred.  
>     In any case, I just meant that if anything keeps the soundboard from being free to vibrate like a drum head, it's the downward pressure of all those strings, and not the mass of the bass bridge, holes or no holes.
>     --David Nereson, RPT
> 
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives