Soundboards/stress, questions

[Richard Moody]

I heard about 7 lbs per string caused by the bearing of the string
across the bridge.  That's why I would like to figure it out, only
that I lack the formula.  A string under tension when deflected
pushes back according to the angle and distance. (which are functions
of one another).  I bet the down pressure of string # 1  would
surprise us all.  This formula would also be useful for those of us
who manipulate strings under tensions such as for leveling,  using
the tool called  "false beat eliminator", and the other tool called
"string stretcher".

	At 7 lbs pressure, at 200 strings would be 1400 lbs.  a good size
cow, or I suppose a small elephant.  

Richard Moody  

----------
> From: JIMRPT@aol.com
> To: pianotech@ptg.org
> Subject: Re: Soundboards/stress, questions
> Date: Monday, June 16, 1997 7:44 AM
> 
> Richard;
> In a message dated 6/15/97 11:42:11 PM, you wrote:
> 
> <<The load or pressure on the sb from the strings, I was told
amounted
> to a small elephant standing on it.  Another source said 1,400 lbs.
> (either a small elephand or a large cow) Would like to find the
> formula to compute this.>>
> 
>  List, correct me if I'm wrong but isn't the typical pressure or
'down'
> bearing on
> the bridge from any individual string in the 1.5 to 3 lb range?  
>   So in a typical piano, such as a Baldwin Mod. 'A', which has 206
pins and
> therefore 206 times a string crosses the bridge, and using 2 lbs as
the 'down
> weight/pressure', the formula would be:
> 206 (2)= 412 lbs
> 
>   Of course Richard my initial premise could be wrong.  :-)
> Jim Bryant (FL)
> 
>