laminated ribs

[Ric Brekne]

Thanks guys... dont know why on earth I got the idea that I had to split 
the 160 pounds in half... grin.. tension remains the same regardless.  
Then on top that thinking I had to only take one side of the 
<<triangle>>... sheesh. Anyways, thanks for straighting that out for me.

A question came to mind however in reading Rons post when he mentioned 
the following.

    "When looking at a given piano, I suggest that you set up a
    spreadsheet to calculate the downbearing force you are planning to
    set up per rib."

Right under a rib I suppose the support is strongest... and gets a bit 
weaker as you move away from the rib. How do you figure the distance 
needed between two ribs then ?

Thanks
RicB



Steve Fujan wrote:

String Tension  x  Sin(downbearing angle) =3D Downbearing Force
i.e.   160 x Sin(2 degrees) =3D 5.58 pounds  (3.49% of string tension)

Ron Overs wrote:

The downbearing (vector) force on the sound board
is equal to the SIN of the angle of deflection
times the string tension.