[pianotech] New string broke twice

[John Delacour]

At 00:13 -0400 14/07/2011, Noah Frere wrote:

>I read through the calculations page, did your calculation examples 
>therein to make sure I was using the calculator correctly, and 
>plugged in my values. However, my results differ significantly. I 
>assume I am doing something wrong. Here is what I got (in italics):
>
>T=(fld)sqrd/K
>
>Using .116" diameter:

Read it through again as carefully as I wrote it and you will get it 
right.  Note especially that there is no mention of inches and that 
'centimetres' is put in italics for emphasis.  I also included the 
exact keys to punch on the calculator:

       f x l x d x = ÷ k =

If you must use inches then you need to divide K by 41.62

       f x l x d x = ÷ k x 41.62 =


103.83 x 32 x 0.116    [382.336]
x =   [ 146181 ]
÷ 19400 =  [ 7.535 ]
x 41.62 = 314 (lbs.)

Otherwise forget about the 41.62 and simply use a value of K between 
493 (for the thickest double-covered strings) and 453 (for the 
thinnest single-covered).  If you use a fixed value of K of 480, you 
won't go far wrong.  This is something I do day in day out year after 
year checking odd strings that are sent me for replacement.

103.83 x 32 x 0.116    [382.336]
x =   [ 146181 ]
÷ 480 = 304 (lbs.)



JD