[CAUT] pre-stretching new string?

[Richard Brekne]

David

I'n not being antagonistic at all. I am just trying to help you 
understand something you seem clearly confused about. The two unknown 
formula link you offered for example.... there is no way you can use 
that in the context you have suggested.  Its a completely different 
problem type.

The Tension formula is T = f^2*L^2*d^2* K  where K = the string density 
* PI / 981

You cant fit that into solving for an  aX+bY=c problem. 

There is no way around it. You can calculate the change in length and 
measure the pitch change to get tension... or you can calculate change 
in length and change in tension to get pitch.... but you have to get two 
of these in order to get the third.

As far as the diameter is concerned.  Use the spreadsheet I supplied 
with accompanying justifying formulas.  You can easily enough juggle the 
input tension for different wire diameters for same wire lengths to get 
the same starting frequencies. Then change the deflection input for both 
strings.  As long as they are the same length... any same deflection 
will cause the same frequency change.

Cheers
RicB


    See my other post but of course diameter plays a role.  It is a
    factor in
    determining break point percentage.  A thicker string will have a higher
    break point percentage and a thicker string will need to be at a higher
    tension to achieve a certain frequency at a given length than will a
    thinner
    string.  Simple stuff.  The claim about BPP as a factor in
    determining which
    string will go out of tune more goes way back.  You don't need to
    use BPP in
    the formula, you can simply calculate it for the two strings in
    question and
    observe the relationship-see my other (corrected post).  Please
    don't be so
    antagonistic.  I'm really trying to help you here.   

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