Spreadsheet info / Jason Kanter

[Jason Kanter]

Thanks all for the encouraging words. Ric is asking on my behalf, really,
for two things:
1. How you -- you with experience of the art of rescaling -- how much
variation you allow in tension, or what parameters you use in assigning
tension to a scale -- I understand that it is a balancing act between
tension, inharmonicity and Z - and am trying to implement ways to display
the variables and allow what-ifs.
2. Examples of actual numbers, especially where you have improved a scale.
This means string lengths, original gauges, and how you modified them,
perhaps with an explanation of why. Then I can try to get Excel to emulate
the expert thinking.

Getting Excel to interpolate string lengths etc. logarithmically etc is not
a problem, nor is looking up string diameters. Adding Visual Basic into the
mix adds significant power, so we may be able to have quite a tool sometime
soon. But, lacking the rescaling experience, I need expert examples and
guidelines.

Thanks again
Jason


On 12/17/06, RicB <ricb at pianostemmer.no> wrote:
>
> Hi Frank.
>
> I understand this to mean you figure your string lengths first, then
> figure string diameters to result in as even a tension (unisons or
> single string?) as you can reasonably get.  How much do you look at Z
> and inharmonicity... and basically how do you go about this.  Keep in
> mind we are looking for ways of providing some kind of automation for
> things usually done manually. A comment or two on how much leeway you
> give for each of these parameters would also be very helpfull.
>
> I get the feeling that excell may be too limited a tool for some of the
> automation we've been tossing around.  But thats what we are going to
> use so whatever is practical / doable will be attempted.
>
> Cheers
> RicB
>
>    .........
>    Starting with a blank piece of paper, designing a new piano, I prefer
> to
>    calculate the string lengths with a pure logarithmic progression,
>    and deal
>    with the dogleg of the bridge in other ways.  By making the distance
>    from
>    the front bridge pins to the back bridge pins longer on one side of the
>    break, and shorter on the other, the dogleg in the bridge can be
>    reduced.
>    The side bearing angle can be maintained, even thought the distance,
>    front
>    to back, is varied.  The bridge can be undercut, to further reduce the
>    dogleg of the bridge, at least with respect to the gluing surface
>    between
>    the bridge and the soundboard.
>
>    When it comes to restringing a piano, when the treble bridge is not
>    being
>    replaced, recapped, or repinned, I would not hesitate to reverse the
>    wire
>    gage progression across the break, when that would serve to smooth the
>    tension across the scale, in some cases, more than a half-size.
>
>    Frank Emerson
>
>


-- 
=cell 425 830 1561=
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