Cutting Frames

[Don]

Hi Ron,

I have posted about it before. Full perimeter plates and individually tied
strings are where I have noted less than usual pitch drops. One piano in
particular comes to mind, the Baldwin 6000. Plate flex at or near the hitch
pin may be less with one hitch pin per wire, even though the total tension
on the plate would be very similar. It would seem logical to assume the
hitch pin itself would bend less with only one string tugging on it.

Perhaps individually tied strings don't make of themselves a difference.
But for me they are a indicator that I need to reduce the amount of
overpull (or underpull) to have excellent results on a pitch correction. 

Interesting (and as usual informative) to see your run down on the causes
of pitch drop. 

At 10:32 PM 03/29/2001 -0600, you wrote:
>>If it is just the struts why is it not necessary to overpull as much on
>>pianos that have individually tied strings? (i.e. one hitch pin per wire)
>
>No, it's not "just the struts". Struts don't compress all that much, but
>they do bend. The span between the struts bends too, and that's what
>accounts for most of that pitch drop. Though this is the first time I've
>heard this one, individually tied strings don't have a thing to do with it.
>It's the plate thickness, depth of "beam" on the tension plane, and span
>between struts, and curvature of the hitch pin or aliquot line (and nose
>bolts) that will determine flex and vertical deflection.
>
> 
>Ron N
>
>

Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.

Tuner for the Saskatchewan Centre of the Arts

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