Ideal leading pattern: more questions

[David Love]

Bill/Roger/Newton:

Without even looking at the belly rail felt I can tell that everything is to 
far in.  The position of the hammer #88 is well over 5 1/8" and any attempt 
to reposition to action brackets and reset that capstan line would move the 
hammers way out on the shank in the upper end of the piano.  Which is worse? 
  And the key leverage is not great in the lower end of the piano either.  
The owners of the piano are not willing/able to go through a total redesign, 
and given the plate location, I'm not sure how I would go about solving the 
problem anyway.  At least not without remaking the entire action, keys and 
all.  The best solution short of that, to my thinking, is to go to a spring 
assisted whippen to at least allow me to remove as much lead as possible.  I 
haven't yet tested that idea.  Any comments?

David Love



>From: Bill Ballard <yardbird@vermontel.net>
>Reply-To: pianotech@ptg.org
>To: pianotech@ptg.org
>Subject: Re: Ideal leading pattern: more questions
>Date: Fri, 30 Mar 2001 20:03:31 -0500
>
>On Fri, 30 Mar 2001, "David Love" <davidlovepianos@hotmail.com> wrote
>
>>Admittedly, I don't make this measure of comparison very often but,
>>the capstan to balance rail distance varies by about 6 mm from end
>>to end, i.e., note #1, the distance is 106 mm, and note #88 is
>>112mm.  The capstan centers underneath the heel at both ends.  It is
>>counterintuitive if this is the design.  I operated under the
>>assumption that the balance rail, capstan line, front of key line
>>were all parallel.  If this is true (please correct me if it isn't)
>>it would seem that brackets were not squared up with the frame and
>>that the capstan line was then drawn at an angle.
>
>It's not true for NY Steinways. It has to do with their initial
>positioning of the keyframe and action under the strings. The
>keyframe gets a standard position in/out and they slide the top
>action in and out under notes #1 (a standard measurement) and #88 (by
>sound). When the positioning of the plate moves forward (away from
>the pianist), the action (especially at note #88) has to follow it.
>It your case, by 6mm. Check the thickness of the belly rail felt
>(between the back flange of the plate an the front stretcher). I'll
>bet it's thick, a sign that during the initial fitting of the plate
>to the block/rim, the fit was further forward than usual.  The bridge
>notching moves forward next, and following that, the top action on
>the the keyboard.
>
>>  Could this explain why I seem to need an excess of lead in the
>>upper end of the piano?  Interestingly enough, though the downweight
>>diminishes 50-47 from 1-88 (and the upweight follows inversely), the
>>action actually feels heavier in the upper end of the piano.  My
>>sense tells me that with the capstan line moving ever farther away
>>from the balance rail as you progress from bass to treble, that the
>>action becomes more poorly leveraged and therefore feels heavier in
>>spite of the fact that it is getting lighter.
>
>You got the leverage situation right. Immediately, the balance of the
>weight on either side of the key (dare I say Balance Weight) gets
>shifted to the backside of the key (the half carrying the action
>parts). So far only gravity is affected (ie., how much greater the
>force of gravity is on the back half than the front). Inertia will be
>affected when you add more weight to the front to counter that
>imbalance.
>
>That's shining my little flashlight on it.
>
>Bill Ballard RPT
>NH Chapter, P.T.G.
>
>"I go, two plus like, three is pretty much totally five. Whatever"
>     ...........The new math
>+++++++++++++++++++++
>

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