Action Geometry, my thoughts

[Jon Page]

>~~~
>Jon,
>It's been a long day and my brain is having a hard time with this
>statement. Can you help me understand what you are saying here? The way
>I see it, yes, the damper COULD lift as high if you made other
>adjustments as well, i.e.,increase key dip. If you just left the
>relationships as is I do believe you would run out of keystroke before
>you could accomplish the same work as before, which is to lift the
>dampers to the same height. Can't be done as I see it. Am I missing
>something here?
>
>Joseph Alkana

The damper analogy was in regards to the range of motion issue with the 
jack lifting later
because the knuckle was placed further out on the shank.

However, given a set key dip, the damper will lift to the same height 
irregardless
of its lift time during the key stroke because it is the range of motion of 
the key
itself which determines the arc period. I am speaking of grands, uprights are
a different kettle if fish.

If you change the time the grand damper lifts without changing key dip, the 
key end lifter
felt height ends up at the same height, so the damper is lifted to the same 
height.

So by delaying the jack to letoff button contact time, the jack will still 
end up in the
same juxtaposition to the knuckle because the wippen is still being moved 
through
the same distance.

So with fixed components within the key stroke (L/O, hammer length & blow, 
key height & dip)
the variable for optimum regulation is capstan placement. Change any one of 
those components
and the equation for optimum jack location changes as well.

I'm not saying that there is only one location for the capstan, there is a 
narrow range to adhere to
for producing adequate leverage with resultant after touch.

It's a little confusing to me too.

Regards,
Jon Page

At 09:08 PM 06/08/2000 -0700, you wrote:


>Jon Page wrote:
> >
> > Diane,
> > One way I look at capstan placement is to position it to move the wippen
> > through the optimal distance.
> >
>
> >
> >
> >(having a damper lift later does not mean it does
> > not lift as high)
>
>
> > Jon Page
> >
>
> > >Diane Hofstetter
> > >Jeff Williams
> > >________________________________________________________________________

Jon Page,   piano technician
Harwich Port, Cape Cod, Mass.
mailto:jonpage@mediaone.net
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