What matters most ?

[Richard Brekne]

A440A@aol.com wrote:

> Greetings,
>
> Richard asks:
> << Whats is more important to the <<heaviness>> of the action, the inertia
> of the hammer and top action, or that of the key. Or if there exists a
> kind of border condition where one becomes more important then the other
> and vice versa.... what is that condition ? >>
> >Or if there exists a
> >kind of border condition where one becomes more important then the other
> >and vice versa.... what is that condition ?
>
> Bill answers (in part):
> The only reason to adjust key
> inertia would be in meeting the requirements of top action inertia.
> So from a design standpoint, I'd say that top action inertia is the
> one to pay attention to. Key inertia is the tail on the dog which
> wags when its's happy with the weight of the rest of the dog.
>
>    Well, this isn't a simple subject for several reasons. The main one is
> that the final judgement is to be made by pianists, so a fluid and subjective
> slant is the foundation for all that follows.  The best we can hope for is
> generalities that apply to most. Softer hammers will be felt as "heavier" than hard
> ones, all other things being equal).

If we put aside from the voicing issues...and the roll friction plays... and reserve
them to be dealt with later... we still have much to be able to manipulate to influence
the sensation of "heaviness" or "lightness" no ? Generalities ... to some degree of
specificness seem obtainable... there are what... for basic ways of configuring an
action... heavy weights / low ratio, heavy weights / high ratio, low weights / low
ratio, and low weights / high ratio. Each of these present there own set of problems
and operating conditions.... and at some point inbetween all this we may find some
general tendancies that work well.

>    There are limits to how much FW can be used before the action becomes
> recalcitrant.  Excessive FW  presents inertial problems of its own, regardless of
> the BW or top action inertia.  Accelerating 50 grams of weight is a chore when
> attempting to play fast, so we can't just disregard key weight.
>    Leverage can really change the perception of heaviness, but not for both
> ppp and FFF playing.  A heavy FW might feel smooth and light when played
> slowly, but its inertial resistance goes up with the square of velocity,(I think),
> so that smooth,controllable action begins to fight back when you try to play it
> fast and loud.

I am not sure whether you are refering to counterbalancing or leverage in the above....
could you go more into how leverage itself (without regard to any particular mass
levels) influence the perception of heaviness ?

>
>   Soooo,  the more influential component in the action might depend on the
> dynamic level under consideration.  There is a golden mean in all of this, where
> the relative weights and leverages are in an optimum relationship.  I don't
> know exactly how to define it, but like porn, I know it when I see it.
> Regards,
> Ed Foote RPT
>
> (Ps,  Am I the only one that thinks the best feeling action has the
> capstan/heel contact point exactly on the centerline twixt whippen flange pin and
> balance rail pin when escapement begins???????  That is sort of a troll).

Dont really know... I havent really tried to correlate the above condition and the lack
of it with "the best feeling action". But I suppose I will get there soon enough...
grin.. I still got about 15 grands I can do with as I please.


--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html
http://www.hf.uib.no/grieg/personer/cv_RB.html