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Interesting thread on these action motion pictures. I've heard of such movie
made at Polytechnic school in Paris also. I am supposed to view them one of
those days (I can ask for more details).
I've heard of the bending of the shank/head at the joint, I believe that
over centering hammers is used as a process to avoid too much breaking of
the continuity hammer/shank at that place Kawai are slightly over centering
for what I've seen (???)
Thinning the shanks does not seem to give a thicker tone, but more
predominance of lower partials, known as 'whip effect' but the tone being
more immediate is also less evolving in time.
The action resistance, or what is perceived as weight by the pianist, is
IMHO mostly a result of action compression. I'd like to know when it begin
to occur, but from what I feel when regulating it seem to be at relatively
low speeds.
The other resistance due to the mass and weight of parts is IMHO again
mostly perceived only at the beginning of the stroke , during a very short
moment
For sure any weight added on the hammer will push the bending of the shank
in its limits.
I believe that we don't need too much weigh in the piano action, as when
properly regulated, the weight appears when necessary i.e. under faster or
heavier banging, just by the mean of action compression and changes in
synchronisms of the parts move/stops.
That is exactly what a fine regulation mean, using the touch /feel of the
action to allow the larger response from it under different form of touch.
All assist springs, counterbalancing weights, impede the speed and change
the mass properties in an unpredictable manner (at this moment)
I am more and more convinced that there is a certain range of configuration
adequate, ratio and action spread vs. heaviness of hammer, but the window is
less large that one believe I'd say.
What seem to miss is a way to ascertain at what moment the good heaviness or
BW is useful, and at what moment/under what configuration it's presence is
not adding something but a supplementary sensation that we don't know what
to do with it.
another thought is that it have been generally proved that a too large
evenness is not adequate for musical instruments, evenness of tone, evenness
of touch, etc...
For some reason that seem to lessen the pleasure of playing. I've seen kind
of instruments where this was perceptible.
May be because pleasure is related to surprize, a too predictable instrument
give less joy to master (up to some point) When a pianist use a new
instrument he made a mental map of it and his brain use these informations
when playing, may be a too liear feedback does not exite the little brain
celles (the one related to circles of sound) much !
A last but not least, is that many makers use a slightly different key ratio
on sharps whites. When seeing that thru the BW equation this looks like an
error, but up to some point the sharps can have this faster answer, because
the finger position on the white keys is more often on the middle of the key
than on the edge. The white keys are then more feeling as heavy than the
black ones. Nowadays that's un attempt to master that problem, and moving
the sharps capstan line, does not even the touch even under even BW
parameters, as the acceleration of the sharps is then of course different
from the whites.
The ratio diff white./sharps that shows up with the weight method may be
acceptable if it allows an even balance when measuring the weight at the
playing position on the whites , something around 2.5 cm from the edge of
the key, or a percentage of their head's length.
Sorry I am not that good for re-writing, just put one phrase after another.
Thanks as always for your insights.
Isaac OLEG
Pianomania
Isaac OLEG
accordeur - reparateur - concert 19 rue Jules Ferry
94400 VITRY sur SEINE
oleg-i@noos.fr tel:
fax:
mobile: 033 01 47 18 06 98
33 01 47 18 06 90
033 06 60 42 58 77
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-----Message d'origine-----
De : caut-bounces@ptg.org [mailto:caut-bounces@ptg.org]De la part de
Richard Brekne
Envoye : vendredi 14 novembre 2003 15:45
A : traylorg@equaltemperament.com; College and University Technicians
Objet : Re: Digital cameras (Piano Action)
"Garret E. Traylor" wrote:
This sounds like we could keep some graduate students very
busy....personally I don't know anything about physics or mathematics. But,
surely some time/motion study based from this improved filming technology
could reveal some very interesting data. "INERTIA relating to Piano Action
Geometry: The Qualitative and Quantitative analysis of Non-Rigid
components."Garret
Stephen Birkett is working out something along these lines. Myself I am
not so sure we need to get all that deep into the math/physics side of
this... We do need to be aware of the affects of various weight / ratio
configurations on any given degree of action compliance, and Del is right...
that is not being taken into consideration by many now.
When Stanwood puts a set of monster hammers on an action, and drops the
ratio down to 5.0 or lower.. (I think his personal record is a 4.8 BWRatio)
he doesnt worry about how much that actions felt compresses, how stiff the
keys are... how much flex there is in the shank... etc etc. Nor does he do
so for a 6.0 BWRatio with top medium hammers. He just balances things out
according to his predetermined specs dictated by the Balance Equation.
Yet it seems clear that the net compliance of any action is going to
change for various configurations, and that definatly affects how the action
feels, how it delivers its punch to the strings, and utlimatly how the voice
of the instrument sounds.
So... while Static Balance can provide us with exactly a static balanced
action.... it's less then << all we can easily do >> without some method of
putting this into a compliance perspective.
More or less the same kind of argumentation can be said about inertia.
Heck... seems to me that we dont really consider whats happening with the
employment of assist mechanisms conciously enough.
Cheers
RicB
Delwin D Fandrich wrote:
The bending spaghetti is the hammer shank with the hammer trying to
hold on. And then there is even more maccaroni if you start with the flexing
key. At the time between when the key is hit and the time the hammer finally
hits the string I have already eaten part of the salad.
Hans Sander
And yet we insist on discussing action geometry as if the various
components were all infinitely rigid and had zero inertia.
Del
Its a good baseline... but I agree... not much good in the end left to
itself.
RicB
--
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
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