Pinning on new flanges

[gordon stelter]

O.K..  So where in the action do we want NO friction,
low friction, and/or moderate friction? And what are 

     Thump
 
--- Richard Brekne <Richard.Brekne@grieg.uib.no>
wrote:

> This is exactly the point I made to begin with when
> I brought up the 
> <<breaking function>> of friction.  This is why
> (half of why anyways) we 
> are looking at a trade-off (in the case of the
> hammer shank flange 
> center) between firmness and friction. The firmer
> the better with 
> regards to hammer contact, opposed to that is the
> need for a freely 
> playing action... but the needed degree of freeness
> is limited by the 
> need for some degree of resistance for the reasons
> you describe below.
> 
> And, as you point out, that exact degree will vary
> from pianist to 
> pianist dependant on just how much control they are
> able to exert on an 
> action, and with general styles of playing. 
> Further... it is no 
> difficult task to assert that the huge amount of
> data on the subject 
> shows clearly a preference for the kind of friction
> levels that have 
> become the industry standard.
> 
> Cheers
> RicB
> 
> 
> 
> V T wrote:
> 
> >Hello Friction Thread,
> >
> >Here is an additional view to get the conversation
> >heated up:
> >
> >The musician has roughly 10 mm of key travel to
> apply
> >the force to the key.  The choice exists of where
> on
> >the key to push, and how to time the force.  If we
> >plot a function of finger force vs. time, we will
> see
> >that the player controls his touch by modulating
> this
> >force during the travel of the key.  There is a
> >feedback loop at work and the player integrates the
> >force to get the proper momentum into the hammer
> head.
> > He may start with a higher force to get the static
> >friction out of the way, but then he might lessen
> the
> >force in order to create a soft blow.
> >
> >The following assumes that the balance weight is
> kept
> >the same when comparing the low friction to a
> normal
> >friction action.
> >
> >All mechanical systems have a "damping ratio". 
> This
> >is a ratio of stored to dissipated energy.  Control
> >basically amounts to being able to impart just the
> >right amount of momentum to the hammer.  A
> mechanism
> >with a low damping ratio (little friction) is
> harder
> >to control because a mass set into motion without
> >friction will continue to move freely.  The player
> has
> >no means to slow the mass down if he initially
> presses
> >too hard on the key.  His skills then consist of
> not
> >pressing too hard, or quickly backing off in case
> he
> >did press too hard.  This is exactly what a
> >"frictionless" action requires - the ability to
> change
> >finger force in an incredibly short period of time.
> 
> >Again, he has only 10mm of key travel during which
> he
> >can distribute the force.  For best expressiveness,
> >the musician would probably like to have as much of
> >those 10 mm available to modulate the pressure
> without
> >feeling that he is moving the key stick through
> >molasses.  If he doesn't have the physical ability
> to
> >reduce the force quickly, he will feel that the
> action
> >is "temperamental".
> >
> >The situation changes when very fast playing is
> >required.  The requirement for a precisely
> controlled
> >dynamic level may give way to the need for speed. 
> A
> >fast (low friction) action becomes advantageous.  I
> >think that pianists who like to play fast pieces
> and
> >have phenomenal control over their touch may prefer
> an
> >action with very low friction.  They have the
> ability
> >to put just the right amount of energy into the
> hammer
> >in the shortest amount of time, basically using the
> >initial stage of the key movement to send the
> hammer
> >on its way with the precise amount of momentum. 
> Since
> >they did all the work in the initial stage of the
> key
> >movement, they are free to quickly move on to the
> next
> >note.
> >
> >Vladan
> >
> >
> >		
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> >  
> >
> 
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