Shigeru Kawai regulation

[A440A@AOL.COM]

Dan writes; 
<<On the other hand, I do not concure with the idea that the rep lever
can be thought of as contributing to control in ppp playing. << 

   Ok,  but I just took the jack out of a whippen and I can still play the 
notes, some surprisingly louder than I thought.  And this is not with an 
overly strong spring!  My main point was that properly set, the balancier(rep 
lever) can create virtually a frictionless escapement under ppp playing. 

     
 >>When drop screw and let-off button are touched at the same time, I beleive
the following are true, and support the contention that the pianist is not
'playing off of the rep lever'.
 
1- The hammer is 3/8 ths plus 1/16 th. from the wire( depending on the
condition of the knuckle)
2- The rep lever is spring loaded, a poor canidate for lifting the hammer
3- The direction of movement of the rep lever after touching the drop button
is horizontal, not vertical.>>

    Inre #3.  The balancier's direction of movement doesn't become 
horizontal, but is still upward. What changes is the point of rotation.  
Before contact with the drop screw, the balancier's contact point with the 
knuckle is rotating on a radius from the whippen centerpin.  Upon contact, 
its center of rotation shifts to the dropbutton contact point, at which time 
the radius begins to be described by the balancier's centerpin, still being 
lifted by the key.  This represents a major change in moment arm, but not a 
change in direction from vertical to horizontal,( at least, that's the way it 
looks to me.  
    To use your figures of 3/8" engagement and 1/16" escapement, that means 
that for the 5/16" prior to let-off, the balancier is still in contact with 
the knuckle.  It is during this period that the balancier can reduce the 
friction between the knuckle and the jack for ppp play.  The distance over 
which the friction can be lessened is also dependant on where the jack sits 
under the knuckle.  
    I still champion  minimizing the amount of jack travel (by bringing it as 
far proximal as performance allows), setting the spring to its least positive 
strength, and setting let-off and drop at the same distance.  I think this 
allows the least resistance to the softest play.  Once done like this, you 
can take the jack out and the note will still play the same at ppp.  
     This is ONE reason, I keep my balancier as high as I can. The other is 
simply to reduce the total amount of work that the pianist's fingers must do 
in the course of a lot of play. When you consider that some of the serious 
classical people spend four hours a day playing, the grams add up.  
Regards, 
Ed Foote RPT