Re: Stéphane Collin

[A440A@aol.com]

 Stéphane Collin asks:
 
>> Am I right assuming that the more drop, the more and for
>  longer time friction between the jack and the knuckle ?  

    The jack is in contact with the knuckle from the bottom of the hammer 
blow to the point of let-off,(and even then, the distal side of the jack may 
lay against the proximal side of the knuckle, but that is not usually a 
factor in the feel).  
    After the drop button contacts the balancier, the jack has sole support 
of the knuckle.  On a hard blow, this is not felt, on the softest, you may 
find that the later the drop screw engages, the less friction there is upon 
let-off because the balancier is holding up part of the weight while the jack 
is pulled out from under the knuckle,  ( on many actions, you can actually 
play a note very softly with the jack removed, so the balancier CAN carry 
some of the weight all the way to escapement).  
   Having the drop set too low will create a larger zone before let-off where 
the pianist must play against repetition spring resistance. This will 
certainly interfere with pianissimo control, particularly when playing rapid, 
soft passages.  
 
> While we are on that subject, do you regulate let off by
> feel also, or with a gauge ?

  I regulate let-off by finding how close the hammer can be brought to the 
maximum excusion zone of the string without touching it.  That is why let-off 
is greater in the bass.  
 
>> Just another thaught : I sometimes feel that good touch
> feel is playing against good performance.  I.e. : I think I
> can achieve much better repetition when reducing aftertouch
> (but loosing the good feeling of the notch).  

  The speed of repetition is determined by how far the key must travel back 
upwards to allow the jack to reset, and how fast the key moves.  The distance 
the key must travel is determined primarily by the hammer-checking height.  
If one reduces the aftertouch by reducing keydip, the key has less distance 
to travel before the jack resets, but it is hard to change keydip too far 
away from 3/8".  You will also notice that, all other things being equal, as 
you reduce the keydip, you lower the checking height, so this is 
counterproductive to repetition speed.  
    The difference in key return speed between a very strong spring and one 
that slowly lifts the hammer from check is minimal, so excessive spring 
strength only creates extra resistance at let-off,(via the drop resistance 
and to a lesser extent, the jack's resistance).    
    A soft spring, jacks positioned as far proximal as possible without 
skipping, knuckle resting on both jack and balancier,  let-off and drop set 
to just clear the strings excursion zone, checking at maybe 1/2" to 3/8", and 
no more than .035" aftertouch will generally give you maximum ease of 
escapement with the fastest repetition that the action is capable of.  
   There are always qualifications.  Action ratios can affect rep speed, 
particularly when the capstans are brought closer to the balance rail.  This 
is due to the moment arm that the hammerweight has at its disposal to lift 
the keyweight.  While moving the capstans closer to the balance rail will 
often allow either heavier hammers or less lead in the key, there is a point 
of diminishing returns after which repetion speed will be poor, regardless of 
weights on either end of the equation.  
Regards, 
Ed Foote