Tripping, (was METHOD)

[A440A@AOL.COM]

Ric writes:
<< I have always wondered if this period of time between when the elbow makes
contact with the let off button and the jack actually escapes the knuckle,
has a name. 

Greetings, 
    Gee Ric,  that sounds like you are describing a fistfight or a 
jailbreak!!  
For this interval, I submit "tripping".  That is what is happening to the 
jack, and it is what the pianist does when we get it exactly right.  


<<Beyond flat knuckles and the the jack position set screw, (if
any) are there any other considerations, if it seems too much or uneveness
is a problem. >>

    Everybody has their own way to regulate escapement, here is mine: it is 
suitable for high performance regulation.

   While not willing to give up full power, which requires the jack lie 
sufficently under the knuckle,  I want the piano to be as sensitive at 
ppppppp as possible.  So, that means minimizing the resistance that occurs at 
the moment the "trip" begins, (see how easily that word fits in here?).  
There are six adjustments that bear on tripping, (spring, key-dip,let-off, 
drop, balancier, and jack), beyond which we assume things like backcheck, 
pinning, knuckle and jack condition, etc. to be within limits.
    The jack has to be as far under the knuckle as required to produce full 
power, but no more. I test by stopping the hammer at various heights while 
thumping the key.
    The spring should lift the hammer as fast as possible without that lift 
being felt in the key. No more, no less.  If less, repetition becomes 
unreliable; if more, the trip becomes bumpy.
    The drop and the let-off are set to the same distance, (the least amount 
possible without the hammer reaching the string's excursion zone while 
touching either the jack or balancier).  The drop is dependant not only on 
the screw, but the key-dip, so the dip must be close before final drop is 
done. 
     Conventional wisdom lauds the mutual engagement of the tender and drop 
screw, and when it happens, it appears to be a display of elegant 
engineering.  However, if their engagement is staggered a slight amount, the 
perceived resistance to the trip is reduced.  A similar example is the 
staggering of the various registers of jacks in a harpsichord, if they all 
must pluck, (cluck?),  together, you have a very heavy, "poppy" keyboard.  By 
spreading the onset of the trip's resistance a little, some smoothness is 
gained. In pianos, this point is often moot, as various actions demand 
set-ups that put the contact points at various combinations. 
      The final decision in the trip is the setting of the balancier.  It has 
to be near its final position to get an even hammer line, which, along with 
let-off, has to be done before setting a keydip,etc..  but after everything 
is done,  the balancier can be raised so that only the barest contact between 
the jack and the knuckle can be felt.  I set this contact to be as light as 
possible and still let me know that they touch.  The effect is that the jack 
is in contact with the knuckle from the moment the key is touched, but on a 
very soft blow, the added support from the balancier is enough to reduce the 
pressure between the jack and the knuckle, reducing the effort that happens 
during the trip. 
      The combination of consistant aftertouch,( which I mentioned in the 
first post), soft spring, minimal stop distances, and propulsion help from 
balancier can make a very sensitive action. When everything is just right, 
the trip becomes almost transparent at pianissimo levels. It is also an 
action that can be very dependable, and speed is not compromised.   An action 
set up this way will play as fast as one with heavy springs and the increased 
drop they require, but will be far more enticing to play softly. 
Regards, 
Ed Foote RPT