Tripping, (was METHOD)

[Roger Jolly]

Hi Ed,Brian,Bill, Etal,
                                Excellent post on a tough subject, well
covered.
One oft omitted thing to look out for, refined after touch, and stable
hammer lines, are all but impossible to obtain if there is too much
friction in the balancier slot. Due to dried out grease or faulty spring
geometry. Gina and I have devoted a whole chapter in the Sept issue just on
springs. 
This thread has added some more food for thought, wish it had happened a
few weeks earlier. 
Get the preview in our Arlington class.  Shameless advertising. 
Roger
          


At 09:31 AM 02/07/00 -0400, you wrote:
>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 
> 
Roger Jolly
Saskatoon, Canada.
306-665-0213
Fax 652-0505