[CAUT] Steinway repetition center pin height

[Richard Brekne]

AH !!

Yes... well this clears up things quite a bit.  One runs into a similiar 
situation often enough with the hammers just plain regulated too high 
often enough. Just recently ran into a case of this on one of Bergens 
more important instruments.  Oddly enough... the fellow who did the 
regulation was attempting to deal with repetition problems.... go 
figure.  Hammers were regulated in this case to 36 mm !!! from the strings.

I have not thought of this has being related to relative positions of 
the balancier and hammershank centers tho. And I am still a bit foggy on 
how these can contribute to this condition.  An explanation would be 
greatly appreciated.  On the surface of it... it would seem that as long 
as you regulate with in reasonable correspondence to specs... all should 
work reasonably well.

Cheers and thanks
RicB


    Greetings,

      I wrote:
     >>I think he is referring to capsizing the action, where the hammer
    shank is so far below its rest position that the jack cannot return
    under the knuckle. >>
     

        RicB writes:
        <<  I dont think I've ever run into this situation. And I am
        trying to picture how it could come about. Anyone care on
        expounding on this a bit more? <<


           Yes,  When the hammershank is too far above its rebound cushion,
    (often miscalled the "rest cushion"),  there exists the possiblitity
    that under
    fast repetition, the hammer will rebound all the way down to the
    cushion while
    the jack is escaped.  In this event, the key cannot return high
    enough to allow
    the jack to reset and the note will not play until the key has been
    struck
    several times and the balancier lifts the jack aaaallllll the way
    back up so that
    the key can reset.  The basic problem is that the knuckle can be so
    low in
    the coincidental arcs formed by the hammershank and whippen, (as
    measured at the
    knuckle/ repetition interface), that jack can't get underneath it
    from this
    low a position.    
          If there is a tremendous spring strength, this effect can be
    minimized,
    but then you have a very definite resistance to escapement, ruining the
    sensitivity of pianissimo playing.  
    Hope this helps,

     

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