Spring fever (or feverish springs)and not chomping

[Richard Moody]

ONE test for repetition spring tension correctness, is to find "chomping".
 To do this, play one key quicky with two fingers ( from each hand) in
rapid succession.  If the hammer "bogs" or "chomps" into the back check,
one of a few things MAY be wrong.  The first two considerations are weak
balance lever springs, or incorect back check position.  Tail
configuration could also affect this.  This should be used judicially, as
most all pianos can have at least four  keys that does this. You don't
want many more keys with this problem . The only thing you can do with
balance lever springs is NOT to have the hammers thrown to the string, or
NOT to have the weight of the hammers sink the balance lever so that the
tails check. Anything in between is what the two Eds describe below.
Richard Afterhavingfilledthehammers Moody 

ps  Woe is me. The players lurking on this list are gonna  check this out.
 Oh well you gotta earn your $30 per hour.      

----------
> From: A440A <A440A@aol.com>
> To: pianotech@ptg.org
> Subject: Spring fever (or feverish springs)
> Date: Wednesday, March 25, 1998 1:06 PM
> 
> Ed T writes:
> << You can weaken the rep
> springs to where at a soft blow as you described it would feel better to
you
> but the trade off is in fast repetition.  This is the side I want to
fudge to.
> I believe, as Yamaha, to set those reps with a fast rise..>>
> 
>       Hmmm,   has anyone found that rep springs give faster repetition
when
> they jump hard enough to be felt in the key, as opposed to those springs
that
> are set only as fast as possible to not be felt? 
>      I ask this because repetition speed has not, in my experience, been
> compromised by the softer setting.  It helps to remember that the spring
does
> not lift the hammer during fast repetition.  It lifts the KEY!!  
>       You may demonstrate this by striking a note, and with the hammer
held in
> check,slide you finger off the front of the key, allowing the fastest
possible
> resetting of the jack.  You will see that the hammer does not rise one
bit,
> but rather, stays in place until the key has risen enough to allow the
whippen
> to drop, which the shank then follows.  If you have doubts, go to your
action
> model and place a finger directly over the hammer and check, then let go
of
> the key.  The hammer will not rise before it drops.  We set the springs
by
> observing their rise rate, but in fast repetition, the hammer begins
each
> repeated note from its checking distance. 
>     The spring speeds repetition by more quickly overcoming the inertia
of the
> key;  it does this by pushing off against the leveraged weight of the
hammer.
> The difference in key return speed between a spring that "kicks" and one
that
> isn't felt is minimal.  
>    Of far greater importance to repetition speed is the height of the
> checking.  It determines how far the key must rise before the jack is
reset.
> It is also important to know that the softer the spring, the more
consistant
> everything in the action must be to perform, i.e.  erratic pinning will
> require the springs to be set stronger, just for a margin of safety.  
>    When Alicia de la Roccha played here, she stood up from the Steinway
D, (
> with my "soft" springs in it, and said " This is the first piano I have
ever
> played that I don't need to have the technician speed up,  just tune it,
but
> don't touch that action!".  
>     Also,  with the softer settings, the drop can be set at let-off
distance,
> further increasing the sensitivity of the action at pianissimo levels of
play.
> This is important when you have the let-off set to just barely miss the
> excursion limits of the string.  
>    Perhaps for the average-use instrument, strong springs allow fewer
service
> calls , but for ultimate performance, they get in the way.  
> 
> (Hot Damn!!  Flame suit fresh from the oven, pulled on and zipped up
> tight!!!!!!)
> 
> Regards to all, 
> Ed Foote
>