[pianotech] Regulating drop and controlling semantic drift

[Richard Brekne]

Hi Israel. Sorry to have been off this for a few days... busy busy 
busy.  I have to take exception to your assessment below. First off I 
was not talking about the drop screws function... I went as directly to 
the basic function of drop as I think one can.  It is kind of hard to 
leave out mentioning the drop screw along the way... but I hardly made 
much more a point out of that then to mention its affect on touch. The 
jist of the post was contained in

    "The whippen has to hold the hammer firmly up... enough to avoid
    checking on a soft blow, enough to lift the hammer firmly upon
    release of the key.. or if you like push the hammer and the key in
    opposite directions in strong enough fashion to facilitate
    repetition. So it has to have a stop mechanism to avoid pushing the
    hammers into the strings after let-off. The drop screw does this but
    creates a touch component of its own in the doing. "

and to point out that adjustment of this component does indeed affect 
other things.  Steven quite nicely picked up on the point and discerned 
that his (via Baldassin) points out is that the adjustment of the screw  
"will not change any other regulation setting".... quite clearly 
dividing the two territories of the drop screw itself and the general 
function of drop. No dust up here, just a bit of understanding each other.

I cant on the other hand see that saying the purpose of drop (in the 
general sense) is to make "the exact point of letoff is visible"  Drop 
has a clear function... and the drop screw regulates that function.  It 
is to provide a stop mechanism for the rise of the hammer after letoff 
through the full motion of the key. This need is caused by the 
employment of a repetition lever and spring which while providing for 
faster repetition would, without the stop mechanism provided by drop 
cause the hammer to re-engage the string.

I'd also add that with even close to in tolerance hammer center 
pinning... close drop and lettoff regulation will not allow for the 
hammer to rehit the string even with quite strong spring regulation. It 
doesn't happen. The hammer can simply not gain enough momentum to carry 
it through. The spring would have to be regulated absurdly strong, big 
whopping kick back felt in the key, and you'd have to have far too loose 
a pinning for this to get into the picture.

The validity of Susans quote has to do with let off itself.  If THATS 
very close... then blocking can intermittently occur.

Cheers
RicB

    Israel writes:

        "Most of the very eloquent, expert and detailed answers posted
        answer a very different question, that is "what is the function
        of the drop screw".

    and

        "So the entire dustup between Steven Hopp (quoting Baldassin)
        and Ric Brekne appears to be apples and oranges - Hopp/Baldassin
        are talking about the amount of visible drop, and Brekne is
        talking about the function of the drop screw and why rep lever
        escapement should occur before letoff escapement. This is why
        semantics are important..."