<HTML><HEAD> <META content="MSHTML 6.00.2900.2769" name=GENERATOR></HEAD> <BODY> <DIV>Wow! But you know what? It's almost a shame to learn the proper engineering, physics, and mathematics of these things as it spoils the mysticism; takes away the magic. It's kinda like finding out there's no Santa Claus (which I hope never happens). So I guess you are saying that swinging a dead cat in a cemetery at midnight, burning incense, and chanting mantras are no longer valid piano repair techniques, eh? What's next, man will someday fly??? A pox on thy birdhouse. Hope your 440 Hertz! So thanks for spoiling the fun—I suppose next you'll be telling us that the moon is not a vast potential source of freshly cultured butterfat!!! Fie, fie, ye foreign-based, scientifikle fiend! Were ya here, we'd try ye for a witch. </DIV> <DIV>Here in Salem, we don't coddle purveyors of unnecessarily alarmist futuristic wizardry, my friend, no siree ...</DIV> <DIV> May your pudding fall. Alan Barnard Advancing backwards in Salem, MO</DIV> <DIV> > [Original Message] > From: Ric Brekne <ricbrek@broadpark.no> > To: pianotech <pianotech@ptg.org> > Date: 11/05/2005 11:17:41 AM > Subject: Alans Puzzler > > Hi folks > > Spent about 40 minutes today with my handy dandly grand action model > looking at what happens when the jack top is too high relative to the > window.  I can say pretty conclusively a high jack top in itself is not > going to cause drop to dissapear.  Nor should it really.  If you take a > perfectly regulated action and then lower the repition lever so that the > jack top gets becomes high in the window you've done essentially two > things. One; you have caused the jack to have difficulty returning under > the knuckle,  and two; you've cause drop timing to be delayed a bit. > > This is where the symptom may seem to occur.  If you have a very tight > regulation with regard to letoff to begin with, AND dont do insure that > lett off and drop engage at the same time, AND have the jack just a tad > high, then when when the jack trips the rep lever stays in motion and > the hammer <<falls>> whatever little distance the jacktop is high in the > window.... until the rep lever gets engaged.  There is one spot where > this appears like no drop.. looks to be when the jack is about 0.5 mm > over the repetition arm window.  But its largely an illusion as drop is > just smoothed out and melded into what is normal aftertouch motion. > > If you have letoff set a bit more conservatively to begin with... or if > you insure that the letoff button and jack button engage at the same > time... then drop occurs as usual regardless of jack top / rep lever height. > > Cheers > RicB > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives </DIV></BODY></HTML>