In a message dated 11/26/2009 1:07:23 P.M. Central Standard Time, wimblees at aol.com writes: The term "drop" is a misnomer. I agree. Just as "dip" is, and should be likely be called "key travel" or "front key travel". We regulate the "drop" screw so that it touches the top of the balancier to coincides with the tail of the jack hitting the let off button. We might. At that point, the jack starts it's escape from the knuckle, and the balancier is getting out of the way of the knuckle, to allow the hammer to travel freely towards the string. This is actually a misleading characterization of the events. If the jack tender contact on the let-off button and rep lever contact with the drop screw are simultaneous (which might likely be ideal), then the two (con)sequential events are the process of jack escapement leading to let-off, and the process of rep lever rotation leading to a highest possible position of the rep lever after let-off. The rep lever also continues to rise after contact with the drop screw but at the fulcrum (rep lever center) since the whippen is still rising, and does not lose contact with the knuckle. At the point of jack escapement, the knuckle loses contact with the jack top and rep lever both, thrown to the string on its own momentum. It is important to hold in mind the "simultaneous" nature of the escapements, and the sequential nature of the results of the escapements--let-off, then drop. The other so far unaddressed result is that the hammer on a medium or hard blow into check, then released, will rise to the position of the drop dimension from the string being raised by the "properly" sprung rep lever which is regulated to the drop dimension. Obviously all sorts of the things can go wrong with such close tolerances--spring regulation, check regulation, etc. We measure this by seeing how much the hammer "drops" after letoff. The closer we can get that relationship, the better it feels for the pianist. The more accurate name of the drop screw should be. "The button that gets the balancier out of way". Again, mischaracterized, and better (and not my language) "the repetition lever upstop screw". The so-called drop screw does not get the lever out of the way, but more aptly positions it in the proper way for the knuckle to return and for efficient repetition. P Willem (Wim) Blees, RPT Piano Tuner/Technician 94-505 Kealakaa Str. Mililani, Oahu, HI 96789 808-349-2943 _www.Bleespiano.com_ (http://www.bleespiano.com/) Author of: The Business of Piano Tuning available from Potter Press www.pianotuning.com -----Original Message----- From: Chuck Raynor <diggeray at comcast.net> To: pianotech at ptg.org Sent: Wed, Nov 25, 2009 6:49 am Subject: [pianotech] Regulating drop Hi list, I've been reviewing my notes from "Are You Regulationally Challenged?" which was presented at Grand Rapids this summer (great!!) and remembering a few other comments I heard, and have a few questions. In that class we were taught to set the drop screw to attain "simultaneous escapement"--essentially that the jack toe would hit the button at the same time the rep lever hit the drop screw, which results in a very small drop. On several grands I've tuned recently, I noticed that there was WAY more drop than that (and way more than the maximum 1/8" than I would normally expect). I guess my question is "what's the purpose of drop?" Israel Stein says "so you know you have letoff". Will too large a drop effect repetition? Will it also effect the touch of the piano? That's my thinking, but I'd love the input of the experts so I have it firmly (and correctly) in my mind. Thanks, Chuck Raynor Raynor Piano Service St. Helena Island, SC= -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20091126/218a8fe4/attachment.htm>
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