Ed Foote wrote: > This confuses me. Is this position describing the jack being moved > distally so that it is farther under the knuckle? If so, ( all other things > being equal), it will move farther when placed in this position, since the > tender is brought closer to the let-off button and will contact the let-off > button earlier. And how does the rest position, which is governed by the > jack adj.screw, have any effect on the position of the jack when the hammer > is held in check? > Jon Page wrote: > I don't see how moving the jack back will bring it closer to the > knuckle when tripped, it will just drag it thru more distance; and > places it in contact with the letoff button sooner. Both Ed and Jon immediately thought this through and came to the same conclusion at the same time. See how genius can occur simultaneously in different locations? Both are correct that the jack tail hits the let off button slightly earlier and the jack starts it movement slightly sooner. In anticipation of everyone running out to the garage to delve into the mysteries of jack movement, I got out an action model. I regulated the jack as normal, pressed the key and put a light pencil mark on the side of the repetition lever where the jack ended its travel. Then I adjusted the jack _substantially_ back, away from the player. Pressed the key and, as Ed and Jon theorized, the jack wound up at the same place, not as I thought, closer to the knuckle. But I still think this works, only now I have to figure out why. My thinking is that this gives the artist the feeling that there is more room at the "bottom" area of the key travel in which to work his/her repetition magic. If you duplicate my experiment, do you think that a little more movement of the jack causes just a little more spring pressure on the jack down where that type of spring enters the jack, which may quicken the jack's return? Horace Greely also points out a very relevant side point: > The consistency is sometimes a problem on a piano with front rail > punchings that are too soft. After a good deal of playing with different > things, I have wound up using the Renner-supplied Bosendorfer punchings. > What makes them superior is that they will maintain a consistent keydip > with a variety of "touch" (read "hardness of blow") - the result is that > you have a sound (sorry) foundation on which to build the rest of the > regulation. > It's very advantageous to have a solid, secure end to key travel. Thanks to all who have joined in this discussion. It makes us think and that can't be all bad! ----Joel
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