<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1170" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff><FONT face=Arial size=2> <DIV><BR>----- Original Message -----  </DIV> <DIV>From: Richard Brekne  To: Pianotech  </DIV> <DIV>Sent: Friday, April 25, 2003 11:59 PM </DIV> <DIV>Subject: Re: hammer velocity </DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> <DIV><BR>Richard Moody wrote: </DIV> <DIV> </DIV> <DIV>YES!  The hammer as it strikes the string is actually slowing = down in theory.    A major consideration of the design of the = piano action is that the hammer must leave the  impelling device, = <BR>(jack) and continue to travel for a tiny distance free and clear, strike the = string, rebound, and then come back in contact with the action mechanism which = must now "catch" the hammer. </DIV> <DIV> </DIV> <DIV>I believe there is a letoff position (just under 1mm) that is so = close that the hammer does not have a chance to start de-acceleration. I havent = gotten into all this side of things very much yet, so I am not sure of myself here, = but isnt there some sort of "left over" force that keeps an object in = acceleration for some small period of time even tho the origional applied force is = removed ?  Like a bullet coming out of a rifle ?? Doesnt that meet its = maximum acceleration some few milliseconds after the explosion of the shell ? = </DIV> <DIV> </DIV> <DIV>RicB </DIV> <DIV> </DIV> <DIV>    No, Richard, no "left over" force is there to = continue accelerating an object after it's direct influence is removed. If you = really want to know what happens inside a rifle, feel free to write me privately. No, the bullet doesn't continue accelerating after = leaving the barrel.  The only thing that I think could possibly continue = accelerating a hammer after the jack has tripped would perhaps be the flex of the shank = becoming straight again, but at 1 mm, I'm not sure that it could be = measured without high-speed cameras to capture the action. </DIV> <DIV>    In reality, the pianist has the skill to adapt = to the instrument, and still make music.  All we can do is to provide them = with the best regulated and voiced instrument we can, and they can take = it from there, if they are truely "musicians".</DIV> <DIV>Kevin.</DIV> <DIV> </DIV> <DIV> </DIV> <DIV> </DIV> <DIV><A href="http://www.papercut.biz/emailStripper.htm"></A></FONT> </DIV= ></BODY></HTML>