<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <META content="MSHTML 5.00.2919.6307" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#d8d0c8> <DIV> </DIV> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A href="mailto:Richard.Brekne@grieg.uib.no" title=Richard.Brekne@grieg.uib.no>Richard Brekne</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = href="mailto:pianotech@ptg.org" title=pianotech@ptg.org>Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, April 29, 2003 = 12:07 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: hammer = velocity</DIV> <DIV><BR></DIV> <FONT color=#ffffff></FONT> <P>Hence the querrie I made about the "left over" force that could = possibly cause an accelleration of the hammer after the actual and direct force = of the key has been removed. <P>After several posts I think we all have gotten the point that there = has to be a force to accelerate/deaccelerate and object. Yet none of these = have really addressed the origional query satisfactorilly, tho a couple = have mentioned lightly the below. <P>What I'd be curious to know,  is if and when the flexing of = action parts can cause such an acceleration. </P></BLOCKQUOTE> <P><FONT size=2>At no point, except, possibly, very light pianissimo, = is the link between key and hammer as direct as we traditionally like to = assume. There is nearly always a certain amount of bending and twisting going on. = During this process it is possible that it could be contributing to some = acceleration somewhere at some specific time. But I wouldn't count on it. </FONT> <P><FONT size=2>The only quick answer I can think of to your question = goes back to the varying time lag between the start of key motion and the end of = hammer motion. This time lag exists because of the bending and compressing of = the various action components. If we were somehow able to use these bending = motions to accelerate the hammer to some faster velocity than would otherwise be = possible, it seems to me we should then be able to arrange for the = hammer to impact the string sooner than it otherwise would without this bending = and flexing. I.e., the bending motion would accelerate the hammer faster and = it would travel faster than would be the case with a perfectly rigid = action. Carrying this to its logical conclusion then, with a compliant action we = should be able to get the hammer to impact the strings somewhat before we = strike the key. Nice trick if only we could get it.</FONT> <P><FONT size=2>I think it is possible--probable--that the bending and = flexing motion of various action components--particularly that of the = hammershank--can and does cause the velocity and the motion of the hammer to vary. = Unfortunately, this is in no way controllable. And, I think, but have not proven, that = the velocity of a real-world hammer will always be somewhat less than it = would be with a perfectly rigid action.</FONT> <P><FONT size=2>Del</FONT> <BLOCKQUOTE style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: = 0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px"> <P> </P></BLOCKQUOTE></BODY></HTML>