<!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 6.00.2800.1106" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Dave,</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Yes, but I think it would be such a = small effect we can ignore it.  The mass of the hammer is so much greater than the = mass of the shank, that as the shank springs back to it's original form it would = be the shank which is accelerated by the hammer, not the other way = around.  </FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Mike</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Piannaman@aol.com href="mailto:Piannaman@aol.com">Piannaman@aol.com</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, April 28, 2003 = 12:32 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: hammer = velocity</DIV> <DIV><BR></DIV><FONT face=arial,helvetica><FONT size=2>In a = message dated 4/27/03 7:12:21 AM Pacific Daylight Time, <A href="mailto:mjbkspal@execpc.com">mjbkspal@execpc.com</A> writes: = <BR><BR><BR> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">Between let-off and impact, the jack, rep lever, and = string are not in contact with the knuckle.  The list of forces acting on = the hammer/shank assembly consists of gravity and center pin. =  period.  Both are acting to decelerate the hammer.</FONT><FONT lang=0 = face=Arial color=#000000 size=3 FAMILY="SANSSERIF"></BLOCKQUOTE><BR></FONT><FONT lang=0 = face=Arial color=#000000 size=2 FAMILY="SANSSERIF"><BR>Mike, <BR><BR>What = about the flex of the hammer shank?  When the jack releases, it is no longer = forcing the shank to flex, thus allowing it to spring back into its original form = a nano-second before striking the string.  Couldn't that cause = acceleration of the hammer head?   <BR><BR>Dave STahl</FONT> </FONT></BLOCKQUOTE></BODY></HTML>