<!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 6.00.2600.0" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#d8d0c8> <DIV><FONT size=2>Stephane:</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Thanks for catching that, yes I meant increase the = blow distance to reduce aftertouch.  </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Good aftertouch has to do with jack clearance from = the knuckle when the key is fully depressed.  More than 1.5 mm is unnecessary.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>I don't like to alter the angle of the jack relative = to the knuckle, but I see it happening on vintage NY Steinways that go to 17mm knuckles.  Though in that case the knuckle will incline toward the = hammer more, whereas by increasing the spread, the jack will incline toward the = hammer flange more.  I suppose in making the choice between spread and = blow it would depend on how much deviation is necessary.  I don't like to = lengthen the blow excessively.  It adds weight to the action and creates a = feeling of lack of control.  Also, if the action ratio is so high that you = are significantly compromising regulation, then it might be worth assessing = the weight and balance as well.  Higher action ratio not only means = shorter dip, or longer blow, but, more importantly, poorer force = leverage.  In short, anything you do will be a compromise, so you just have to try = some samples and see how it works.   If you can't get it to = regulate the way you want, further analysis of the placement of the capstan/knuckle = might be in order.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>David Love</FONT></DIV> <BLOCKQUOTE dir=ltr 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=collin.s@skynet.be = href="mailto:collin.s@skynet.be">Stéphane Collin</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> September 16, 2002 3:06 = AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Bechstein grand = spread dimension,</DIV> <DIV><BR></DIV> <DIV><FONT face=Arial size=2>David,</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Just two questions.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV><FONT size=2>Action ratio is equal to </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2><U>blow distance - letoff</U> </FONT></DIV> <DIV><FONT size=2>key dip - after touch </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>By increasing the spread you will lower the = action ratio.  A lower action ratio will mean that the piano will = require deeper dip.  Or, in your case, you will have less aftertouch.   Before doing this, you will have to make = sure that altering the spread doesn't create other problems especially in = terms of jack/knuckle alignment.  </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>The other alternative is to reduce the blow distance.  </FONT></DIV> <DIV><FONT size=2></FONT> </DIV></BLOCKQUOTE> <DIV><FONT size=2>If I follow you, didn't you mean increase the blow = distance (in order to reduce the aftertouch for the same key dip and same = action ratio) ?</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Can I ask you how you define a good aftertouch ? = By feel at the key ? by precise measuring (at the key or at the jack) ? = </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>And indeed, do you feel it is more important to = keep good alignment between jack and knucle core, and therefor altering = preferrably the hammer blow ?</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Thanks for your expert advises.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Stéphane = Collin.</FONT></DIV></BLOCKQUOTE></BODY></HTML>