<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <TITLE>Message</TITLE> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 6.00.2800.1400" name=GENERATOR></HEAD> <BODY> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2>Ron,</FONT></SPAN></DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2>Thank you for this very informative post. I appreciate the fact that you took the time to educate us all. This is something that is often not done right from the start and it does improve the playing a lot.</FONT></SPAN></DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2>Thanks again,</FONT></SPAN></DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2>Marcel Carey, RPT</FONT></SPAN></DIV> <DIV><SPAN class=937271212-11112006><FONT face=Arial color=#0000ff size=2>Sherbrooke, QC</FONT></SPAN></DIV> <BLOCKQUOTE dir=ltr style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px solid; MARGIN-RIGHT: 0px"> <DIV></DIV> <DIV class=OutlookMessageHeader lang=fr dir=ltr align=left><FONT face=Tahoma size=2>-----Message d'origine-----<BR><B>De :</B> pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] <B>De la part de</B> Ron Overs<BR><B>Envoyé :</B> 11 novembre 2006 02:04<BR><B>À :</B> Pianotech List<BR><B>Objet :</B> Re: Sustain pedal lift ratio<BR><BR></FONT></DIV> <DIV align=center> </DIV> <DIV><BR></DIV> <DIV>The pedal/damper lift ratio is calculated using the following formula.</DIV> <DIV><BR></DIV> <DIV align=center>(A/B) X (C/D) X (E/F)</DIV> <DIV><BR></DIV> <DIV>For many damper systems, the push rod will come through the keybed to contact the damper tray almost directly under the damper wire flange. In these instances you can disregard the lever lengths F and E, giving them a value of 1. There will be some small variation in the actual ratio due to variations in the lever angles from piano to piano. However, the variation is too small to worry about in practice with respect to the ratio, but the lever angles are critical with regard to friction.</DIV> <DIV><BR></DIV> <DIV>If the push rod is fitted with guide pins the angle of the push rod, with respect to the damper tray and damper lever, won't be of much consequence, since it will contribute very little friction. The damper lever under the keybed is a different matter. I prefer to set this lever so that it is horizontal at half damper lift. This arrangement will minimise friction between the lever and the lyre push rod. For our own 225 piano, we machine away the lower-half of the damper lever thickness where it meets the push-rod capstan, and lengthen the lyre push-rod so that the lever is horizontal at half damper lift. This results in less friction and less likelihood of squeaks developing between the lyre push-rod capstan and the lever bearing-felt.</DIV> <DIV><BR></DIV> <DIV>I hope you have found the above mini-doc to be useful, since this is the first time I've written-up the procedure onto something more substantial than a piece of scrap of paper around the workshop. However, its been good for me to document the procedure.</DIV> <DIV><BR></DIV> <DIV>For those of you who would like to know how I produced the graphic and imported it into the Eudora programme, here is the procedure.</DIV> <DIV><BR></DIV> <DIV>1) Draw the graphic using my old 2D CAD programme.</DIV> <DIV>2) Capture a screen image of the drawing and save it to the desktop as a TIFF file.</DIV> <DIV>3) Open the TIFF file in Photoshop, resample, reduce in size and save as a jpg file.</DIV> <DIV>4) Drag the jpg file into the Eudora email document.</DIV> <DIV><BR></DIV> <DIV>Ron O.</DIV><X-SIGSEP><PRE>-- </PRE></X-SIGSEP> <DIV><FONT face="Times New Roman" color=#0000ff size=+1><B>OVERS PIANOS - SYDNEY</B></FONT></DIV> <DIV><FONT color=#000000><I>   </I></FONT><FONT color=#0000ff><I>Grand Piano Manufacturers</I></FONT><FONT color=#000000><BR>_______________________</FONT></DIV> <DIV><FONT color=#000000 size=-2><BR></FONT><FONT color=#000000>Web http://overspianos.com.au</FONT></DIV> <DIV><FONT color=#000000>mailto:ron@overspianos.com.au<BR>_______________________</FONT></DIV></BLOCKQUOTE></BODY></HTML>