<HTML><HEAD> <META charset=US-ASCII http-equiv=Content-Type content="text/html; charset=US-ASCII"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR></HEAD> <BODY style="FONT-SIZE: 12pt; FONT-FAMILY: Arial; BACKGROUND-COLOR: #ffffff"> <DIV> <DIV>In a message dated 2/4/2008 6:31:22 PM Pacific Standard Time, a440@bresnan.net writes:</DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT face=Arial>you can directly measure the hammer movement that results from key movement.<SPAN style="mso-spacerun: yes"> </SPAN></FONT></BLOCKQUOTE></DIV> <DIV><FONT face="Bookman Old Style">This can be useful information, to be sure, when doing action trouble assessment. However, action ratio measured in this way is not exact, as the ratio changes during the stroke, due to changing contact points between the hammer and wippen, rolling of the capstan/heel contact, changes of the contact point at the balance rail punching, etc. The hammer movement at 6mm key travel will not always be twice what it is at 3mm. This is why I like just to regulate a sample note completely, using 1.75 blow, and see what kind of dip it produces - it just eliminates the complications, seems more straightforward, and takes very little time. (1.75 blow barring indications otherwise, like the shank winding up way off the cushion). Then I can decide whether to compromise the hammer travel or the key travel; and what the ramifications are for hammer head weight and action inertia.</FONT></DIV> <DIV><FONT face="Bookman Old Style"></FONT> </DIV> <DIV><FONT face="Bookman Old Style">Actually, it makes sense to set up a note at or near each end of the keyboard. The key ratio is not always the same from one end to the other, even on "precision" pianos. I regulated a Yamaha C7 on which the ratio was noticeably different end to end, and have found the same on other good makes.</FONT></DIV> <DIV><FONT face="Bookman Old Style"></FONT> </DIV> <DIV><FONT face="Bookman Old Style">Bob Davis</FONT></DIV><BR><BR><BR><DIV><FONT style="color: black; font: normal 10pt ARIAL, SAN-SERIF;"><HR style="MARGIN-TOP: 10px">Who's never won? <A title="http://music.aol.com/grammys/pictures/never-won-a-grammy?NCID=aolcmp00300000002548" href="http://music.aol.com/grammys/pictures/never-won-a-grammy?NCID=aolcmp00300000002548" target="_blank">Biggest Grammy Award surprises of all time on AOL Music.</A></FONT></DIV></BODY></HTML>