<DIV>Ed-</DIV> <DIV>We measured the weight in grams of a lead for the mass (m).  I.e. 14.1 grams for a 1/2 inch lead is usual, then for r we measured the distance of the lead from the middle of the balance hole to the middle of the lead in inches.  So I=14.1X4"  would be for one lead (I just picked a figure 4" for the distance).  Then if there is another lead, do the same for it, adding it to the first lead.  So I=14.1X4" + 14.1X2" (if the second lead is 2" from balance) and so  on.  This gets some figure that sort of arbitrarily represents the moment of inertia, larger in the bass, and graduating to smaller as we go up into the treble.  I think with some research the moment of inertia figure can come to mean something to us.  Empirically finding out what kind of figures pianists like would help set a general standard, I think.</DIV> <DIV> </DIV> <DIV>It seems to me right now if you can get those figures to graduate smoothly you can really even out the feel.  Another question arises as to should we smooth out those figures between the sharps and naturals or let the sharps have a "lighter" number as they naturally do, because of their shorter length.</DIV> <DIV><BR><B><I>Ed Sutton <ed440@mindspring.com></I></B> wrote:</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid"> <META content="MSHTML 6.00.2600.0" name=GENERATOR> <STYLE></STYLE> <DIV><FONT face=Arial size=2>Vince-</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Never having learned calculus, I don't know how to work a formula like this.</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Assuming that I have</FONT></DIV> <DIV><FONT face=Arial size=2>-Strikeweight continuity within Stanwood's suggested range</FONT></DIV> <DIV><FONT face=Arial size=2>-Frontweight continuity within Stanwood's ceiling</FONT></DIV> <DIV><FONT face=Arial size=2>-Even and acceptable DW & UW</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>How can I use this formula to improve action performance?</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Thanks!</FONT></DIV> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV><FONT face=Arial size=2>Ed Sutton</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=madvinmryk@yahoo.com href="mailto:madvinmryk@yahoo.com">madelyn mrykalo</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A title=caut@ptg.org href="mailto:caut@ptg.org">College and University Technicians</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, December 19, 2003 12:56 AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Touch weight</DIV> <DIV><BR></DIV> <DIV> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Hi-<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Of course you can have acceptable DW's & UW's and at the same time have a wide range of moments of inertia, some which may be acceptable and some which may not be.  Or the front weights could be too high.<SPAN style="mso-spacerun: yes">  </SPAN>That's why I don't think UW/DW alone tells us enough about how the action "feels". </SPAN><SPAN style="FONT-FAMILY: Arial"><FONT size=3> <o:p></o:p></FONT></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-FAMILY: Arial"><o:p><FONT size=3> </FONT></o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Here is a formula for moment of inertia</SPAN><SPAN style="FONT-FAMILY: Arial"><FONT size=3> (I):<o:p></o:p></FONT></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><FONT size=3><SPAN style="FONT-FAMILY: Arial; mso-bidi-font-family: 'Times New Roman'"><SPAN style="mso-spacerun: yes"> </SPAN>I= m<SUB>1</SUB>r<SUB>1</SUB><SUP>2</SUP> + m<SUB>2</SUB>r<SUB>2</SUB><SUP>2</SUP> + m<SUB>3</SUB>r<SUB>3</SUB><SUP>2</SUP> + ... + m<SUB>n</SUB>r<SUB>n</SUB><SUP>2<SPAN style="mso-spacerun: yes">   </SPAN></SUP></SPAN><SPAN style="FONT-FAMILY: Arial"><o:p></o:p></SPAN></FONT></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Where m is the mass and r (radius) is the distance that the mass is from the balance hole of the key.<SPAN style="mso-spacerun: yes">  </SPAN>The key itself has some moment of inertia too.<o:p></o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">So the action in question (Wim’s D) might weigh off acceptably (DW and UW), but also may have a too heavy a front weight, and/or moment of inertia.<o:p></o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Stanwood has come up with a good standard of front weights.<SPAN style="mso-spacerun: yes">  </SPAN>Moment of inertia standards are a little more ambiguous at this point. More importantly is that the moments be reasonably smooth from key to key.</SPAN></P> <P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"></SPAN> </P></DIV></BLOCKQUOTE></BLOCKQUOTE><BR><BR>Vince Mrykalo<br>University of Utah<p><hr SIZE=1> Do you Yahoo!?<br> <a href="http://pa.yahoo.com/*http://us.rd.yahoo.com/evt=21260/*http://photos.yahoo.com">New Yahoo! Photos - easier uploading and sharing</a>