<HTML style="FONT-SIZE: x-small; FONT-FAMILY: MS Sans= Serif"><HEAD> <META http-equiv=Content-Type content="text/html;= charset=iso-8859-1"> <META content="MSHTML 6.00.2900.2627" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff>I'm with you...a 100 cent change hardly= moves the pin at all...<BR><BR>David= Ilvedson<BR><BR><BR><BR><BR> <DIV style="PADDING-RIGHT: 5px; PADDING-LEFT: 5px;= PADDING-BOTTOM: 5px; BORDER-LEFT: #000000 3px solid;= PADDING-TOP: 5px"> <HR> Original message<BR>From: Farrell= <MFARREL2@TAMPABAY.RR.COM><BR>To: Pianotech= <PIANOTECH@PTG.ORG><BR>Received: Wed, 11 May 2005 21:18:17= -0400<BR>Subject: Re: Grist for the Mill<BR><BR> <DIV align=left><FONT face=Arial>A 30 degree turn of a tuning pin= every year on a stable piano? No way!</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Calculate the pitch increase with a 30= degree rotation on a 2/0 pin - even the 7.5 degree= rotation - I suspect you will very quickly realize your= numbers are grossly excessive.</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Unless, of course, I am wrong. But I don't= think so.</FONT></DIV> <DIV><FONT face=Arial></FONT> </DIV> <DIV><FONT face=Arial>Terry Farrell</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=tune4u@earthlink.net= href="mailto:tune4u@earthlink.net">alan and carolyn barnard</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> Wednesday, May 11,= 2005 8:50 PM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Grist for the= Mill</DIV> <DIV><FONT face=Arial></FONT><BR></DIV> <P> <DIV>We recently had a long dialog on here about the actual= changes in a piano that has gone flat. There was much poo-pooing= (can we say that on TV?) from some folks of the notion= that tuning pins turned counter-clockwise when pianos go= flat. Their arguments were logical and some folks even= produced mathematics to demonstrated that pin reversal is= unlikely.</DIV> <DIV> </DIV> <DIV>BUT ...</DIV> <DIV> </DIV> <DIV>I was thinking about this on my way home from PTG chapter= meeting (2.5 hr drive) and came up with a little point of logic= which suggests that the pins MUST move. See what you think= ...</DIV> <DIV> </DIV> <DIV>Virtually all pianos go flat over longish time periods and= certainly are found flat more often than sharp if you go through= a whole cycle of season changes, i.e., an annual tuning. When= we bring a flat string up to pitch, it tends to increase= the width of the coil slightly every time we turn the pin. If= the pin is turned one full revolution--360= degrees--over years of tuning, this would add the thickness= dimension of the wire to the overall coil width and one= full wire wrap to the number of coils. </DIV> <DIV> </DIV> <DIV>You with me?</DIV> <DIV> </DIV> <DIV>So let's take a hypothetical piano string--say a very stable= 1905 Howard upright A4 middle string--that has averaged (let's= be conservative...) falling flat enough that a 7.5= degree turn of the pin was required each year to bring it= up to pitch. Now 7.5 degrees is a fairly small= annual adjustment, just a little tweak, actually. Ce n'est= pas? It's only 1/6 if a quarter turn.</DIV> <DIV> </DIV> <DIV>So, between 1905 and 2005, we have turned that string's= pin 100 X 7.5 = 750 degrees, more than two full= turns.</DIV> <DIV> </DIV> <DIV>How many old pianos do we run into that have five or more= coils on the pin? I never noticed any.  In fact,= most seem to have the original 3 coils standing about as far= from the plate as the day it was strung--unless someone has= hammered them in, in which case it's still only about 3= coils!</DIV> <DIV> </DIV> <DIV> <DIV>Pause ... thinkin on that?</DIV> <DIV> </DIV> <DIV>Now strings must become ever so slightly thinner as they= stretch, especially in the earlier years. So, for the string to= produce the same pitch, the string tension required would be= ever so slightly less over time. This would have a very slight= mitigating effect on the thought puzzle proposed above. But= nowhere near enough to explain 100 years of flatness, methinks.= And ven if the string is stretching, you would still be adding= linear length to the coil every time.  <DIV> <DIV> </DIV></DIV></DIV> <DIV>I believe, in fact, that about a 30 annual correction, or= more, would be very common.  Think about your own= real-world, real-piano experience. Visualize pulling= your tuning hammer through a 30 degree arc, i.e., 1/3= of a quarter turn. That's still a pretty darned small= once-a-year adjustment. So, I think my estimates here have= been very, very conservative.</DIV> <DIV> </DIV> <DIV>Anyway, at 30 degrees the piano would have to have= a total of 8+ full coils on every pin if the pin never turned= backward.</DIV> <DIV> </DIV> <DIV>Your turn or, as we used to say in Viet Nam .... I n c o m i= n g ! ! ! </DIV> <DIV> </DIV> <DIV>Alan Barnard</DIV></DIV> <DIV>Hunkered in the Bunker in Salem, MO</DIV> <DIV> </DIV> <P></P></BLOCKQUOTE></DIV></BODY></HTML>