Ed: There is as well a phenomenon called duplex metal deformation which is a tension/compression condition caused by the bending of the wire around a curved surface. There is a period of time in which the differential tension/compression as well as the friction vectored toward the contact of the wire with the pin is in movement and equalizing. View full size Aside from the math of this which is not really so daunting, this occurs at all major wire bends against surfaces, particularly tuning pins and hitch pins. Paul -----Original Message----- From: A440A at aol.com To: pianotech at ptg.org Sent: Fri, 18 Apr 2008 9:49 pm Subject: Re: stretching wire -- an anecdotal analysis Kurt asks: << Granted, this sounds reasonable, but why should such tightening of the slack in the coil happen slowly? What is the physical mechanism that causes this type of pitch drop to be time release? >> I assume it is the friction around the tuning pin which is slowly allowing the stress in the wire to overcome it. Anybody got any other ideas? Ed Foote RPT http://www.uk-piano.org/edfoote/index.html www.uk-piano.org/edfoote/well_tempered_piano.html <BR><BR><BR>**************<BR>Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos.<BR> (http://autos.aol.com/used?NCID=aolcmp00300000002851)</HTML> -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080418/edaf4efb/attachment.html
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