they don't tangle into one giant permanent spring in the bag. to keep them from being tangled, I think there was a tech tip to put them all on a pipe cleaner. Wim -----Original Message----- From: Ron Nossaman <rnossaman at cox.net> To: pianotech at ptg.org Sent: Thu, Mar 11, 2010 12:18 pm Subject: Re: [pianotech] Jack Springs John Ross wrote: It is from Schaff, item number 527A, upright jack spring. > The physical properties are equal taper from top and bottom, to a > compacting of a couple of coils, in the centre, like each end. > The old springs were a double at each end, and the winding went wider in > the middle. John, I haven't used any of these yet, but there was a Journal article (don't know when) on how the design was arrived at. There's less torsion stress on the wire because there are more coils within the compression range, pretty much eliminating breakage and producing a more constant spring rate, and they don't tangle into one giant permanent spring in the bag. I don't see a reason they'd be noisy, but I don't really know. I'd try them. Ron N -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100311/b69483b1/attachment.htm>
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