Quote, then comment: >Date: Fri, 10 Dec 2010 10:09:31 -0700 >From: Fred Sturm <fssturm at unm.edu> >Subject: [CAUT] damper touch weight >First, there is quite a bit of force needed to push trichord dampers >out of the strings - as much a 5 gm. Even when trimmed nicely and >precisely to the bottom of the strings there is a significant >amount, though the difference between well-trimmed and not trimmed >is noticeable, Fred's observation is interesting, though inconclusive. He does have the means, if not the time, to pursue this more thoroughly. I hope he does. Otherwise, I'll have to copy his jig (or rent one) and do it myself. Horrors! The variables to isolate are numerous: - qualities of particular felt (fiber length, density) - grain orientation - shape - configuration (tri-tri or tri-flat) - weight of head/lever (including any springs) - distribution of friction source (pinching middle string vs outward displacement of outer strings) - side bearing (as he said) - and likely more While this additional moment of resistance may be measurable, given where in the keystroke this particular aspect of damper lift engages, I find it hare to believe that, within the parameters of enlightened design and execution, it can be as significant to the friction profile as the pinning, knuckle issues, or damper assembly mass/spring irregularities that have been discussed. It's still interesting and thoroughly gauge-worthy. At 04:35 PM 12/19/2010, you wrote: > >... since more force is needed to push trichord dampers out of the >strings even after trimmed would it be possible to rub some Teflon >powder on the felt or another lubricant to help reduce the force? > >Regards, >Jack Houweling I'm guessing that's a NO. It might work if there were an extended period of sliding friction between the damper felt and string, but if that were the case, the design or execution would be incorrect (unless that was the effect being sought). I'm assuming that there is no oxidation on the string at that point. I'd also be concerned that the introduction of such treatment could have a deleterious effect, either by the process of application, or residual effects of substance compacting. Seasons - David Skolnik Hastings on Hudson, NY > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20101220/19d97be3/attachment-0001.htm>
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