Stephen Birkett had some videos up on string motion and damper action. I think it was taken at something like 2000 fps but it was quite some time ago. I don't know if the videos are still available or not. They were interesting. dp David M. Porritt, RPT dporritt at smu.edu -----Original Message----- From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of David Stanwood Sent: Monday, December 20, 2010 9:40 AM To: caut at ptg.org Subject: Re: [CAUT] damper touch weight - head-weight preference? >On 12/20/2010 8:04 AM, David Skolnik wrote: >>Del - >>The reason is probably obvious, but the mind rebels. Why? >>David Skolnik >>Hastings on Hudson, NY >> >> >>At 09:06 PM 12/10/2010, you wrote: >>>And you'll find the dampers will work better with less overall weight >>>if you >>>put it all up in the damper heads and take it all out of the levers. >>> >>>ddf > > >A couple of reasons, short version. With the vertical excursion of >the string, the bends in the wire provide some compliance that >reduces the effectiveness of the weight in the under lever. Then, >the horizontal component of the string excursion isn't served at all >by the weighted under lever. Put the lead in the head (yea, I know), >and the mass more efficiently couples to the strings. > >Ron N I was going to wait for Del's answer but what the hay... I've always imagined that the string vibrations move the damper head... more mass in the damper head would tend to absorb this movement and increase damping, especially in the sideways mode.. hope this is clear... Has anyone seen high speed film of damper heads damping? Does the head get thrown sideways by the movement of the string? David Stanwood
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