----- Original Message ----- From: "Ron Overs" <sec@overspianos.com.au> To: <pianotech@ptg.org> Sent: September 08, 2001 6:43 PM Subject: Re: Killer Octave > The problem with leaf springs is that they have hysteresis loss when > compared to coil springs. This is why road trucks can be built > without shock absorbers when leaf springs are employed. The > hysteresis loss of leaf springs would contribute further to loss of > sustain. Isn't this true only when multiple leaf springs are stacked? I've considered using a single wood leaf spring--the spring doesn't care what it's made out of, it's still a spring--coupled to the soundboard with a dowel. The amount of force could be adjusted by varying the amount of bend put into the wood spring. The two advantages I can see to this arrangement are some flexibility in mounting--it's basically a wood beam and you could tailor its characteristics to suit-- and the inherent internal damping of the wood. One of the problems with the coil spring is its lack of damping. Del Delwin D Fandrich Piano Designer & Builder Hoquiam, Washington USA E.mail: pianobuilders@olynet.com Web Site: www.pianobuilders.com
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