Killer Octave

[Delwin D Fandrich]

----- 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