String vibrations (was Re: Stuart)

[Delwin D Fandrich]

----- Original Message ----- 
From: "Phillip Ford" <fordpiano@earthlink.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: September 21, 2003 1:06 PM
Subject: Re: String vibrations (was Re: Stuart)


>
> Leaving aside the preposterous claim that he invented the bridge
> agraffe (perhaps he means that he invented his particular version of
> a bridge agraffe), I read this as saying he believes his system
> causes the string to vibrate only in a vertical plane.

We spent some time working on a virtually identical device at Baldwin
during late 1987 and early 1988. The device worked quite well but we ran
into theoretical problems with it when Engineering became convinced it
would start buzzing some time down the road. Like 20 or 30 years down the
road. We investigated pinning the device to the bridge top, screwing it
down and gluing it down. None of this buzzing was evident in the samples we
tried regardless of how they were attached to the bridge surface, it was
just the possibility of such that made folks nervous. The concern was that
a solid brass block (our samples were machined of brass stock) bearing
against a wood beam that would swell and shrink would eventually come loose
when constantly subjected to vibrating energy from the strings. Nothing we
tried could absolutely guarantee to the powers that be that there would
never, ever, be any problems. I reluctantly had to abandon the project but
I continue to believe it is a good device and I'm glad to see someone using
it.

No patent application was ever submitted. We looked into the possibility
but more experienced heads than mine felt there was sufficient prior art to
preclude a patent being granted and the company was loath to spend the
money to pursue the issue. I expect Stuart found the same situation. At
least I've seen no evidence that he has attempted to patent the device.

Del