Soundboard Edges

[Tony Caught]

Terry

What Del describes is common. Kawai does it inuprights as well.

Tony Caught
Darwin
Australia
caute@optusnet.com.au


----- Original Message -----
From: "Delwin D Fandrich" <pianobuilders@olynet.com>
To: <pianotech@ptg.org>
Sent: Sunday, February 17, 2002 4:43 PM
Subject: Re: Soundboard Edges


>
> ----- Original Message -----
> From: "Farrell" <mfarrel2@tampabay.rr.com>
> To: <pianotech@ptg.org>
> Sent: February 16, 2002 3:29 PM
> Subject: Soundboard Edges
>
>
> > While driving to Mt. Tabot Missionary Baptist Church this morning I had
to
> turn off the radio and try and come to grips with the edges of a new
> soundboard. Let's say you make a 60-foot rib-radiused board (60-foot - the
> radius, not size of the board). OK, so now you have this little dome with
a
> height of maybe 3/8" or so in the middle. (Or maybe you make one with
> smaller radii, so you have more crown - whatever.) The top edges of the
> piano rim and belly rail are at the same elevation - in the same plane.
> -------------------------------------------------------
>
>
> Ron's answer covered most of it, but....
>
> Kimball, and probably others, developed a process to crown their grand
piano
> inner rims to accommodate a spherically shaped soundboard. This has long
> been a common practice with vertical pianos--the soundboard liners are
> crowned to accept the soundboard in a spherical shape.
>
> The soundboard will still be distorted for reasons that will be obvious if
> you think about it a bit.
>
> Del
>