Baldwin SD-10

[Delwin D Fandrich]

----- Original Message -----
From: "Ron Nossaman" <RNossaman@KSCABLE.com>
To: <pianotech@ptg.org>
Sent: September 05, 2001 8:00 PM
Subject: Re: Baldwin SD-10


> >The soundboard was designed to leave it approximately 5/8" short of the
> >outer rim all along the perimeter. The rationale, if I remember
> >correctly, was to give the sound board room for expansion or contraction
> >depending on the season. There is no 'channel' per se; just a gap between
> >the soundboard and the outer rim.
>
> 5/8"?!!!!!!!!!!! That's a pretty substantial allowance for an
approximately
> 8 mm panel that 's glued to the inner rim!! I'd sure like to hear where
> this much expansion is going to come from.

There isn't that much expansion. The 5/8" gap makes it some easier to fit
the soundboard to the rim. If there were only a 1/8" gap you would easily
notice any irregularities. With a 5/8" gap you don't notice them.



> > The ribs are supposed to have a
> >little clearance from the top of the inner rim. They are designed to
> >'float' to the edge of the soundboard without contact with the rim.
>
> Why?

The gap makes it some easier to fit the ribs to the rim. If they were a
size-on-size fit it would be necessary to accurately control the depth of
the notch and the height of the rib at the end of the feather. By making the
notch deeper than the rib will ever be there is no need to 'fit' anything.
And, as you point out, neither is there any acoustical need to do so.
Acoustically the damage is done when the rib crosses over the edge of the
inner rim anyway. And this way Marketing can claim notched-in ribs without
forcing the factory workers to waste much time on the process. It works.

Del