<!doctype html public "-//W3C//DTD W3 HTML//EN">
<html><head><style type="text/css"><!--
blockquote, dl, ul, ol, li { padding-top: 0 ; padding-bottom: 0 }
--></style><title>RE: Schiedmeier Pianos and under bridge
structure</title></head><body>
<div>At 6:36 am -0700 6/7/07, David Love wrote:</div>
<div><br></div>
<blockquote type="cite" cite>The only issue about whether this really
contributes to stiffness is that<br>
the underside bridge structure is tunneled out, as it were, in order
to<br>
allow the ribs to pass through the structure untouched. While
there remains<br>
a thin piece of wood below the rib at those points, I don't imagine
there is<br>
much stiffness to the overall structure. I don't know if I'm
painting a</blockquote>
<blockquote type="cite" cite>very clear picture. The piano, btw,
has more than adequate power.</blockquote>
<div><br></div>
<div>Here is a picture of the Grotrian, which is the same. If
you want to find out how stiff the structure is in spite of the the
tunneling for the ribs, cut some tunnels like that in a piece of 1 x 1
and glue that to a flexible 1" lath. You will discover the
result is not much less stiff than if you had not cut the tunnels,
just as square tubing and I-beams are stiff without the need for the
hollows to be filled. An engineer would be able to tell you
exactly how much difference it makes and the maths that determines
it. If added mass were the function of the under-bridge, they
would not need to go to the trouble to make it like this.</div>
<div><br></div>
<div>Unfortunately it was the end of a tiring day when I remembered to
take the pictures and I forgot to measure the heights of the bridge
below and above the soundboard, but I reckon the total height
excluding the soundboard must be nearly 55 mm, probably equivalent to
a standard bridge about 50 mm high. As I said, the Grotrian
bridge is also unusually wide. My feeling about Grotrians of
this period has always been that they are _too_ stiff.</div>
<div><br></div>
<div>JD</div>
<div><br></div>
<div><br></div>
<div><br></div>
<div><img src="cid:p0624081bc2b441b7e7eb@[10.0.0.1].1.0"></div>
<div><br></div>
<div><img src="cid:p0624081bc2b441b7e7eb@[10.0.0.1].1.1"></div>
</body>
</html>