Broads

[Richard Brekne]

Hi folks.

Well, I finally got around to opening up my 1836 (methinks) Broadwood
that I will be attempting to put back together and I have a few
questions  I'd like to have some answers to. Number 1 and first and
formost... Was there any real crown built into the sound boards of these
things. I will describe what I have in front of me as best I can.

Sitting at this square piano and looking over the more or less
triangular shaped sound board from that angle, you see the grain moving
off at about 45 degrees.  There are ribs going at about 20 degrees, not
exactly all that much across the grain, and these lengths are broken by
three ribs that run straight out at 90 degrees which are found right
under the bridge area.  Am I mistaken here or would this do little or
nothing to balancing cross grain and with grain stiffness ? Certainly
doesn't seem like a recipe for a compression crown in any case.

The Bridge has that typical reverse in direction relative to sound board
grain for these... and in this the greater part of the bridge is more or
less at right angles to the grain, except in the treble area after where
it swings around and follows the grain. What was that discussion about
mass in the treble rim and stiffness in the bass rim ? There is also a
coupling from the board to the pin block in this area, presumably to
address both mass and stiffness.

So... back to the original question. Are these boards meant to be
basically flat ?. Strings come off tomorrow and I can give you some more
info about what observable crown there is (real difficult to ascertain
from underneath here) and what down bearing looks like.

Thanks for any advice / observations.

RicB

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no