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Terry, Dale and all,
From what can be seen, that grand looks like a pretty well thought
out design, with a better distribution of back beams and a generously
dimensioned cross beam. And the brand name is?
Dale wrote;
> Buy the way what is the purpose of the wooden block filling in
>the treble. It looks like it completely eliminated the treble board
>area or is it the picture?
Terry has fitted a treble section cut-off to reduce what I also
regard as excessive sound board area behind the bridge in the treble
section. If you look at the panel-belly rail contact in the top
string section, adequate treble area remains. While it might look to
be less than desirable to those who are used to looking at Steinway
pianos with the board removed, this piano which Terry has worked on
has a main-belly-rail section made from two thicknesses glued
together. There's a lot of belly rail acreage underneath that treble
section of the board.
The belly rail of our 225 piano is similarly constructed, with two 30
mm thicknesses of Rock maple glued together to produce a belly rail
which is effectively a 60 mm thick section of solid maple. The entire
belly rail assembly in our piano is made from Rock Maple, while the
cut-off is made from Australian Antarctic Beech and Silky Beech.
An image of 225 piano no.4 with a 60 mm thick main belly rail
section can be found at;
http://www.overspianos.com.au/ctoff.html
With the Steinway D pianos from Hamburg, the belly rail comprises a
single 30 mm thick section of Red Beech. I suspect that small total
sectional size of this piece is why Steinway glue the key bed to the
belly rail, since it will help what I suspect to be an
under-engineered belly rail to support the sound board.
An image of the '62 Hamburg D case we recently re-boarded can be viewed at;
http://www.overspianos.com.au/stdctoff2.jpg
A similar treble cut-off to Terry's can be seen fitted to this piano.
The laminated bass side corner cut-off reduces considerably the
excessive sound board area of the original design, and the resultant
900 + mm middle order ribs will better resist premature collapse. The
original laminated sound board cut-off and
belly-rail-sound-board-support-beam are made as single bent
lamination, which is a good idea. As with Terry's modified sound
board area, we left the original cut-off in place since it won't do
any harm. Furthermore, it saves us having to insert stiffening
sections across the cut-off fill panel.
The original D's treble-section belly rail design can be seen better
in the following image.
http://www.overspianos.com.au/stdctoff1.jpg
In addition to the treble cut-off, we have fitted an extra back beam
in place of the original 'Steinway bell' to better support both the
belly rail and the hitch plate of the iron plate in the top string
section. With reference to the image and text below, note the
original construction of the belly rail assembly.
The lower piece of the original belly rail is the 30 mm thick main
belly rail beam of European Red Beech (which is also glued to the
keybed of a D). Then there is a 30 mm section of pine or some other
light wood (distinguishable in this image by the visible knott). This
piece is necessary to allow sufficient room in the action bay for
housing the damper levers. This piece is made from Rock Maple in our
piano. Above this we see the laminated Maple/Bubinga mahogany piece
which supports the sound board across the belly. The most surprising
aspect of this design is why Steinway used such a light-weight wood
to join the main Red Beech belly rail span to the Maple/Bubinga
laminate.
Structurally, the belly rail/sound board connection, in all grand
pianos, is already at a strength disadvantage when compared to the
rim, since there is considerable horizontal offset between the main
belly rail member and the belly rail assembly's connection with the
sound board. On this list, much justifiable ridicule has been
levelled at several pianos of Asian origin for using 'select
hardwood' Luaun in the rim, belly rail and back beams. The fill piece
of pine in this concert grand would seem not to be any better when it
comes to material strength. Could it be that since the pine piece
can't be seen in this concert grand once the sound board is
installed, that it found its way into the product as a cost cutting
measure? Surely not!
Happy new year fellow listees,
Ron O.
--
OVERS PIANOS - SYDNEY
Grand Piano Manufacturers
_______________________
Web http://overspianos.com.au
mailto:info@overspianos.com.au
_______________________
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