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Happy New year Ron
Great to hear from you & good of you to remove your head from the piano
long enough to post. It's always good to see what's up/new
Good Post & enjoyed the design in the pics. Beautiful work. I especially
liked the ideas about the beams & belly needing more stiffnes from the maple
ones you installed.. This makes a great deal of sense to me. In hind sight what
doesn't make sense is so much goes into a fine laminated rim in some
American pianos & then the belly rails so weak due to laminated softwoods. This has
been in my mind for a while now. I'd truly Like to here the 225 in the
picture. After all design is great when the end result produces a sound
never/rarely heard before. I should think that a piano so constructed should sustain
for a very long time in every register with tonal color to live for.
Is this so?
Looking at my Mason double A project I notice just how toooo much board
is behind the bridge. Its' simply cavernous. It's not to late to put in a fish
This has got me thinking again. Is there a percentage of board to remove
formula that seems usual?
Thanks & Blessings
Dale Erwin
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.
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