More CC vs RC questions was RE: Killer Octave & Pitch Raise

Richard Brekne Richard.Brekne@grieg.uib.no
Tue, 15 Feb 2005 21:24:06 +0100


Hi Sarah..

Another idea would be to construct a CC board with under dimensioned
ribs... with respect to height... and when its taken on crown 
laminate
these same ribs with pre crowned ribs to bring the ribs to the 
desired
dimensions.  One places then the underside flange of the rib 
glued to
the soundboard under tension (tho it is already under compression 
being
bent from the soundboard) and the upwards side of the machine 
crowned
<<laminate rib>> under compression. But since wood can handle 
much more
stress along the grain... the darn thing should end up pretty 
strong.
The piece of the rib glued to the soundboard would be bent and 
tensioned
by the soundboard, and held in place by both the compression in both
soundboards  and the second rib layer. In addition since the 
second rib
layer was machine crowned it would also contribute to supporting
downbearing in the sense an RC&S set of ribs do..

Lots of combi board systems available if you first want to try.  Pre
crowned laminant ribs have already been used.. tho not in the 
sense above

Cheers
RicB



What I was thinking when I suggested a hybrid board was literally 
two panels
fitted together.  Imagine a CC board from, say, the lower treble 
downwards,
ending at a half-rib (split lengthwise, that is).  Join that 
half-rib to the
half rib at the edge of a RC/S board for the lower treble and 
upwards.  That
would give the longevity of crown and higher sustain in the 
problem areas,
with acoustic coupling that would give the entire board some
damping/hysteresis/distortion properties of the CC board, if only 
by virtue
of the fact that vibrations would bleed back and forth across the 
board
joint.  It might yield a classic CC sound with most of the 
benefits of RC/S.
Perhaps???

Peace,






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