More on soundboard crown

[Richard Brekne]

---------------------- multipart/alternative attachment
Hi folks

Ok... this round has been full of good stuff, and I have been really enjoying
sitting back and reading Phils input and the responses it has generated.
Reading back a bit to review... this quote from one of Nossamans posts stuck
out at me...


     snip.... Given a panel crowned assembly with a severely dried
     panel, and one rib crowned with a non dried panel, both to identical
     crowns
     at room EMC, the one with the higher panel compression level will
     have the
     steeper spring rate gradient, and will be stiffer.

Now correct me if I am wrong.. but I understand this to mean that a CC board
will be stiffer, both unstrung... and increasingly so when downbearing is
applied.  Assuming that is correct, and putting aside all other compression
damage discussion for a second or two... I have a question about this long term
so called compression set. Given the absolute ideal climatic conditions over
many years... would a soundboard subjected to uniform compression set take on a
permanent stiffness as a result of that, or is it exactly the woods resistance
to being compressed that causes the stiffness ? Seems to me I also read
something in one of Johns posts that hinted in this direction. That a CC board
<<properly treated>> will eventually be pressed into a very stiff and permanent
condition.

On the side of this... and please forgive whatever lack of knowledge I display
in the asking,  if compression from ribs being glued cross grain to the panel
is such a problem...even in RB boards.. is there no way of contriving a rib
such that it is a bit less constraining ?

Just musing again

RicB

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html
http://www.hf.uib.no/grieg/personer/cv_RB.html


---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/d4/ee/73/80/attachment.htm

---------------------- multipart/alternative attachment--