help a beginner measure mc in wood with confidence

jimialeggio5 at comcast.net jimialeggio5 at comcast.net
Thu Aug 21 06:35:08 MDT 2008


ROn and Dale,

I understand and am on board(no pun intended) regarding relative crown stability 
of pianos with RC&S boards..

Let me go back and try to be more clear on what my questions were. Here are 2 
questions, and I'll reference my original statement/question.

1-The point of  my copy here:

"I'm doing RC&S boards...5% is not in my repertoire. For downbearing 
measurement, 
I'm shooting for around 7-7.5%mc.  Both yourself and Ron seem to be saying the 
crown of an RC&S board is not variable at different mc's.  I'm chicken and will 
have to prove that to myself before I trust it."
 
was one of procedure.  

So my question reflects this procedural issue; 

IE, Is the stability of the RC&S crown such that (in an RH variable shop) mc of 
the board, when taking downbearing measurements, is not important and verifying 
mc with some mc reference is unnecessary?

2-The point of this copy:

"But one other mc frustration I have is that after all is said and done, the 
board ribbed, in, downbearing done, strings up to pitch, I want to come back and 
observe exactly what I have achieved for future reference. IE, have the "as 
built" deflections hit the target crown deflections of the design. Not knowing 
what the mc of the board at this point is, to me, adding a variable which I want 
would really like to exclude."

was similar to above.  

IE. are you saying that measurements of crown,  to verify (for 
future use), what your as-built loaded crown deflection was as compared to your 
designed loaded crown deflection, can be taken without  regard to the mc of the board at that 
point, because of the stability of the RC&S crown.

Hope my question is clear-er-er
--
Jim Ialeggio 
www.grandpianosolutions.com
Shirley, MA (978) 425-9026


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