[pianotech] Belly talk

[Dale Erwin]

Jim
 Nick is making a rib crowned board of some kind...right Nick?  
 Most of the time I am talking about a rib crowned system dried to no more than 5.5 %. or 6% depending on where it goes
I also make rib crowned and supported boards. Both have styles have far more initial crown than C.C. boards.
Apples, oranges, apples , oranges...bananas?.... I like em all 


One difficulty in this discussion is that Nick is (correct me if I'm 
wrong, Nick) talking about a CC system, and I am talking about a Rib 
crowned system. I think Dale may be referring to a hybrid system.  If we 
talk of 3 different structural systems as if they are the same 
structural system, thing get mushy...an apples and oranges thing.


Jim Ialeggio


Dale Erwin R.P.T.
Erwin's Piano Restoration Inc.
 Mason & Hamlin/Steinway/U.S. pianos
www.Erwinspiano.com
Phone: 209-577-8397

 
  





-----Original Message-----
From: Jim Ialeggio <jim at grandpianosolutions.com>
To: pianotech <pianotech at ptg.org>
Sent: Sat, Dec 1, 2012 12:39 pm
Subject: [pianotech]  Belly talk


HI Dale

< In the case cited the piano in question was an Stwy A-2 and having 
done quite a few A-2s both ways...

Right. This is where the complexity of the system in general and each 
individual belly comes into play.  I can see a reasoning why the sound 
might be a little different between the single and double crown, but I 
really don't think I would attribute it the 3 dimensionality of the 
system as Nick is suggesting. Rather I could see it as distributing the 
tail "bend down" in a more evenly trended fashion across more of the 
long bridge rather than localized at just the tail.

I used to attribute more stiffness to the shape of the crown itself. But 
after watching these things behave in and out of the piano the crown 
shape in and of itself, at least in a minimally compressed rib crowned 
board, really does not seem to be doing much in and of itself. As I say, 
this was not my opinion originally but it certainly is where I'm going 
right now..at least until suppertime<G>. However, to be clear my opinion 
is being formed regarding the RC&C structure in particular, not a 
compression system.

One difficulty in this discussion is that Nick is (correct me if I'm 
wrong, Nick) talking about a CC system, and I am talking about a Rib 
crowned system. I think Dale may be referring to a hybrid system.  If we 
talk of 3 different structural systems as if they are the same 
structural system, thing get mushy...an apples and oranges thing.


Jim Ialeggio

-- 
Jim Ialeggio	
jim at grandpianosolutions.com
978 425-9026
Shirley Center, MA


 
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