RC&S question in general Kent

[Richard Brekne]

Hi Kent   

    Your "bold faced fact" appears to be an opinion to me, an opinion
    based on your analysis of the available data and evidence. Others
    looking at the same data and evidence, myself included, might reach
    a different opinion.

    Kent Swafford

Of course we all have the right to draw whatever conclusions we want.  
But  lets back off from unnecessary extreme positions. These discussions 
are supposed to enlighten us about how different  approaches function.  
The whole... <<which is better>> thing is nothing more then a 
destructive side track.  Who is discouraging who in all this ?   
Disputing the validity of RC and CC methods is no more productive then 
some of the discussion tactics just used... or throwing out presumably 
lightly meant death threats. How does any of this answer any of the 
questions on the table or provide deeper understanding into the various 
methods different builders use and have used to build the instrument we 
all love and have devoted our lives to servicing ? 

Take this residual crown bit as an example. The query was clearly 
qualified as including two other known states... Rib dimensions and 
amount of panel compression at glue up MC. Before going on please let me 
point you to the following very short post from Ron Nossaman.

    http://ptg.org/pipermail/pianotech.php/2008-January/216274.html

So I asked...given the aforementioned qualifying conditions  how much 
compression a given downbearing will impart into the soundboard for a 
given deflection... ie. for what ever target residual crown there is 
after downbearing is applied. The post I just directed you to clearly 
conflicts with the flurry of responses I got declaring that residual 
crown is meaningless.  Despite going out of my way to re-underline the 
conditions I set... which are perfectly inline with Rons post I linked 
to above... I got the usual ration. Grin... and on top of that.. there 
are actually exacting predetermined amounts of this same residual crown 
calculated on when designing and RC&S board for any given scale. Its 
nearly half of the whole design approach !

Now where is the constructive learning spirit in all this ? What ends 
are served ?

I'd restate my question... but it seems like really no one knows how to 
figure how much compression is imparted to a panel for a given 
downbearing with known starting values for rib strength and orientation 
and panel compression for a constant RH.    And if THAT be the case... 
then how on earth can we be certain of just how much compression is in 
an RC&S panel when loaded ? Those ribs are stiff suckers... downbearing 
forces compression in the panel as it strains against the ribs.... its a 
fair question.

Why don't we drop all this judgmental stuff and get down to what this 
list is supposed to be about.  I'm just asking questions I want straight 
and respectful answers too.  Is that such a problem ?

Cheers
RicB


    On Jan 28, 2008 1:55 AM, Richard Brekne <ricb at pianostemmer.no> wrote:

     The fact is...and this is a bold faced fact... that experienced
    manufacturers have been building boards of all types for 300
    years... and there is no statistical grounds for doubting  the
    viability of any of the basic methods employed (when done so
    appropriately) today .