laminated ribs

[Ron Nossaman]

> One question I have is why, if you want to create a higher design loaded
> board, do you need to increase the bearing?  On an RC&S board, with little
> change in tone coming from modest changes in bearing, isn't it enough to
> simply stiffen the assembly with the same residual bearing?  The difference
> would be, I assume, the amount of deflection.  But if the panel deflects 30%
> instead of 50% is that a problem tonally?  Wouldn't you have the same net
> tonal effect without having to increase the actual bearing load on the
> board?  
> 
> David Love


It might. Design load isn't my concept, and isn't where I 
start with design. My intent isn't to accommodate a higher or 
lower  design load, but to provide adequate bearing that, if 
the board sinks out somewhat over the years, there will still 
be adequate bearing left. Same with crown, to maintain the 
opposing spring system of string and soundboard even with some 
long term settling. I'd like to think that as well as sounding 
good to me now, they won't end up with a zero bearing negative 
crown killer octave some day, and will sound good to me for a 
very long time. Time will eventually tell, one way or another, 
but that's one of the factors I consider. This stuff is still 
relatively new to me, and I don't pretend to know the details 
of all possible combinations, which is why I continue to 
explore and learn. In five years, I may still be loading them 
like this, or I may not, depending on what I've learned in the 
interim.

Part of the equation in determining all this is beam 
clearance, which puts limits on rib depth, crown radius, and 
loading. You pick your set of ranges for variables, juggle as 
you think will take you farther in the direction you want to 
go, and prove or disprove the hypothesis by stringing the 
sucker up and hearing how you did. I'd love it if someone 
threw large quantities of money at me to explore this stuff 
systematically in much greater detail at higher speed, but I'm 
a one man shop with a tuning clientèle, with the need to make 
a living in there somewhere. Otherwise, I'd be fearless. I 
hate it when necessity interferes with fun, ya know?

Bummer.

Ron N