Thanks for W.C.J. and errata

[Ron Nossaman]

Hi all,
For Susan, I'll echo Doug's sentiments on a well done series. Come back soon.

Also, I was looking at the Susan's photos of the M&H screw stringer in the
last edition. The last one of these things I saw was enough years ago that
it was before I became inordinately fixated on soundboards and such, so I
didn't spend much time behind it. <G> Too bad, it's an interesting approach.
The cutoff bars are well placed and the rib feathering should have indicated
to the rest of the industry that the "standard" scoop (scarf?) feathering
wasn't necessarily the only way to go. One interesting thing to me is the
grain direction in the panel. It's nearly perpendicular to the bridge at A4.
The rib fan pattern puts rib #1 within what looks like five degrees of
parallel to the panel grain. This would about have to be a rib crowned board
then, wouldn't it? That is, if there IS any crown at the first three rib
positions. The panel stiffness would be pretty extreme parallel to the ribs,
making this a pretty high impedance board, I would think. How's the ring
time Susan? I did some quick deflection calculations to try to get some idea
of what is happening in the board assembly and I found that, given an
arbitrary 600mm rib length (that's what was already set up in my pascal code
from the last prospecting expedition) a rib 15mm high, and 25mm wide would
deflect the same as a panel 8mm thick and 165mm wide, or 9mm thick and 115mm
wide. The panel in that piano is nearly as stiff as the ribs perpendicular
to the bridge, and it's most flexible roughly parallel to the tenor bridge!
It seems to make that massive bridge look less out of place. Expansion in
the panel with humidity increase would try to pull the bridge back and
*lower* the crown in the center of the board! Very strange indeed. FWIW,
some random observations. 

 Ron