The treble end of the long bridge is very near the clamped edge of that long "beam" of bridge and long grain. Set up an old yard stick, which is probably made out of spruce that should have been held in reserve for future soundboards in the first place, and support it under each end to use as a beam. Put a stack of washers or whatever handy weight you have at hand, at the 30" mark and note the deflection. Now move the weight to the 1" mark and again note the deflection. The board is effectively stiffer in the treble, close to the edge, than it is in the low tenor and bass considerably farther from the edge. Ron N Ron, You make a good point here about the very top end of the bridge being near the end of the 'beam' and the beam being stiff there. I did a quick check of deflections along the grain assuming the 'normal' grain orientation and an orientation 90 degrees to normal using some realistic dimensions for a load applied at the very top end of the bridge. For a load at this point the board is in fact stiffer along the grain with the normal orientation than it would be if the orientation were switched by 90 degrees because the load is so close to the edge of the board. However, if you move down the scale a bit, in to the so called killer octave then the story is different. If the grain were oriented at 90 degrees to the 'normal' orientation you get considerably more stiffness along the grain than you do with the normal orientation. A couple of other points here: 1. I think Del made the point that by switching the grain orientation you might stiffen up the bass area where you don't want additional stiffness. However, it seems to me that softening up the bass end is easier than stiffening up the treble end. You can thin or float the board or play around with rib dimensions. So I don't see this as a reason not to change grain angle. 2. As you pointed out, from what Dale had pointed out earlier, normally the board is more or less crowned along the rib direction (what is now normally the board cross grain direction) and then the board is forced down along the grain (in its stiff direction which makes it harder to pull down) upon installation. Perhaps it would make more sense to crown along the grain and do the forcing down across the grain since the board is more flexible in that direction. Phil --- Phillip Ford Piano Service & Restoration 1777 Yosemite Ave - 215 San Francisco, CA 94124
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