Soundboard Evaluation

[Ron Nossaman]

>Well, let's push the board up 1mm. At note E4, the back scale would go from 
>a  -2/3° angle to a +2/3° angle, and the front angle would go from a +1/6° 
>angle to about +1/4° (I'm just guessing at a 2-inch back scale and a 20-inch 
>front scale). I hope I have done my math correctly (I actually had quite a 
>bit of advanced math in college, but, well, er, a, some of it has slipped on 
>by). 
>That seems like a lot of change for a tiny bit of soundboard movement. 
>But I do see your point. It doesn't have to roll to produce negative back 
>bearing with positive front bearing. Interesting. Thanks.
>
>Terry Farrell

That looks pretty close. And yes, the stuff does evaporate out of old brain
cells. All of them, near as I can tell, but then how could I tell? It does
seem like a lot of angular change for a small vertical movement, but how
far does a 72' (22M) radius crowned rib of 508mm (20") have to be pushed
down to be flat on top?


Ron N