Big, fat, wide, shallow rib mystery "solved" ???????

[Ron Nossaman]

> Dear Everyone,
>     Today I spoke with one of the most utterly
> respected bellymen, frequently published in the
> Journal and in a "position" to know PLENTY about old,
> pre - AMPICO Knabes...... 
>      Well, HE said, after examining these wide, fat,
> shallow ribs upon removal from old boards, that they
> ARE "rib-crowned"! 
>      And so, perhaps, also with my Ivers and Pond, and
> Packard ???
>     So much for the notion that these ribs are, by
> necessity, flat...... 
> 
>      Peace,
>      G

I replaced the board in an old Knabe grand a few years back. 
The top four treble ribs were not only crowned (about 4 meter 
radius, at that), but laminated. I couldn't tell whether any 
of the other ribs were crowned, but the board was concave 
under bearing load.

There's a difference between rib crowned and rib supported. 
These boards are still primarily panel supported, crowned ribs 
or not.


> P.S. I'm now wondering if the grain orientation on
> these ribs is such as to better lend themselves to
> elasticty. 
>      Just a "hunch".

Do some deflection testing and find out instead of sitting 
there "hunching".

Ron N