[pianotech] FW: laminated ribs again

[Ron Nossaman]

> Hi,
> Dont know so Ima goina ask.
> Is there a crown ridge that sort of follows the bridge line?

In a rib that's a constant radius circle segment, the high 
point is ALWAYS in the center of the ribs. That's geometry, no 
matter what sort of "logic" and body english is employed to 
try to make it not so. If the bridge is centered on the rib 
then yes, the bridge is on the high point. If not, no. With 
non constant radius crowning (parabola, sine, catenary, or 
multiple radii), you can put the high point anywhere you like.


> Could one cut kerfs in the ribs radiating away from the bridge line 
> and glue in wood shims
> to induce more crown? 

Sure, if you really want negative crown, unless you kerf and 
wedge from the panel side. More geometry.

Ron N