Crowning methods, was soundboards.

[Terry]

I believe it would be accurate to say that there is a continuum between the
two extremes of 100% compression crowning and 100% rib crowning - it is not
as if there are two distinct schools of thought on the subject.

Some lower-end small pianos have been manufactured with super-dry panels,
flat ribs, with the ribs glued to the panel on a flat surface - that process
represents one end of the spectrum (actually, I think many, many, if not
most, vertical pianos have soundboards manufactured like that). The other
end of the spectrum would be no panel drying at all, and ribs cut/formed to
the desired radius. I am not aware of anyone that is at that end of the
spectrum. All the soundboard builders that I am aware of  who build "rib
crowned" soundboard utilize at least some small degree of panel drying prior
to gluing ribs to the panel.

I believe most soundboard manufacturers build hybrid soundboards - that is
the ribs will have some radius cut/formed into them (often the 60-foot
radius one hears of so often) and the panel will receive a fair bit of
drying prior to ribbing. Steinway even modifies the 100% compression
crowning process by drying the panel, using flat ribs, but gluing them to
the panel in radiused cauls. Most builders that utilize some pre-formed
radii to their ribs will glue clamp the ribs to the panel using a matching
radii caul.

I think if you looked at all the soundboard builders in the world, you will
see that continuum in the building process from one extreme to the other (or
nearly so).

Terry Farrell



> Hi Clyde,
>
> Yes, Young Chang uses rib crowning.
>
> At 07:21 PM 20/01/2005 -0800, you wrote:
> >Thanks RicB,  are there any manufacturers presently employing rib
crowning?
> >  Thanks, Clyde Allen