R,C&S question JD

[Richard Brekne]

I dont see the relevance to the question about how much compression gets 
imparted into the panel when a given RC&S board gets subjected to enough 
downbearing to reduce its crown to 25 % (or any given amount for that 
matter) of its original height....which is the subject matter of the 
last few posts on this thread.

Cheers
RicB


    Percent residual crown doesn’t tell you much in a system that has
    variable
    radius control. If you start with a rib that has 10 mm of crown and
    deflect
    it 5 mm it has 50% left. If you start with a rib with 5 mm of crown and
    deflect it 5 mm it has 0%. But they both have the same amount of
    deflection
    for the given load. Targeted amounts of crown in pure CC boards are
    different because you are more limited to the amount of crowning you
    can get
    by virtue of panel compression. Like Ron, I would be interested to know
    from those of you do pure CC assemblies what your stated goals are
    in terms
    of crown and what you can realistically hope to achieve along
    specified rib
    lengths. My own view is that it is this unpredictability (among other
    things) that is a large part of the problem with pure CC boards.

    David Love
    davidlovepianos at comcast.net
    www.davidlovepianos.com