<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body bgcolor="#ffffff" text="#000000"> Hi Ron,,,, I'm going to defer to Arnold on this one, as he is better informed and knows Udo much better then I do. One meeting at a convention is hardly enough to qualify as <<establishing a relationship>>. Otherwise thanks again for a very interesting post making clear again  many of the points youve brought up before.  A few answers to direct questions you ask me.... 1.  The K point being the most vunerable point. To begin with it seems clear now that I have not understood this "K point" thing clearly, something I've suspected all along which is why I've posted about it from time to time... hopeing to flush out some more info about it.  Arnold seems to at least have heard the term, and has corrected me (as you do also here) as to the location of the highest point on the panel.  What I can do is contact the fellow I had my origional discussion about this so called K-point and see if I can get a better picture of what he meant then.  Perhaps that will put my conversation with Udo into better perspectives. With this said, then I understood that the highest point was the weakest, as it then was that point which would experience the greatest stress downwards by the application of string bearing. Since the basic understanding of this seems to be somewhat in error, I suppose this point would be erroneous as well, tho it does stand to reason that the highest point (in itself) would experience the brunt of the push downwards... yes ??? ... no ???  Your comments would be appreciated as always. 2.  I have no reason to doubt the claims that CC panels can be found often enough with reverse crown.  Tho I must admit I am somewhat miffed even now as to just how that condition comes about. Ribs that << resist crown >> should equally resist reverse crown to begin with, especially in the light of the fact that the nearer a panel is being compressed flat, the less increased downward pressure the strings are able to bring to bear.  Given some of the string deflection angles tossed around... it would seem that in some instances the strings would be getting  close to  holding the panel up before it gets completely flattened to begin with.  Correct my figureing here.. but a... say 30 cm long string with a 1 degree deflection angle has the potential to move about 5mm downwards before it is straight.  That in itself is enough to provide for reverse crown I suppose.......say even as much as 2 mm... but then how much pressure does it take to resist that ??  This equivilates to .38 degrees of string deflection given that same string and the need to deflect a string plane 2 mm.  For the SB assembly to experience this reverse crown the top flange of the ribs would have to come into a state of compression from being in a state of tension, and the bottom of the panel would have to have moved from compression towards a tensive state.  Given the assumption that this reverse crown can only come about because the panel itself has suffered so much compression damage as to loose its ability to stress the system enough to resist down bearing,  one has to wonder how it can then be tensioned at all, and how the ribs which have great strength against any stress along their grain can not suffice to hold the downward pressure of the strings in check. Afterall... the panel itself can no longer be placing any stress on the system as such because its assumed that its ability to do so is already destroyed. 3: (copied from below) <blockquote> <pre>>Udo was of the position that along the grain >crowning was every bit as important as cross >grain crown. I would have expected this point to be a 'position', rather than a 'conclusion'. </pre> </blockquote> I rather thought I did refer to it as a 'position' . I did not use the word 'conclusion' at all... yes ???  And, as I understood him to say, he meant that the compression along the grain helped to stablize the situation cross grain.  Now whether this is true or not I do not know. But it certainly does not become true or false  simply because some one claims it to be so. If there is some clear documentation to show one way or the other, I am sure we all would love to  see it.  I hadnt really thought the question had been asked much as I've only run into this kind of thing over here.  As to your position relative to how much is needed  <blockquote> <pre>"to achieve an alleged worthwhile crown along the grain."</pre> </blockquote> again.. there seems to be an apparent dissagreement between your position and that of Steingræber. Tho perhaps this is just because of some misunderstanding on my part.. I can not say.  Thats why I ask ... yes ?? I agree that Ron N's comments relative to the bridge rolling were very well put. As to the final comments relative to the claim of a different acoustical result given the two methods.  Given the significant differences in the stresses the ribs and panels are subjected too, I really have difficulty understanding how and why one should not expect a different result.  I just wrote a post which went more into why, so I wont repeat it here.  But as to the importance of along the grain crown and compression to the end acoustical result... I cant say, and it seems you havent got more then belief on the matter either.  All I can do is report what my understanding of Steingræbers position is.  Arnold no doubt has a better understanding of all this, so if he chirps in then so much the better. Thanks for some great reading Ron. Cheers RicB </body> </html>