<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html xmlns:v="urn:schemas-microsoft-com:vml" = xmlns:o="urn:schemas-microsoft-com:office:office" = xmlns:w="urn:schemas-microsoft-com:office:word" = xmlns="http://www.w3.org/TR/REC-html40"> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; = charset=iso-8859-1"> <meta name=ProgId content=Word.Document> <meta name=Generator content="Microsoft Word 10"> <meta name=Originator content="Microsoft Word 10"> <link rel=File-List href="cid:filelist.xml@01C53ECE.7D023950">  <style>  </style>  </head> <body lang=EN-US link=blue vlink=purple = style='tab-interval:.5in' id="role_body" bottomMargin=7 leftmargin=7 topmargin=7 rightMargin=7> <div class=Section1> Why would this = be better than simply creating a rib crowned and supported panel that can be = compressed to the requisite stiffness through the use of downbearing without overstressing the panel?<o:p></o:p> <o:p> </o:p> <div> David Love davidlovepianos@comcast.net <o:p></o:p> </div> -----Original = Message----- From: = pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Erwinspiano@aol.com Sent: Monday, April 11, = 2005 6:34 PM To: pianotech@ptg.org Subject: Re: Virtual = Ribs, A new crown support method <o:p> </o:p> <div> <div>   RIc<o:p></o:p> </div> <div>   May the force? be with you brother.grin<o:p></o:p> </div> <div>   Dale<o:p></o:p> </div> <blockquote style='border:none;border-left:solid blue = 1.5pt;padding:0in 0in 0in 4.0pt; margin-left:3.75pt;margin-top:5.0pt;margin-bottom:5.0pt'> Hi folks After a few months of experimenting, I am ready to announce a new (I = believe)  method of supporting crown for any type of soundboard. = The method allows for both restoring crown and supporting it in older panels, and designing new panels in which the concerns of mass levels = and degree of assembly stiffness can be to a far greater degree treated = independantly. In essence, an array of repelling high power neodym magnets of appropriate dimmensions and strengths are used to support crown against = downbearing from the strings. One set are imbeded in soundboard button = similar wooden sheaths and are attached to the soundboard with glue and = screws.  Opposing these is another set which are mounted into a = very strong wooden beam such that their distance from the soundboard attached = magnets can be adjusted easily from below.  One can either choose = to simply provide support directly under the bridge, or without too much = difficulty, contrive what amounts to a system of virtual ribs with fully = adjustable support for crown. For edification... Neodym magnets that measure 30 mm Ų by 5 mm thick = can hold / push approximately 25 kilos.  Since there is no phsyical = connection between the soundboard and opposing magnets, the assembly is = not directly mass loaded. Hence stiffness and crown support is provided = without mass loading. More later on as I formalize an article on a working example I am hoping = to finish soon. As is my habit... this is an open source idea, I encourage any and all = to take up and refine it in their own fashion.  My own initial = results indicate that the principle is very successful. Cheers Richard Brekne<o:p></o:p> </blockquote> </div> <div>  <o:p></o:p= > </div> </div> </body> </html>