<html> <head> <style> .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } </style> </head> <body class='hmmessage'><DIV>Hi Ric,   No problem. Some factories have presses with a slotted perimeter to position the ribs on the panel. They can do this because they are producing numerous boards with the same rib scale and layout.  The presses have a frame with pre-positioned arms that come down to the ribs as a unit and are inflated all at the same time. Our press consists of several individual units that are positioned one at a time. This allows us to enact changes in the rib layout from piano to piano without having to reconfigure a large fixed press. We have limited space in our shop, so another advantage to individual frames and cauls is the ability to store the presses in a small area when not being used. Also, our press frames have removable cauls which allows us to remove one caul and replace it with another of a different radius if desired. </DIV> <DIV>                Michael Spreeman <A href="http://www.spreemanpianoinnovations.com/" target=_blank>http://www.spreemanpianoinnovations.com</A></DIV> <HR id=EC_stopSpelling> > Date: Mon, 4 Aug 2008 09:22:16 +0100 > From: ricb@pianostemmer.no > To: pianotech@ptg.org; m_spreeman@hotmail.com > Subject: Crowning one rib at a time -- Spreeman > > Was reading about the Ravencroft instrument and have been curious about > many things since first hearing about it. On the website it says > somewhere that the soundboard is crowned "one rib at a time". I wonder > if you could be so kind as to expound on that a bit. Exactly how do you > crown a board one rib at a time ? > > Thanks if you can find the time to explain > Cheers > RicB <HR> Get Windows Live and get whatever you need, wherever you are. <A href="http://www.windowslive.com/default.html?ocid=TXT_TAGLM_WL_Home_082008" target=_blank>Start here.</A> <hr />Reveal your inner athlete and share it with friends on Windows Live. <a href='http://revealyourinnerathlete.windowslive.com?locale=en-us&ocid=TXT_TAGLM_WLYIA_whichathlete_us' target='_new'>Share now!</a></body> </html>