Thanks very much for sharing, Louis! These are exactly the kinds of ideas I was hoping to get. :) Bill Sent from my BlackBerry smartphone from Virgin Media
-----Original Message----- From: "Louis Aull" <aul...@comcast.net> Sender: lute-...@cs.dartmouth.edu Date: Fri, 18 May 2012 15:43:22 To: <lute-buil...@cs.dartmouth.edu> Subject: [LUTE-BUILDER] Re: Scalloped Ribs ------=_NextPart_001_000B_01CD350C.F4FEEE80 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Bill, A lute rib tapers at each end, which means the outer fibers that would have made it down to the fastening point on each end are cut. As a result, there is no circular binding force to hold them down like the center fibers of the rib have. As the wood naturally tries to straighten out of its bend, the scallop occurs since there is nothing to stop the outer fibers from straightening. To enhance this naturally, don't bend the rib completely to the form, and use some force to pull the rib onto the form to complete the curve. The edges will curl up away from the form more. To defeat this, over bend and heat twice so the rib is over curved, and the scallop will lay flat when forced onto the form. Cut the rib roughly to shape before bending . Another trick is to fasten the rib at each end on the form and use a heat gun on the outer edges of the rib. The heat will cause the bent curve on the outer portions to relax and the rib will curl up more. All these methods produce a mild scallop. It helps to bend all the ribs before installing them so they are consistent and will meet up on the form. For a brutal scallop, you would need a shaped forming iron to force the complex curve (yuk). The thinner the rib, the more the scallop. However, get too thin and you risk plastic deformation of the shell at the neck block, and the neck will come forward, ruining the action. I use aircraft silk on the back of rib joints and have never had one crack. I can actually heat the inside of the shell before putting on the soundboard to relax out any stress in the shell. This also enhances the scallop. I have seen lutes (60's and 70's) where the maker made the ribs thick and scraped the scallop out. Louis Aull Phone: 770.978.1872 Fax: 866.496.4294 Cell:404.932.1614 LOGO3 ------=_NextPart_001_000B_01CD350C.F4FEEE80 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable <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:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 12 (filtered medium)"> <!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} </style> <![endif]--> <style> <!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} @font-face {font-family:Tahoma; panose-1:2 11 6 4 3 5 4 4 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; margin-bottom:.0001pt; font-size:11.0pt; font-family:"Calibri","sans-serif";} a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {mso-style-priority:99; color:purple; text-decoration:underline;} p.MsoAcetate, li.MsoAcetate, div.MsoAcetate {mso-style-priority:99; mso-style-link:"Balloon Text Char"; margin:0in; margin-bottom:.0001pt; font-size:8.0pt; font-family:"Tahoma","sans-serif";} span.EmailStyle17 {mso-style-type:personal-compose; font-family:"Calibri","sans-serif"; color:windowtext;} span.BalloonTextChar {mso-style-name:"Balloon Text Char"; mso-style-priority:99; mso-style-link:"Balloon Text"; font-family:"Tahoma","sans-serif";} .MsoChpDefault {mso-style-type:export-only;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in;} div.Section1 {page:Section1;} --> </style> <!--[if gte mso 9]><xml> <o:shapedefaults v:ext="edit" spidmax="2050" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext="edit"> <o:idmap v:ext="edit" data="1" /> </o:shapelayout></xml><![endif]--> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> <p class=MsoNormal>Bill,<o:p></o:p></p> <p class=MsoNormal><o:p> </o:p></p> <p class=MsoNormal>A lute rib tapers at each end, which means the outer fibers that would have made it down to the fastening point on each end are cut. As a result, there is no circular binding force to hold them down like the center fibers of the rib have. As the wood naturally tries to straighten out of its bend, the scallop occurs since there is nothing to stop the outer fibers from straightening. To enhance this naturally, don’t bend the rib completely to the form, and use some force to pull the rib onto the form to complete the curve. The edges will curl up away from the form more. To defeat this, over bend and heat twice so the rib is over curved, and the scallop will lay flat when forced onto the form. Cut the rib roughly to shape before bending . Another trick is to fasten the rib at each end on the form and use a heat gun on the outer edges of the rib. The heat will cause the bent curve on the outer portions to relax and the rib will curl up more. All these methods produce a mild scallop. It helps to bend all the ribs before installing them so they are consistent and will meet up on the form. For a brutal scallop, you would need a shaped forming iron to force the complex curve (yuk). The thinner the rib, the more the scallop. However, get too thin and you risk plastic deformation of the shell at the neck block, and the neck will come forward, ruining the action.<o:p></o:p></p> <p class=MsoNormal><o:p> </o:p></p> <p class=MsoNormal>I use aircraft silk on the back of rib joints and have never had one crack. I can actually heat the inside of the shell before putting on the soundboard to relax out any stress in the shell. This also enhances the scallop.<o:p></o:p></p> <p class=MsoNormal><o:p> </o:p></p> <p class=MsoNormal>I have seen lutes (60’s and 70’s) where the maker made the ribs thick and scraped the scallop out.<o:p></o:p></p> <p class=MsoNormal><o:p> </o:p></p> <p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Louis Aull<o:p></o:p></span></p> <p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Phone: 770.978.1872</span><o:p></o:p></p> <p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Fax: 866.496.4294<o:p></o:p></span></p> <p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Cell:404.932.1614 </span><o:p></o:p></p> <p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><img width=75 height=65 id="Picture_x0020_1" src="cid:image001.gif@01CD3508.EBB3EBE0" alt=LOGO3><o:p></o:p></span></p> <p class=MsoNormal><o:p> </o:p></p> </div> </body> </html> ------=_NextPart_001_000B_01CD350C.F4FEEE80-- -- To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html