<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <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:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40" xmlns:ns0="http://schemas.microsoft.com/office/2004/12/omml"> <head> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="Street"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PostalCode"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="State"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="address"/> <o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"/>  <style>  </style>  </head> <body bgcolor=white lang=EN-US link=blue vlink=purple> <div class=Section1> I appreciate the detailed explanation.<o:p></o:p> I am not seeing rib support for the bass bridge?? That is, not the kind of support that I would typically design into a grand rib pattern.<o:p></o:p> Gene<o:p></o:p> <o:p> </o:p> <o:p> </o:p> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Delwin D Fandrich Sent: Friday, May 18, 2012 10:46 AM To: <st1:PersonName w:st="on">pianotech@ptg.org</st1:PersonName> Subject: Re: [pianotech] S&S K(52) Restoration<o:p></o:p> </div> <o:p> </o:p> Yes. The Z-Bar extends from just below the end of the treble bridge—where it is physically attached to the back structure—to a point just opposite the tenor end of the bass bridge. From just under the tenor bridge the Z-Bar is glued to the soundboard panel but not the back structure. The ribs are centered on the bridge and extend up to the Z-Bar. There are no functional ribs below and to the right of the Z-Bar although we did end up putting several thin, acoustically non-functional ribs over there to keep the solid wood soundboard panel from buckling and cracking. <o:p></o:p> <img width=290 height=249 id="Picture_x005f_x0020_1" src="cid:image001.jpg@01CD34EB.1765D140" alt="Description: C:\Documents and Settings\Delwin D Fandrich\My Documents\FileCabinet -- DDF\Piano Designs\Fandrich--122 Vertical\U22-Master Drawings\U22 - Iron Plate Master jpg.JPG"><o:p></o:p> <o:p> </o:p> The Z-Bar is essentially a soundboard sizing and shaping device and an impedance control device. It keeps the soundboard area small in the treble area where the frequencies are high and the system mobility needs to be restricted, allowing it to become gradually larger further down where the frequencies are lower and the soundboard needs more surface area and more mobility. Think of it as a mechanical crossover network.<o:p></o:p> <o:p> </o:p> The lower portion of the soundboard “floats” free of the back structure giving the low end of the bass bridge the controlled mobility needed to develop sound energy in the fundamental and lower harmonics.<o:p></o:p> <o:p> </o:p> In several demonstrations before groups of piano tuners and technicians the audience members were unable to say precisely where the bass/tenor transition took place. In one demonstration before a group comprised mostly of piano teachers and piano tuners and technicians the piano was compared note by note starting at C-88 and working down with a Bösendorfer Imperial grand; the consensus of the audience was that the little 122 cm tall vertical produced more power, along with better clarity and dynamic range down to about the last two octaves in the bass. <o:p></o:p> <o:p> </o:p> ddf<o:p></o:p> <o:p> </o:p> <div> Delwin D Fandrich<o:p></o:p> Piano Design & Fabrication<o:p></o:p> <st1:address w:st="on"><st1:Street w:st="on">6939 Foothill Court SW</st1:Street>, <st1:City w:st="on">Olympia</st1:City>, <st1:State w:st="on">Washington</st1:State> <st1:PostalCode w:st="on">98512</st1:PostalCode> <st1:country-region w:st="on">USA</st1:country-region></st1:address><o:p></o:p> Phone  360.515.0119 — Cell  360.388.6525<o:p></o:p> <a href="mailto:del@fandrichpiano.com">del@fandrichpiano.com </a>— <a href="mailto:ddfandrich@gmail.com">ddfandrich@gmail.com</a><o:p></o:p> </div> <o:p> </o:p> <div> <div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'> From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org] On Behalf Of Gene Nelson Sent: Friday, May 18, 2012 7:26 AM To: <st1:PersonName w:st="on">pianotech@ptg.org</st1:PersonName> Subject: Re: [pianotech] S&S K(52) Restoration<o:p></o:p> </div> </div> <o:p> </o:p> <div> Ribs fanned and perpendicular to long bridge?<o:p></o:p> </div> <div> Does Z structure define rib length in that area?<o:p></o:p> </div> <div> Gene <o:p></o:p> </div> </div> </body> </html>