<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>New board with cut-off for Steinway XR</title></head><body> <div>Hi all,</div> <div><br></div> <div>We're currently rebuilding an interesting little piano, a 1925 Steinway XR grand (this piano has a model M plate) with an American Black Walnut art case and an Ampico reproducer.</div> <div><br></div> <div>Our brief from the owner was that he wanted it rebuilt to original spec, ie. without any modification bells and whistles, since the piano was in original condition when he purchased it. The board wasn't too good from a visual and tonal perspective so we decided to replace it.</div> <div><br></div> <div>The first plan was to build a compression crowned panel to keep it totally original. However, with only ten ribs and no bass corner cut-off, I decided that the board might be better made as a hybrid with crowned ribs and a moderately dried panel to 6%. So our purest ideals didn't last for long. I made a test soundboard strip of the longest rib (1200 mm) and found that it was very weak on account of the long span, with a quite high crown of 14 mm in the middle of the rib. For the sample, the rib-top was machined with a 60' radius. The dried test panel was glued to the rib with the rib-top-surface held at the same 60' radius. After panel re-hydration the test strip crowned a further 5.5 mm. This level of crown is likely to cause all sorts of packing problems with the rear aliquot blocks. Furthermore, I just don't like the middle-order ribs being so long and weak. So on Thursday night I took one of my laminated cut-off pieces and laid it in the case, just to have a look at possibilities. It made so much sense, and I can't see the point of re-boarding a case with an original design board which may fail in a decade or so on account of poor design.</div> <div><br></div> <div>So I called the owner in for a discussion. After explaining my thinking, he agreed that since we could cover the bass corner with the soundboard panel, thus hiding the evidence, and since the player gear will fully block visual access to the underside of the board, we decided to press ahead and fit one of my laminated cut-offs to the case. I'm still going to make the board as a hybrid supported unit, to keep something of the original design philosophy of the original maker intact. With the cut-off, the two longest ribs which were 1200 mm long will now be around 850 long. This will be a much better result, since the middle-order ribs will be stiffer than those in the bass and the mid-board crown will now be much less on account of the shorter span, which will make the setup prior to stringing a lot simpler.</div> <div><br></div> <div>Here are some image links. I worked a bit over the weekend and got the cut-off fitted.</div> <div><br></div> <div>Here is an image of the cut-off with the rib notching machined before fitting it to the case.</div> <div><font face="Lucida Grande" size="-4" color="#000000">http://members.optusnet.com.au/ronovers/steain.bd6.jpg</font ></div> <div><br></div> <div>Here is the cut-of clamped in place with the ribs stock sitting in the notches for checking prior to gluing to cut-off in place.</div> <div><font face="Lucida Grande" size="-4" color="#000000">http://members.optusnet.com.au/ronovers/steain.bd7.jpg</font ></div> <div>As you can see, the cut-off greatly improves the structural layout and soundboard-area distribution.</div> <div><br></div> <div>Here is an image of the cutoff glued and clamped into place.</div> <div><font face="Lucida Grande" size="-4" color="#000000">http://members.optusnet.com.au/ronovers/steain.bd8.jpg</font ></div> <div>I was feeling a bit ho-hum about this piano with the original board concept, but now it will be very interesting to hear the end result.</div> <div><br></div> <div>Sorry I haven't contributed to any list discussion lately, since I've had a whole lot of other stuff to attend to.</div> <div><br></div> <div>Regards,</div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font><font color="#000000"><br> _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:ron@overspianos.com.au<br> _______________________</font></div> </body> </html>