<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re:seeking clarity, was relevance of bridge pin spacing</title></head><body> <div>Gene and all,</div> <div><br></div> <blockquote type="cite" cite>. . . In my case both front and rear pin positions would be shifted from their position on the original bridge.</blockquote> <div><br></div> <div>Correct - the front rows are adjusted for scale correction, while the rear rows are adjusted to achieve an optimal layout while ensuring front/rear-row pin clearance within the bridge body. As Ron N mentioned in a previous post, its better to make the spacing wider/longer in the low bass, particularly in long pianos where the angle between the strings and bridge line converge more. It reduces the length of the bridge notching, and there's no down side.</div> <div><br></div> <blockquote type="cite" cite>  Maybe in Frank and Ron's case the hitch pins have not been positioned yet? Am I missing something?</blockquote> <div><br></div> <div>The re-scaled layout is derived using a rubbing from the original bridge as a starter guide. String spacing errors are corrected at the same time as the new speaking lengths are marked out on the rubbing. A thin veneer strip is placed between the rubbing and the original bridge. After the new scale and spacings have been finalised, the new bridge-pin hole positions are punched through to the veneer strip below, which is used as a template for drilling the new bridge cap, and is retained for all future rebuilds of this iteration of the model. Here's a link below to an image taken from our recent re-scaling of a newish Hamburg D (2000 manufacture).</div> <div><br></div> <div>http://members.optuszoo.com.au/kristieovers/chrstch7.jpg</div> <div><br></div> <div>The new lines for the front and rear pin rows can be seen against the original rubbing. Notice that the speaking length of the note directly under Wal's right hand is being shortened by approx 1 cm. I left the original C88 at 49.5 mm, and lengthened F21 out from its original 1823.5 mm to 1860 mm (on the older Ds, F 21 was nominally 1830 mm). We found that there were quite dramatic speaking length adjustments required from around the middle of the temperament area down, which explains why the chromatic thirds between G35/B39 and G#36/C40 are always problematic when laying a temperament in the D. The re-scaled bridges make the job of laying a smooth temperament very much easier. Surprisingly, the new version of the D scale is no better than the first version we re-scaled on a circa 1962 piano, back in 1992.</div> <div><br></div> <div>Re-scaling these pianos with a transition bridge is a much better rework (as Ron N has done), but in this case the piano is only seven years old, so I decided to keep the original bridge root and soundboard as an economy measure.</div> <div><br></div> <div>Below are some image links, taken from a recent rebuild of a 1992 Steinway D.</div> <div><br></div> <div><font face="Lucida Grande" size="-4" color="#000000" >http://members.optuszoo.com.au/kristieovers/st.mary's1.jpg</font></div > <div>An overview of the piano</div> <div><br></div> <div><font face="Lucida Grande" size="-4" color="#000000" >http://members.optuszoo.com.au/kristieovers/st.mary's2.jpg</font></div > <div>Close view of the front duplex bars. In this case the client wanted to retain the original bars, so the originals were reshaped and hardened.</div> <div><br></div> <div><font face="Lucida Grande" size="-4" color="#000000" >http://members.optuszoo.com.au/kristieovers/st.mary's3.jpg</font></div > <div>View of the base section, showing the EN plated agraffes. The base is revised, but with the same speaking lengths.</div> <div><br></div> <div><font face="Lucida Grande" size="-4" color="#000000" >http://members.optuszoo.com.au/kristieovers/st.mary's4.jpg</font></div > <div>Close view of the new multi-laminated bridge cap. This cap has seven layers of 0.5 mm rock maple. The rear aliquot blocks are packed slightly higher to fine tune the downbearing in this instance.</div> <div><br></div> <div>Ron O.</div> <div><br></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>