<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Bridge design</title></head><body> <blockquote type="cite" cite>Del wrote:<br> > This theory also explains why<br> > so many builders were reluctant to put a dog-leg into the bridge at<br> > plate/scale breaks to maintain good scaling. They were not just being cheap<br> > or negligent.<br> <br> Ahhhhhhhh. I have a 5' 10" 1900 Bechstein awaiting rebuilding and the long bridge has absolutely NO HINT of a dogleg at any of the breaks. The curve is perfectly consistent. I had noticed that a long time ago and felt surprised that a manufacturer like Bechstein would be so cheap as to not go the distance of putting on a proper dogleg. Now I know that being cheap is not likely the answer. Thanks.<br> </blockquote> <blockquote type="cite" cite>Terry Farrell</blockquote> <div><br></div> <div>That just depends what their design priorities were since, when there's no dog leg, the tension percentage adjacent to the plate struts will be a complete disaster<font color="#0000FF"> (I have the 6' scale in my collection so I know this to be the case)</font>. The top break can be laid out with good scaling and virtually no dog-leg by using the width of the bridge top, running the bridge pin field to the back on treble side of the strut and vice versa on the bass side. But the second break down will definitely be a scaling problem unless a dog-leg is incorporated. Although this will involve quite a deal of extra work when shaping up a bridge, it definitely does yield tuning stability benefits if the scale is not compromised across the struts.</div> <div><br></div> <div>The Bechstein 6' and 5'10" scales are further examples of instruments which were designed with the last note on the long bridge at note B27 - a very poor choice (113 cm speaking length on the 6' piano) for a piano of this length. I just can't understand why such instruments are still being built with such ordinary scale designs. Its just a waste of metal, wood and felt.</div> <div><br></div> <div>I just took delivery of a brand new Samick SPG-158 for repair<font color="#0000FF"> (thanks to a careless forklift driver)</font>. This piano, with its new wide-bodied back, was being heralded as a new and more advanced design from Samick. What a frustrating instrument! It would appear that the designer just didn't have the first clue when it comes to scaling the first instance, and bridge placement on the board in the second. Furthermore, the bass bridge is suspended for its entire length, and the low end of the treble bridge has been placed so far out on the body of the board that it sounds like a duck just before it crosses over to the bass bridge. The back scale on the low bass is too short (45 mm) with a wider than necessary hitch riser (35 mm). This, in combination with an English eye which takes up 23 mm of the 45 mm back scale is guaranteed to ensure that the low bass virtually doesn't exist. The front duplexes are, as usual, too long and the counter bearing angle in the mid section is excessive. The scale has a hockey stick low end on the treble bridge with bichords for the last four notes on the same bridge. While the sound board panel is of solid spruce, already there is considerable compression adjacent to the sound board panel joints, and the maple bridges are not quarter cut. Wow, what a giant leap 'forward' to 1920.</div> <div><br></div> <div>I very much suspect the designer's brief might have been, above all else, to design a new piano with a wide body<font color="#0000FF"> (there seems to be an obsession with wide bodied designs ever since the Bostons turned up - but they all seem to suffer from poor bridge placement from what I've seen)</font>. What on earth is the utility of a wide body design, if the many other critical design issues that should be addressed in a modern design were not understood? While the general level of finish was a distinct improvement<font color="#0000FF"> (apart from the fact that damper wire guides were drilled out of position and the wires are buzzing on the strings)</font>, it not much use if the piano doesn't produce a satisfactory tone?</div> <div><br></div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times" color="#000000"><br></font></div> <div><font face="Times" color="#000000">       OVERS PIANOS</font></div> <div><font face="Times" color="#000000">Grand piano manufacturers</font></div> <div><font color="#000000">________________________</font><br> <font color="#000000"></font></div> <div><font face="Times" color="#000000">Web:   http://www.overspianos.com.au</font></div> <div><font face="Times" color="#000000">Email: mailto:ron@overspianos.com.au</font><font color="#000000"><br> ________________________</font></div> </body> </html>