<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: Fw: Short Treble (sustain?)</title></head><body> <div><font face="Arial" size="-1">At 9:58 PM +0000 4/11/03, Michael Gamble wrote:</font></div> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Why not see what response your observations get from Grotrian-Steinweg themselves?</font></blockquote> <div><br></div> <div>The recapping job I mentioned was undertaken back in 1989. I have observed since then, many other instruments from the same manufacture with similarly inappropriate bridge pin spacing<font color="#0000FF"> (often with the resultant elongated or completely collapsed bridge pin holes)</font>. Furthermore, with regard to the piano repair in question, the intention originally was to recap the treble bridge only. After re-cutting the notching and re-drilling the bass bridge in preparation for the oversize bridge pins, we found that the front and rear pins (in the bichord section) were running into each other towards the bottom of the bridge pins holes. To explain further, while driving the back scale pins they were running into the speaking length pins somewhere below the bridge cap.</div> <div><br></div> <div>I was absolutely less than impressed at the time. Since we had to turn around and recap the bass bridge and re-position the back row of pins to cure the problem. If a factory, which lays claim to making a quality piano, can't even get the bridge pin field laid out so that the pins don't run into each other below the bridge cap, I can't see the point in contacting them to tell them about it. After all, most messengers usually get shot, and what would a small time piano re-builder down in the colonies know about the problem anyhow?</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">Do you mean Model 220? Or should it be Model 225?</font></blockquote> <div><br></div> <div>The Grotrian seven foot class of grand piano in the early '70's was a 220. A 223 was released sometime after 1975 (my first year working with pianos).</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1"> I have a superb 225 on my rounds and have been corresponding with Grotrian on the subject of a 10 year service/regulation.</font></blockquote> <div><br></div> <div>The 225 is a later piano again. Would you measure the bridge pin spacing, in the highest treble string section, between the outside unisons (centre to centre) next time you see it? I'd be interested to know if they are still building them the same way.</div> <div><br></div> <div>Ron O.</div> <div><br></div> <blockquote type="cite" cite><font face="Arial" size="-1">They have been most helpful. Write to: Burkhard Kaemmerling at:</font> <a href="mailto:kaemmerling@grotrian.de"><font face="Arial" size="-1">kaemmerling@grotrian.de</font></a></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Regards</font></blockquote> <blockquote type="cite" cite><font face="Arial" size="-1">Michael G (UK)</font></blockquote> <blockquote type="cite" cite>----- Original Message -----</blockquote> <blockquote type="cite" cite><b>From:</b> <a href="mailto:sec@overspianos.com.au">Overs Pianos</a></blockquote> <blockquote type="cite" cite><b>To:</b> <a href="mailto:pianotech@ptg.org">Pianotech</a></blockquote> <blockquote type="cite" cite><b>Cc:</b> <a href="mailto:alfailsa@accsoft.com.au">Alf Reichardt</a></blockquote> <blockquote type="cite" cite><b>Sent:</b> Monday, November 03, 2003 10:21 PM</blockquote> <blockquote type="cite" cite><b>Subject:</b> Re: Short Treble (sustain?)</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>Del, Ron N. and all,</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>The string buzzing on the side of the agraffe slot is most certainly the problem. Earlier in my career I recapped the failed bridges on a Grotrian 220. Since the owner was travelling to Germany on business, when he visited the factory they sold him a replacement treble bridge cap. Unfortunately, the new bridge cap was afflicted with the same 'disease' which was common to '70s era Grotrians<font color="#0000FF"> (I have no idea if it remains a problem with their contemporary instruments)</font>. However, the bridge pin spacing was so close that there was virtually no free space between the string and the adjacent bridge pin. Consequently, there remain several notes on my client's Grotrian 220 which have string noise at the bridge pins<font color="#0000FF"> (which varies in intensity according to the relative humidity at the time)</font>. A gentle side pressure on an offending bridge pin will stop the noise.</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>These Grotrian bridges from the '70s are prone to failure on account of the close bridge pin spacing. There is simply insufficient bridge wood around the pins to provide adequate support for the side thrust on the pins. On Grotrians from earlier periods they have used a wider bridge pin spacing and they do not have the same problem. Isn't it amazing how corporate knowledge often fails to be passed down from one generation to another? The 'Johnny come latelys' turn up with new thinking but fail give appropriate consideration to lessons learned long ago by an older generation of thinkers. I'm all for innovative technologies, but one should come to it after stepping off from the knowledge which has gone before.</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>Clearly, the idea of placing a damping material on a noisy string segment<font color="#0000FF"> (wether it be new-age silicon as in the case of the Stuart agraffe, a piece of felt or a lump of fat from under the barbecue)</font>, its still is just a case of fixing the symptom instead of addressing the cause of the disease.</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>The bridge agraffe we have been discussing is a case in point. It simply wasn't thought through prior to execution. I concur with your views Ron N. and Del, with regard to widening the slots and using rolled pins as a solution. Less overall height would be a plus as well. As you and I have both mentioned previously Ron N., it would allow for the retention of a more sensible bridge height and stiffness.</blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>Ron O.</blockquote> <blockquote type="cite" cite><br> <blockquote type="cite" cite>----- Original Message -----<br> From: "Ron Nossaman" <RNossaman@cox.net><br> To: "Pianotech" <pianotech@ptg.org><br> Sent: November 01, 2003 8:23 PM<br> </blockquote> <blockquote type="cite" cite>Subject: Re: Short Treble (sustain?)<br> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>I suspect the problem is with the string buzzing against the side of the<br> </blockquote> <blockquote type="cite" cite>slot.<br> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>Del<br> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite> Perhaps, though I have a hard time imagining much vibration excursion in<br> </blockquote> <blockquote type="cite" cite> that short segment. At that, how difficult or more expensive is a wider<br> </blockquote> <blockquote type="cite" cite> slot, as long as you're cutting one anyway? It's not like it will cost<br> </blockquote> <blockquote type="cite" cite> anything important in rigidity. A grooved center rod would help too,<br> </blockquote> <blockquote type="cite" cite>though<br> </blockquote> <blockquote type="cite" cite> it would cost a bit more to produce.<br> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite> Ron N<br> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite>-------------<br> <br> As do I. I did think it a possibility, though, as I worked with similar<br> devices at Baldwin. The easiest way to solve the problem (if it exists)<br> (and, other than putting some damping material between the leading<br> termination and the center deflector rod) is, as you suggest, to groove the<br> center rod. This could be rolled and, in quantity, is not as expensive as<br> you might think. In limited quantities, however, it might well be a factor.<br> This can be used to solve another problem as well -- the varying string<br> deflection angles as the wire size changes. I played around with several<br> groove depths, deeper in the low tenor and bass, more shallow in the<br> tenor/treble.<br> </blockquote> <blockquote type="cite" cite>Del<br> </blockquote> </blockquote> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite><tt>--</tt></blockquote> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></blockquote> <blockquote type="cite" cite><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font><font color="#000000"><br> _______________________</font></blockquote> <blockquote type="cite" cite><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></blockquote> <blockquote type="cite" cite><font color="#000000">mailto:info@overspianos.com.au<br> _______________________</font></blockquote> <div><br></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:info@overspianos.com.au<br> _______________________</font></div> </body> </html>