<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: Fw: Short Treble (sustain?)</TITLE> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 6.00.2800.1264" name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2></FONT> </DIV> <DIV style="FONT: 10pt arial">----- Original Message ----- <DIV style="BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A title=sec@overspianos.com.au = href="mailto:sec@overspianos.com.au">Overs Pianos</A> </DIV> <DIV><B>To:</B> <A title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV><B>Sent:</B> Wednesday, November 05, 2003 1:52 PM</DIV> <DIV><B>Subject:</B> Re: Fw: Short Treble (sustain?)</DIV></DIV> <DIV><BR></DIV> <DIV><FONT face=Arial size=-1>At 9:58 PM +0000 4/11/03, Michael = Gamble wrote:</FONT></DIV> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><FONT face=Arial size=-1>Why not = see what response your observations get from Grotrian-Steinweg themselves?</FONT></BLOCKQUOTE> <DIV><FONT face=Arial size=2>        = Ron Overs replied:</FONT></DIV> <DIV><FONT face=Arial size=2></FONT><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 cite="" type="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 cite="" type="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> <HR> </DIV> <DIV>Hello Ron O. Yes. I will take my 1/64" depth rule (which I usually = use for measuring string heights in Grands) and measure the top break bridge pin = spacing. I next see this piano on Friday 28th. November to prepare it = for a recital by Leon MacAulay.</DIV> <DIV>Interestingly I just did its first 10yr. action = regulation on it a couple of weeks ago and found the key dip was down to = 9mm and the hammer-rise almost non-existent. When new, the hammer-rise was fast = and furious!!! so I strengthened all the double-winged jack springs, put = 0.3mm paper punchings under every balance rail pin washer, then adjusted the set-off = and let-offs. There had been complaints from Susan Tomes (in particular) of = the "non-responsiveness" of this 225. We shall see. It has no spring assists = as the playing weight was specified to be 50gms.</DIV> <DIV>I am horrified to hear of your findings in that G-S 220 where the = speaking bridge pins are touching the duplex bridge pins "subcutaneously"! I = shall have to measure the bridge-width (distance between the front-back = pins) as well I think, and mic. up the bridge pins if I can get at them with the = micrometer. Then you can tell us your opinion on this newer beastie. :-)<BR></DIV> <BLOCKQUOTE cite="" type="cite"><FONT face=Arial size=-1>Regards</FONT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><FONT face=Arial size=-1>Michael = G (UK)</FONT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">----- Original Message = -----</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><B>From:</B> <A href="mailto:sec@overspianos.com.au">Overs Pianos</A></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><B>To:</B> <A href="mailto:pianotech@ptg.org">Pianotech</A></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><B>Cc:</B> <A href="mailto:alfailsa@accsoft.com.au">Alf Reichardt</A></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><B>Sent:</B> Monday, November 03, = 2003 10:21 PM</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><B>Subject:</B> Re: Short Treble (sustain?)</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Del, Ron N. and all,</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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 cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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 cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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 cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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 cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Ron O.</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR> <BLOCKQUOTE cite="" type="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 cite="" type="cite">Subject: Re: Short Treble (sustain?)<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">I suspect the problem is with the = string buzzing against the side of the<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">slot.<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Del<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> Perhaps, though I have a = hard time imagining much vibration excursion in<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> that short segment. At that, = how difficult or more expensive is a wider<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> slot, as long as you're = cutting one anyway? It's not like it will cost<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> anything important in = rigidity. A grooved center rod would help too,<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">though<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> it would cost a bit more to produce.<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> Ron N<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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 cite="" type="cite">Del<BR></BLOCKQUOTE></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><TT>--</TT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><FONT face="Times New Roman" = color=#0000ff size=+1><B>OVERS PIANOS - SYDNEY</B></FONT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><FONT color=#000000><I>   </I></FONT><FONT = color=#0000ff><I>Grand Piano Manufacturers</I></FONT><FONT color=#000000><BR>_______________________</FONT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><FONT color=#000000 = size=-2><BR></FONT><FONT color=#000000>Web http://overspianos.com.au</FONT></BLOCKQUOTE> <BLOCKQUOTE cite="" type="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" color=#0000ff size=+1><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 color=#000000 size=-2><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>