<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY> <DIV><FONT color=#008000>Comments below:</FONT></DIV> <DIV><FONT color=#008000></FONT> </DIV> <DIV><FONT color=#008000>Terry Farrell</FONT></DIV> <DIV> <SPAN id=__#Ath#SignaturePos__></SPAN> </DIV> <DIV>----- Original Message ----- <DIV>From: "Bill Ballard" <<A href="mailto:yardbird@vermontel.net">yardbird@vermontel.net</A>></DI= V> <DIV>To: "Pianotech" <<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>></DIV> <DIV>Sent: Saturday, April 19, 2003 9:57 PM</DIV> <DIV>Subject: Re: Curved Long Bridges</DIV></DIV> <DIV><BR></DIV> <DIV>> At 8:04 AM -0400 4/19/03, Farrell wrote:<BR>> >We were = talking about a bridge from a piano with a well-designed <BR>> >stringing = scale and long bridge (what other kind would you put into <BR>> >a = piano?). There was an inherent assumption that hockey sticks <BR>> >belong = on the ice, and not in a piano! Yes, axe that curve off the <BR>> >low = tenor end of that stick and see how it balances.<BR>> <BR>> Two points: = Don't let your oeile get trompled.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>What on earth is an oeile?</FONT></DIV> <DIV> </DIV> <DIV>> That upright long <BR>> bridge is actually straighter = than a Steinway O's. In the picture, <BR>> the tenor bridge is the = closest.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Most (I think likely all?) well designed = piano scales do not have any sort of a hockey stick curve at the tenor end of = the long bridge. It gets fairly straight in that area. The curve to the bridge is = in one direction only.</FONT><BR> <BR>> Nomer Doo: When you talk of = balancing, I'm assuming that's along its <BR>> length (as pictured). It's a long = stick; find its balance point and <BR>> both end will float in the air. I'm = not sure that getting both ends <BR>> to float in the air needs to be made any = easier by editing the curves <BR>> at the ends.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Thats just the point. The bridge from a well = designed scale will only have the curve in one direction. In that way, the bridge forms an arc of sorts (portion of a circle - not = that is is really circular though) - like the example I gave a while back with = the donut sitting on top of the basketball. Put the pencil under the middle = of the arc, and the mid section of the arc lifts up, but the two ends remain in contact with the surface of the table = or whatever it was laying on. If you need a picture, I will send one.</FONT><BR> <BR>> I just got finished realizing that any = crown in a ribbed board is <BR>> incidental, and not required for support of the = string load.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Where did this come from? The crown is = usually designed in, not incidental.</FONT></DIV> <DIV> </DIV> <DIV>> This <BR>> meant that the underside of the bridge = didn't need to be fitted to <BR>> match board curvature (crown) parallel to the = board and bridge. What <BR>> remains is any extent to which the bridge may, in = its path down the <BR>> board, cross the "continental divide" (as 'twere), and = thus need to <BR>> have its bottom shaped to match this uphill/downhill = contour. If this <BR>> isn't done, I could imagine that the flat-bottom (for = lack of a <BR>> shorter word) bridge would would end up twisted in its cross = section. <BR>> Then the bridge would no longer be plumb to the string plane, = but <BR>> rather to the whatever point in the board's curvature you chose = to <BR>> measure it.</DIV> <DIV> </DIV> <DIV><FONT color=#008000>Not really sure where you are going with this = stuff.</FONT><BR> <BR>> Maybe I pulled this thinking out of the = oven too soon, maybe I should <BR>> put it back in.<BR>> <BR>> >BTW: = Is that a hunk of granite on that table? Where did you get it? <BR>> >$$? = Sorry, I couldn't resist - its the old geologist in me.<BR>> <BR>> That's = right. One of two panels. That one 30"x60"x2.5", and the other <BR>> 42"x78"x(2.5~3.5") Rescued from an abandoned granite quarry in S. ME = <BR>> 20 years ago. But that's a story for another time. Mark Dierauf, <BR>> = who's also on the list, might chime in on this one (seeing as how the <BR>> = statute of limitations has long gone).<BR></DIV> <DIV><FONT color=#008000>Nice granite chunks, for sure. Darn good = way to make a flat table!</FONT><BR> <BR>> Bill Ballard = RPT<BR>> NH Chapter, P.T.G.<BR>> <BR>> "I go, two plus like, three is pretty = much totally five. Whatever"<BR>>      ...........The = new math<BR>> +++++++++++++++++++++<BR>> _______________________________________________<BR>> pianotech list = info: <A href="https://www.moypiano.com/resources/#archives">http://www.ptg.org= /mailman/listinfo/pianotech</A></DIV></BODY></HTML>