<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=utf-8"> <META content="MSHTML 5.50.4134.600" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV><FONT face="Lucida Sans" color=#000080></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B> <A title=Erwinspiano@AOL.COM href="mailto:Erwinspiano@AOL.COM">Erwinspiano@AOL.COM</A> </DIV> <DIV style="FONT: 10pt arial"><B>To:</B> <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> ; <A title=Davehugh@msn.com = href="mailto:Davehugh@msn.com">Davehugh@msn.com</A> </DIV> <DIV style="FONT: 10pt arial"><B>Sent:</B> January 22, 2002 8:49 = AM</DIV> <DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Baldwin Accu-Just = Hitch Pins--General Information</DIV> <DIV><FONT face="Lucida Sans" color=#000080></FONT><BR></DIV> <DIV><FONT face=arial,helvetica><FONT lang=0 face=Arial size=2 = FAMILY="SANSSERIF">In a message dated 1/21/2002 10:35:32 PM Pacific = Standard Time, <A = href="mailto:pianobuilders@olynet.com">pianobuilders@olynet.com</A> writes:<BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" = face=Arial color=#000000 size=2 FAMILY="SANSSERIF"><BR></FONT><FONT = lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=2 FAMILY="SANSSERIF">   I think possibly you were confused = about the order of subjects under discusion over the weekend. They did get = convoluted and went from one thing to another. The Baldwin board specs were = hashed out some and then it went on to the topic of setting crown in new boards, = so you may not have picked up on the sequential discussions of this thread. = That's why your post struck me the way it did. I didn't mean to necessarily = relate those downbearing numbers to the baldwin system but to a fairly = typical 60ft. crowned board with rib dimensions the same or similar to what ever the = original heights were. This type of board is pretty common in shops = across the country (as you know) and is probably where those asking the question = will start at. Hence my reply. Perhaps my post was confusing.<BR>      The prestressing method = itself was what I wanted to make a point of and as you say the bearing values = will change given a host of different factors. Although this method is old = perhaps there other methods as well that I would certainly enjoy hearing discussed.<BR>     I apologize for bristling a = bit. The rest of you post was well taken and clear = enough.<BR><BR>         &nbs= p;           &nbsp= ;            =             &= nbsp;         Best--Dale Erwin</FONT></FONT></DIV></BLOCKQUOTE> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>But, Dale, I was aware that the thread had gone = on, hence the new title on my post; <EM>Baldwin Accu-Just Hitch Pins--General Information</EM>. </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>The comment you bristled over was intended to = address what I see as an problem in which the reader ends up applying = downbearing numbers given by a respected rebuilder as gospel in situations in which = they really don't apply. If you've not yet seen this happen, you will. Do you = not vary these figures when confronted with a piano having a particularly = long or short backscale? Are they the same for each make or brand of piano that = you do? Are they the same for a Model S as they are for a Model D? Do you really = set A-1 at 0 for both? Are the rib height and width always the same? What about = a 6' 1" piano with 9 ribs vs. a 6' 1" piano with 11 ribs? Is your shop climate controlled? What if it weren't? What about the rebuilder in the south = bellying a board in the summer? Without air-conditioning? Or in North Dakota. With = heat! </FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>As may be, life's not a constant and my post was = intended to point out a few of the idiosyncrasies of the Baldwin Accu-Just hitch pin = system and to remind the reader that not all pianos--in particular, Baldwin = pianos using the Accu-Just hitch pin system--are constant either.</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <DIV><FONT size=2>Regards,</FONT></DIV> <DIV><FONT size=2>Del</FONT></DIV> <DIV><FONT size=2></FONT> </DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000080 2px solid; MARGIN-RIGHT: 0px"> <DIV><FONT face=arial,helvetica><FONT lang=0 = style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=2 FAMILY="SANSSERIF"><FONT = face="Lucida Sans" color=#000080 size=3></FONT> </DIV> <DIV><BR></DIV> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE"> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE"> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE"><FONT face="Lucida Sans" color=#000080 size=3></FONT><BR></FONT><FONT lang=0 = style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 size=2 FAMILY="SANSSERIF">Dale, = Carl, et al,</FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" = face=Arial color=#000000 size=2 = FAMILY="SANSSERIF"><BR>.<BR><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 = size=2 FAMILY="SANSSERIF">Mostly, how much loading any specific = soundboard must have is a function of how massive and how stiff the soundboard = assembly is. This is not a universal constant. Dale’s string = deflection numbers would not work[at] all for one of our boards. As to whether they = would work for one of Baldwin’s current boards—I cant = say. With the Accu-Just system Baldwin has used a fairly light crown = radius—</FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=2 FAMILY="SANSSERIF"><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=2 = FAMILY="SANSSERIF"></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE><BR></FONT><F= ONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial = color=#000000 size=2 FAMILY="SANSSERIF">Del--Just so it doesn't appear that you're = dismissing my downbearing deflection no. derived from the experience myself and = others out of hand, let me Re-</FONT><FONT lang=0 style="BACKGROUND-COLOR: = #ffffff" face=Arial color=#000000 size=2 = FAMILY="SANSSERIF"><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=2 FAMILY="SANSSERIF"> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE"> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE">state that these no.s are real do work well in = NON--REDESIGNED soundboards, which I must point out most of us are doing. I think = I was fairly specific as to the type of replacement board application = that these numbers do commonly work in. </FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=3 FAMILY="SANSSERIF"><BR></BLOCKQUOTE><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 = size=3 FAMILY="SANSSERIF">No, I'm not dismissing them at all. And I'm = certainly not dismissing your experience. I thought I was being pretty specific = when I said your downbearing numbers wouldn't work for our soundboards. And = they may not work for Baldwin boards--which is what the original = discussion was about if I recall correctly. Anyway, my apology if I wasn't specific = enough--I'm just trying to point out that these numbers are specific = to the type and design of the boards you put in. They may or may not work = well for the boards someone else puts in using some (perhaps only slightly) = different procedure. Or some different combination of materials. </FONT><FONT = lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=3 FAMILY="SANSSERIF"><BR><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 = size=3 FAMILY="SANSSERIF">There are lots of variables that go into = setting up a soundboard system, including determining the amount of string = loading on the soundboard. The numbers you and others are quoting are numbers that = work well for you. You've done a lot of boards and you're comfortable = with them. But they are not universal numbers for all soundboards and for all = pianos though they typically get used that way. When the question is asked, = "How much downbearing should there be on a new soundboard?" I'm not sure = we can answer without either asking or giving a bit more information, as = you're doing below:</FONT><FONT lang=0 style="BACKGROUND-COLOR: = #ffffff" face=Arial color=#000000 size=3 FAMILY="SANSSERIF"><BR><BR></FONT><FONT = lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=2 FAMILY="SANSSERIF"><BR><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 = size=3 FAMILY="SANSSERIF"> <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE"><BR>  These values of downbearing  work well = for me on 60ft. rib crowned boards(treble radius are tighter) but with = some modification of the system of prestressing, I suggest the = procedure could be applied to many if not most soundboard systems that exhibit = some stiffness as they're being test loaded. Obviously totally flacid = or under crowned systems woulf require a different approach.<BR>  = Perhaps you'd like to share what values you consider workable in a = non-redesigned rib crowned soundboard system ? Or in your design system for that matter.<BR></BLOCKQUOTE><BR></FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 = size=3 FAMILY="SANSSERIF">I do so in classes I give on the subject. But = without being able to illustrate and discuss the design of the soundboard = the numbers wouldn't mean much. Let's just say that they have somewhat = more flex in them than you're probably used to and they have somewhat more = crown, hence the downbearing settings are quite a bit higher than you would = use.</FONT><FONT lang=0 style="BACKGROUND-COLOR: #ffffff" = face=Arial color=#000000 size=3 FAMILY="SANSSERIF"><BR><BR></FONT><FONT = lang=0 style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000080 = size=3 FAMILY="SANSSERIF">Del</FONT><FONT lang=0 = style="BACKGROUND-COLOR: #ffffff" face=Arial color=#000000 size=3 FAMILY="SANSSERIF"><BR></BLOCKQUOTE><BR><BR></BLOCKQUOTE></FONT></FONT>= </BODY></HTML>