<!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 6.00.2600.0" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV>Dale:</DIV> <DIV> </DIV> <DIV>My conversations and classes that I attended with = David Hughes (if I remember correctly) led me to believe that he prestressed the = board under the central plate strut by 3 mm and then set the bearing dime, nickel, = quarter, in low tenor, mid-range, treble, respectively.  That seemed to = pretty much be his method without additional measurement.  I'm sure he arrived = at this method by much experience, but he didn't seem to sweat it beyond that.</DIV> <DIV> </DIV> <DIV>David Love</DIV> <BLOCKQUOTE style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style="FONT: 10pt arial">Dale:</DIV> <DIV style="FONT: 10pt arial"> </DIV> <DIV style="FONT: 10pt arial">----- Original Message ----- </DIV> <DIV style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black">From: <A title=Erwinspiano@AOL.COM href="mailto:Erwinspiano@AOL.COM">Erwinspiano@AOL.COM</A> </DIV> <DIV style="FONT: 10pt arial">To: <A = title=pianotech@ptg.org href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV> <DIV style="FONT: 10pt arial">Sent: January 19, 2002 5:46 = PM</DIV> <DIV style="FONT: 10pt arial">Subject: Re: Baldwin accu-hitch = pins</DIV> <DIV> </DIV>Subj:Re: Baldwin accu-hitch pins = Date:1/19/2002 3:28:10 PM Pacific Standard Time From:<A = href="mailto:davidlovepianos@earthlink.net">davidlovepianos@earthlink.n= et</A> Reply-to:<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To:<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent = from the Internet <BLOCKQUOTE></BLOCKQUOTE>        = Dale: <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">I believe the Baldwin instructions call for setting the = bearing at zero degrees to begin with.   After pulling the piano = to pitch you then start at the bottom of the tenor (no bass strings = yet).  Tap down note 21 - 35 to 1/2 degree, 36 - 53 to 1 degree and 54 - 88 to = 1 1/2 degrees--in that order. </BLOCKQUOTE> >>>>>>>&gt= ; Thanks David now this is starting to make some logical sense, to me at = least. Wow 1/2 half degree isn't much for starters on a board with real crown = values. An easy way to calculate 1&1/2 degrees of bearing is to measure = the rear string length from the front bridge pin to the aliqot i.e. measure any = tenor back scale length say of 6 inches. Multiply by.026 = .156". So 1/2 = degree would only be .50. It would be easy to deflect the whole central = portion of the  board by that much by just leaning on it with hand pressure. = By the way 1 degree is calculated by .017 times the length. Thus, the 1 1/2 degrees that you set the = upper teble range to is on a semi-compressed <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">board, at least to the degree that setting the bearing = on the previous sections will compress it. </BLOCKQUOTE> >>>>> True   So notes 54 = -88 are actually set at greater than 1 1/2 degrees if you were <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">measuring from the point before the board had any = downward pressure it.</BLOCKQUOTE> >>>>Yes but the net result would be = less than that because of board compression. This would be barely enough = pressure to"take the slack out of the board " as John Hartman says ,let alone = utilize all the crown that was so carefully built into it. What I want is to = press the board fimly so that it is spring loaded enough to push back against = the string. When this happens the board are in firm resistance to each = other and this is when I believe that optimum power/sustain are approached, = especially in new fully crowned boards.  With respect to my method of = setting bearing ,at the point the Baldwin boards bearing is set is the point = at which I would probably start adding 1 1/2 degrees of bearing but not = exeeding 1/4" on the longest string = lengths.        Moreover, if you were to go string by string, the measurable bearing = after you got <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">to the top would be something less than your initial target.  The question seems to be, when the board is already = set with some bearing, but perhaps the wrong bearing, how do you approach the = problem?</BLOCKQUOTE>   >> I agree.  A bit of a sticky wicket   Can you simply go through and correct the = bearing to read 1/2, 1, 1 1/2 degrees <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">respectively?  I often wonder whether we fret over = this a bit too much</BLOCKQUOTE> .      = >>>>>>I respectfully have to say I don't think so. If you have the chance to = change one of these and  improve it in the process you'd answer your own = question.    I've heard good sounding boards with a variety of downbearing measurements.  = <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE">Though I have not heard one of David Hughes' boards, the = impression I get from him is that we sweat over this a bit more than = is necessary.  The factors that go into a good sounding board are obviously greater than just the bearing measurements.  Teasing = out the variables is difficult, to say the least.</BLOCKQUOTE> >>>>Yes but is bearing where you'd have me sweat less on if it was your board = project? There are several obvious primary factors that we all consider essential. = Good construction,materials ,crown ,adequate bearing,reg. and of course voicing.      = Davie Hughes and have talked bearing at length and our methods are very similar if = not identical. His boards sound very fine. Wonderful sustain and = color.  I have to say he may have been understating it a = bit.     Bearing/plate set up setting in my shop takes a good long time as I = consider it a VERY primary and critical component of making the whole system = work well. I've looked at a lot of  torn a part pianos over  the years = and 90% of those that I liked the best had significant even  measurable = bearing and crown. The other 10% are anomallies. I.e  Board stiffness due = to mass not crown or bearing    I"ve also had the advantage of a = few less than stellar results (which is aggravating) that I could lay at the = feet of uneven or inadequate bearing/panel compression that when remedied the = tonal results were greatly improved.   To me a new board with = inadequate bearing is like a fine new car wth only a gallon of gas in the tank. = It won't take you very far.   Thanks again for enlightening me to the = Baldwin method. I now have a better grasp of there concept though I consider = it misguided.       =      Best---Dale Erwin <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px = solid; MARGIN-RIGHT: 0px" TYPE="CITE"> David = Love <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE">----- Original Message ----- From: <A href="mailto:Erwinspiano@AOL.COM">Erwinspiano@AOL.COM</A> = To: <A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> = Sent: January 19, 2002 2:07 PM Subject: Re: Baldwin accu-hitch = pins In a message dated 1/19/2002 11:23:14 AM Pacific = Standard Time, <A = href="mailto:RNossaman@KSCABLE.com">RNossaman@KSCABLE.com</A> writes: <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE">Subj:Re: Baldwin accu-hitch pins = Date:1/19/2002 11:23:14 AM Pacific Standard Time From:<A = href="mailto:RNossaman@KSCABLE.com">RNossaman@KSCABLE.com</A> Reply-= to:<A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> To:<A = = href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> Sent from the Internet > >  Ron = (somebody) tell me what I'm missing on the acujust in a way I can = absorb > it. What's that you say? not possible. hmmmmmmm >        >        Dale Erwin Dale, I'm not sure what the question is = here. Like you have adjusted plate height to fine tune bearing, you can = do the same thing section by section, or note by note with the hitch = pin adjustment. Your initial plate height is determined just like = you would normally do it, only your back scale target isn't the = top of an aliquot, but a vertical position on the = hitch.</BLOCKQUOTE> Hi Ron   Ok I get this sort of but the place where I'm hung = up is that as you start driving the strings down on the hitch your = bearing increases as does the amount the board is compressing as you go. = Just like in pitch raising. So how do you know when enough is enough and = when do you know that there is enough ,of the desired deflections so often = discussed. Meaning a 1 to 11/2 degree angle of deflection depending where in = the scale we are talking about. Dale If you shoot for = somewher <BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff = 2px solid; MARGIN-RIGHT: 0px" TYPE="CITE">around 4mm up the hitch as a target, you have some = room for final vertical positioning as you find necessary. </BLOCKQUOTE> Ron    Once again how could a person = possibly know what the final position is? Does that = make sense?       Ron      Uhhh not yet Ron.  I must = be coming at this from a really strange angle of comprehension. I = took Stacy Yokums class in Reno and he couldn't answer my question either. I = wasn't the only one asking it either.   Let me try another way by = explaining where I'm coming from.   Ok Take a new board = and new set of too tall bridge caps. Install plate and cut the tops so = that without any load on the board you have a 1 degree angle of = deflection in the lower tenor rising to 1& 1/2 degrees thru the tenor = right  up to note 88. Now install all the strings from the tenor /bass break = to 1st capo section at. Tune these up to pitch. Before you string further = take a bearing string and check the remaining deflection. Meaning once = again that the soundboard is sinking under down bearing pressure as we go. If = done this way I can guarantee an insuffiecnt amount of bearing to drive = the treble in your shiny new board. The bearing string will probably = touch bridge and aliqot at the same time or almost but that isn't enough = bearing for trebles.     In fact I you can't even read = much deflection with the string at all. Unfortunately this is the very = method Nick Gravagne outlined in the journal many years ago and it = doesn't work unless you pre- stress the board some. He didn't correct or I = should say amend it and I only found out he was using pre stressing and the 1 = 1/2 degree angle of deflection in one of my conversations with him a = year or so ago.      MY point oh yes is how in the = acujust system does one approximate total and adequate deflection with any = confidence that your not creating the problem I described above.    My answer so far is that you can't. Its more of a = guesstimate than I'm willing to make until somebody can give me = some clarification.   Does this help to see my angle of = deflection!!!!!!!         &nbs= p;  =            &nb= sp;         Dale Erwin </BLOCKQUOTE> </BLOCKQUOTE> </BLOCKQUOTE><= /FONT></BODY></HTML>