<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=us-ascii"> <META content="MSHTML 6.00.2900.3354" name=GENERATOR></HEAD> <BODY style="WORD-WRAP: break-word; webkit-nbsp-mode: space; webkit-line-break: after-white-space"> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>Fred~</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>Yes, one of the things I have heard is that the threads increase the surface area of the pin in contact with the sides of the hole in the pinblock.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>Catherine Bielefeldt, in her "Wonders of the Piano" book, offers that bluing contributes to the holding power of the pins because the oxidizing process tends to make them "stickier".</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2> </FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>In my experience, AMSCO pins, in their last years in business, were some of the worst as far as tolerances. They would vary as much as .005 -on the same pin!</FONT> <FONT face=Arial color=#0000ff size=2>Plus they were often oval in cross-section. Nippon Denro pins were much better machined, but still varied as much as .002" (or sometimes .003") within a set, and .001 to .002" sometimes on a given pin. I hear from my rebuilding friends that Diamond/Klinke pins have very fine tolerances, within .001 or less. I think oval pins (in cross-section)  bother me the most, and would probably be the most problemmatic over the long run.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>Yes I agree that there are many factors involved in how pins hold and for how long. And some rebuilders are penny-wise when it comes to buying the most expensive pins, but pound foolish when it comes to pinblocks, either by not getting good material, or by drilling it carelessly.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>On the tapered pins - I have restrung a few pianos built around 1880 to 1900 or so that had tapered pins.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>The pins, when I finally figured out how to measure them- (they seemed to have a great variation in tolerance, until I realized they were tapered and I that had not been consistent in where I measured them along the thread) -were tapered along the entire length of the thread. An 1890 Hemme and Long upright had I guess what you could call tapered #1/0 pins: they went from .276 at the top end of the thread to .259 at the bottom, were blued pins, and were 2 1/4 inches long. One of the things I decided was that putting a parallel sided pin in a tapered hole was going to cause problems, it would probably be super tight at the bottom end of the hole and relatively loose at the top, and as I was restringing using the existing block, (old dry wood) I hesitated at the thought of possibly splitting the pinblock out at the bottom of the hole by driving a new oversize pin that would be okay for the top of the hole but much too large for the bottom. Ultimately I think what I did was drill the holes out with a parallel sided bit that just fit the top of the hole (slightly under .276 - it seems even after extracting the old pins the holes were still a bit smaller than the pins.) Then I used new # 2 pins or # 3's, whichever felt the best.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>Yes, you're right, it probably required a good deal of extra effort and expense to drill tapered holes at the factory, so this was probably one of the first operations to be eliminated in a cost-cutting effort. Tapered holes would have had to have been drilled to exactly the right depth for the tapered pins to fit properly, and I imagine this was not easy to achieve on a consistent basis. I think that is one of the reasons I ultimately decided to convert this piano to parallel sided holes and pins.</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>I wonder where Bosendorfer gets their tapered pins. And what technicians do when they have to replace a Bosie pinblock? Would they have to get a tapered bit from Bosendorfer? Or would they just convert to parallel sided holes and pins?</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2>~Kendall Ross Bean</FONT></SPAN></DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008><FONT face=Arial color=#0000ff size=2></FONT></SPAN> </DIV> <DIV dir=ltr align=left><SPAN class=342582600-09072008> <DIV align=left> <DIV><FONT face=Arial size=2><SPAN class=533361603-16112007>PianoFinders</SPAN></FONT></DIV> <DIV><FONT face=Arial size=2><SPAN class=533361603-16112007><A title=http://www.pianofinders.com href="http://www.pianofinders.com/">www.pianofinders.com</A></SPAN></FONT></DIV> <DIV><FONT face=Arial size=2><SPAN class=533361603-16112007>e-mail: <A title=mailto:kenbean@pianofinders.com href="mailto:kenbean@pianofinders.com">kenbean@pianofinders.com</A></SPAN></FONT></DIV> <DIV><FONT face=Arial size=2><SPAN class=533361603-16112007></SPAN></FONT> </DIV> <DIV><FONT face=Arial color=#0000ff size=2><SPAN class=533361603-16112007><EM>Connecting Pianos and People</EM></SPAN></FONT></DIV></DIV></SPAN></DIV><BR> <DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left> <HR tabIndex=-1> <FONT face=Tahoma size=2><B>From:</B> Fred Sturm [mailto:fssturm@unm.edu] <BR><B>Sent:</B> Monday, July 07, 2008 7:38 PM<BR><B>To:</B> College and University Technicians<BR><B>Subject:</B> Re: [CAUT] Tuning Pin Questions<BR></FONT><BR></DIV> <DIV></DIV> <DIV>On Jul 7, 2008, at 2:58 PM, Kendall Ross Bean wrote:</DIV> <BLOCKQUOTE type="cite"> <DIV><FONT class=Apple-style-span color=#000000><BR></FONT> <DIV><SPAN class=909222614-07072008><FONT face=Arial><FONT size=2><SPAN class=533392320-07072008></SPAN></FONT></FONT></SPAN> </DIV> <DIV><SPAN class=909222614-07072008><FONT face=Arial><FONT size=2><SPAN class=533392320-07072008>I would love to see a discussion by parties hopefully much more knowledgeable than myself, about why these silly pins are the way they are today.</SPAN></FONT></FONT></SPAN></DIV> <DIV><FONT face=Arial size=2><SPAN class=909222614-07072008></SPAN></FONT> </DIV></DIV></BLOCKQUOTE> <DIV><BR></DIV>Hi Kendall, <DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>I don't know how knowledgeable I am on this subject, but I think the answer to most of your questions can be probably summarized in two words: aesthetics and salesmanship. A similar example is key bushing cloth, which we all "know" should be white inside. Maybe at some point there was a reason (eg, the dye didn't penetrate during the processing - only when the felt was of sufficient density), but now they go to some trouble to meet the expectation. It is starting to change: Steinway now has white key bushing cloth (very recent - probably EU green regulations or PR, as it initiated in Hamburg). I think the hype about "bluing" is very similar, and done to try to sell more pins to gullible technicians. That's my own skeptical opinion, based on what experience I have. But maybe someone else with more varied experience can tell us why one kind of bluing is better than another, and why bluing is better than its absence. </DIV> <DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>I think that the real difference in tuning pins (available stock - all being strong enough to stand the torque of being turned while tuning) is manufacturing tolerances. Are they round within .001"? Are all the pins in a set within .001" of one another? If so, you've got a good set. The pinblock will make much more difference: material? number and direction of plies? glue? drill bit used? control of drilling speed? to name some of many of the factors that go into determining if pins hold well and turn well.</DIV> <DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>Threads are for pin removal. They also add to the surface area, so they impact the friction with the block. Smooth pins work okay in harpsichords. I don't know if the extra torque of pianos would change that. But I wouldn't want to experiment, since I want the pins to be removable. "Reverse thread" is generally accepted as hogwash salesman claim. It is probably a side-effect of the method of cutting threads, where some filings are laid down with a direction. I don't think it actually wears out a block, though I can see where that opinion would come from. I think the amount of cutting done in a tuning pin hole would be limited rapidly by being clogged by wood fiber. In any case, I don't think pianos with such pins have a unique behavior I can identify, though really one would have to follow a piano through a period of years to come to a conclusion, and I haven't done that (not with conscious intent, knowing what I had to begin with and observing to see what happened over time).</DIV> <DIV><SPAN class=Apple-tab-span style="WHITE-SPACE: pre"></SPAN>Tapered is, I think, a vestige of times when blocks were solid, and drilling tolerances not that tight. To work really well, you need tapered drill bits to drill holes with the same taper as the pin. The experience I have with tapered pins is in harpsichords. A lot of them, the pins aren't truly tapered, they are cylindrical to the bottom couple centimeters, then that lowest portion is tapered pretty acutely. Not a very good design in my experience. They are often hard to remove, and don't really get much tighter driving them in further. I have only very limited experience with truly tapered pins, and I don't know if the holes were drilled tapered. In any case, I don't the the possible gains outweigh the extra expense.<BR> <DIV apple-content-edited="true"><SPAN class=Apple-style-span style="WORD-SPACING: 0px; FONT: 12px Helvetica; TEXT-TRANSFORM: none; COLOR: rgb(0,0,0); TEXT-INDENT: 0px; WHITE-SPACE: normal; LETTER-SPACING: normal; BORDER-COLLAPSE: separate; orphans: 2; widows: 2; webkit-border-horizontal-spacing: 0px; webkit-border-vertical-spacing: 0px; webkit-text-decorations-in-effect: none; webkit-text-size-adjust: auto; webkit-text-stroke-width: 0"> <DIV style="WORD-WRAP: break-word; webkit-nbsp-mode: space; webkit-line-break: after-white-space"> <DIV>Regards,</DIV> <DIV>Fred Sturm</DIV> <DIV>University of New Mexico</DIV> <DIV><A href="mailto:fssturm@unm.edu">fssturm@unm.edu</A></DIV> <DIV><BR class=webkit-block-placeholder></DIV></DIV></SPAN><BR class=Apple-interchange-newline></DIV><BR> <DIV> <DIV><BR></DIV></DIV></DIV></BODY></HTML>