<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=iso-8859-1" = http-equiv=Content-Type> <META content="MSHTML 5.00.2919.6307" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff>   Paul wrote Rather, I was picking up on Del's comment about never using oversize = pins and the question of open vs. closed blocks.  He's not the only = one who refuses to use oversize pins, and why not? I can think of two good reasons.  Presumably we want tuning pins = to be as narrow in diameter as possible because a) the amount of leverage = (torque) exerted by the string tension increases with each increase in diameter = (radius) and b) the amount of string moved per unit of rotational movement also = increases accordingly.  Smaller caliber pins are therefore easier for the = technician to turn (and less easy for the string tension to turn), and permit = smaller, more precise string movements, all other factors being equal.  Paul ,the other reason is that when Del = Or I or any rebuilder says that we don't install oversize pins the third answer or consideration is that usually we're putting in an entire new belly = system and we want and beleive that good practice dictates a new block.Afterall our = idea is that we're starting the life of the piano over.   Now I see nothing wrong with = repinning from a no.2 to a 3 pin in an original well preserved block andI do that on = occasion with very good results.But no.3 are my limit.    Best, Dale Erwin        The fact that they are less easy for the string tension to turn = also makes the tension more stable.  I don't think I'm saying anything = new here, but if there are other reasons not to use oversize pins (in principle, = not in practice), I would be interested to know. On the other hand, there are also reasons not to use pins that are = too narrow.  Even if pins were made of a material stronger than they = are, we would not want them to be so narrow that they would slice through the = pin block or deform the holes.  We need enough surface area so that the = integrity of the block is not in jeopardy.  Another consideration is = flexion.  Narrower pins will flex more than wider ones.  I agree that some = flex is necessary, but generally speaking, I consider this something to keep to = a minimum.  I would rather maximize the ability to change tension in = the smallest possible increments through changes in pin setting (rotational = movement in the block) than to depend upon flagpoling to modify pitch in small = amounts. On the other hand, flagpoling becomes more feasible when string = geometry is designed in conjuction with it.  When there is more friction at the = bearing points, flagpoling becomes more necessary to overcome it, and at the = same time the friction helps to prevent changes in tension that might otherwise = result from a pin that flexes too easily.  However, I think that this is a = second best approach, and the best is still to have a design that permits finer = pin setting and depends less upon flagpoling. One of the advantages of open face pin blocks is that they achieve = exactly that.  The force of the string tension is much closer to the = fulcrum, which makes flagpoling less of a factor.  This permits the use of = narrower pins, which is presumably why 1/0 pins are standard in this design.  On = the other hand, 2/0 pins are pretty much standard in closed blocks, where 1/0 = would generally be too flexible.  Unfortunately, this distances us from = the advantages of narrower pins. Obviously, oversize pins remove us even farther.  That is why I = designed my pins.  They are oversize where they need to be, but the same = size as standard pins at the coils, and therefore with the same torque = characteristics as standard pins.  It is even possible to reduce from a size 2/0 to = a 1/0 without putting in a new pin block. Although my pins are designed for repinning, whether as single pins, = sets of bass strings or an entire piano, the same principle can be applied to = new instruments, allowing the size at the string coils to be divorced from = the size that goes into the block.  This gives more options with regard to = torque, flexibility, contact area in the block, etc. Oh, yes.  They cost about 30% more than regular Diamond pins. Paul Larudee David Skolnik wrote: <BLOCKQUOTE TYPE="CITE"> Paul, Joe- Joe, it sounds to me as though Paul is describing something = different. Paul, I guess we could find out your special reason directly from you, = or by getting in touch with one of two Davids.  I'm not clear on the engineering, however, for starts the implication here is that the = benefit of the smaller pin resides in its smaller string coils rather than the = total surface area in contact with the block.  I'm not clear as to why = you would want additional stiffness in that area of the pin unless you = think the pins are being pulled forward due to insufficient surface area (part = of pin in the block itself) or due to excessive flexing.   If you are = talking about repinning with these, two problems come to mind: 1) Given = the current discussion of pins already in contact with the plate, it seems = to me you would have a bit of a problem installing them, unless you were to = drive them in from the bottom of the block.  That would certainly be = something to write about. 2) As a few on this topic have mentioned, and with = whom I agree,  a small degree of flex is a useful fine tuning = tool.  It would seem that, by stiffening the pin up to the coils, and then = reducing the size at the top, you would be directing the flex force to one, already = weakened area of the pin (string hole). Share your thought, and how much did you pay for them (the pins, = that is)? David Skolnik       At 09:23 AM 05/14/2001 -0700, you wrote: <BLOCKQUOTE class=cite cite type="cite">Paul, Many years ago, Piano Manufacturers actually used a tuning = pin like you describe. It is called a tapered tuning pin. They had many = advantages. One of which is, slight tapping of one that is considered loose, = fixed the problem. These pins were approx. #1 pin size at the bottom and = approx. 3/0 at the top. (that is not a typo: #1 tuning pin dia.=.265"). Hope = this clarifies for you. Regards, = Joe Garrett, R.P.T. <BLOCKQUOTE class=cite cite type="cite">----- Original Message = ----- From: <A href="mailto:larudee@pacbell.net">larudee@pacbell.net</A> = To: <A href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> = Sent: Monday, May 14, 2001 7:40 AM Subject: Re: Ditch the = tuning pin bushings Del & David, What about a tuning pin that is oversize from just under the = coils down and size 1/0 or 2/0 from there up?  That would give added = stiffness to the pin in the portion that passes through the webbing without sacrificing the better torque and smaller string coils that you = get with standard size pins.  It also allows reuse of the old pin = block (if it is in good condition) while still retaining the benefits of = standard size pins.  (David Love and David Ilvedson know that I have a = special reason for asking this question.) Paul Larudee     David Skolnik wrote: <BLOCKQUOTE class=cite cite type="cite"> At 11:22 PM = 05/13/2001 -0700, you wrote:   <BLOCKQUOTE class=cite cite type="cite">Another thought = though; someone mentioned to me the problem of restringing with oversize pins -- something I'd not really thought about = since we don't do this. Del</BLOCKQUOTE> Del- Could you make clear what size pin qualifies as "oversized", assuming that 2/0 was the original?  Thanks. David Skolnik   =  </BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY>= </HTML>