This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment 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?=20 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.=20 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.=20 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.=20 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.=20 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.=20 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.=20 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.=20 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.=20 Oh, yes. They cost about 30% more than regular Diamond pins.=20 Paul Larudee=20 David Skolnik wrote:=20 Paul, Joe-=20 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:=20 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.=20 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).=20 Share your thought, and how much did you pay for them (the pins, that = is)?=20 David Skolnik=20 =20 =20 =20 At 09:23 AM 05/14/2001 -0700, you wrote:=20 Paul,=20 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.=3D.265"). Hope this clarifies for you.=20 Regards,=20 Joe Garrett, R.P.T.=20 ----- Original Message -----=20 From: larudee@pacbell.net=20 To: pianotech@ptg.org=20 Sent: Monday, May 14, 2001 7:40 AM=20 Subject: Re: Ditch the tuning pin bushings=20 Del & David,=20 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.)=20 Paul Larudee=20 =20 =20 David Skolnik wrote:=20 At 11:22 PM 05/13/2001 -0700, you wrote:=20 =20 Another thought though; someone mentioned to me the problem of = restringing=20 with oversize pins -- something I'd not really thought about = since we don't=20 do this.=20 Del Del-=20 Could you make clear what size pin qualifies as "oversized", = assuming that 2/0 was the original? Thanks.=20 David Skolnik=20 =20 =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/41/99/38/05/attachment.htm ---------------------- multipart/alternative attachment--
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