<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> <html> <body bgcolor="#FFFFFF"> Good point.  There is a slightly greater danger of this than there would be with ordinary pins.  The larger the size difference between the two portions, the greater the risk.  However, if the pin is that tight, it won't be tunable anyway.  On the other hand, I don't think I would advise a 6.75mm. top on a size 5/0 (7.45mm.) base.  I may be overcautious, but I wouldn't go over a half millimeter difference in diameter (= 1/4 mm. radius).  I haven't done the math on the stress factors. <p>Paul <p>David Love wrote: <blockquote TYPE=CITE><style></style> <font size=-1>Paul:</font> <font size=-1>Because of the difference in diameter between the coil portion and the block portion, is there any danger of shearing the pin off if the pin is too tight in the block?</font> <font size=-1>David Love</font> <blockquote dir=ltr style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 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 href="mailto:larudee@pacbell.net" title="larudee@pacbell.net">larudee@pacbell.net</a></div> <div style="FONT: 10pt arial"><b>To:</b> <a href="mailto:pianotech@ptg.org" title="pianotech@ptg.org">pianotech@ptg.org</a></div> <div style="FONT: 10pt arial"><b>Sent:</b> January 26, 2002 11:54 AM</div> <div style="FONT: 10pt arial"><b>Subject:</b> Re: Tuning Pin Size</div>  David, <p>You are right on target.  Comments below. <p>Paul <p>David Skolnik wrote: <blockquote TYPE="CITE"> Paul - <br>I think you are right.  There has and will be plenty to discuss.  I, at least, have already gotten the Feb issue, and also promise to read it, but some of my concerns date back to a number of months ago when, in response to a particular thread, you first started talking about your pin.  One of these concerns is that, as a way of avoiding block replacement, they are not viable if, as in many of the pianos I see, the original pins are already against the plate, whatever their size.</blockquote> Yep, there's no way my pins will back the holes off away from the plate.  The only good solution there is a new block. <blockquote TYPE="CITE">Second, while I understand (I think) the theory regarding torque and flex, I suspect that other factors, such as lack of quality control of pins, or of the fit between pin and block (whether new or repinned), not to mention too much or too <u>little</u> friction between pin and sounding length of string, have much effect upon tunability than the diameter around which the string coils.</blockquote> These are all extremely important, and there is no way that my pins are designed to compensate for inadequacies in any of these areas.  In fact, one of the cautions I include with the pins is not to overtighten them, which is a problem I find with some restrung pianos.  My pins do not need to be as tight, because of the reduced torque.  Furthermore, the difference between what I call uptorque and downtorque (pulling with or against tension) is less with my pins than with other oversize pins.  Another point is that the design of my pins frees the diameter at the coils to be essentially independent of the diameter in the rest of the pin.  Of course there are limitations of strength, but otherwise very narrow diameters like 6.75mm. are entirely feasible on a base that is as big as you want.  That's the principle that I think would be of use to Steinway.  Finally, Klinke, the manufacturer of my pins and regular Diamond pins makes just about the most precise ones in the business.  I needed that kind of precision for my pins in order to get them perfectly coaxial and cylindrical.  Mic them all you want; they come out virtually identical. <blockquote TYPE="CITE"> Remember two things about pin flex...1) It can be a very useful tool in fine tuning, and 2) it is affected by tightness in the block.   A tight pin with no flex can be as difficult to fine tune as a pin with too much flex, whatever its diameter.</blockquote> Yes, flex can be useful, and some manufacturers rely on it more than others in their design.  I like to minimize it as much as possible because it compromises the pin's function as a stable anchor, and I prefer to achieve tunability by other means, to the extent possible. <blockquote TYPE="CITE">  <p>Now to read your article and find out what you really said.. <br>  <p>David Skolnik <p>At 11:37 PM 01/25/2002 -0800, you wrote: <blockquote class=cite cite="" type="cite">Chances are that at this point we get into "but what about...," in which case I get to rewrite the whole article on line.  I would just as soon wait for the February Journal.  There will probably still be plenty to debate, but at least not the stuff I've already covered in the article. <p>Best regards, <p>Paul</blockquote> </blockquote> </blockquote> </blockquote> </body> </html>