Tuning Pin Size

[David Love]

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Paul:

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?

David Love
  ----- Original Message -----=20
  From: larudee@pacbell.net=20
  To: pianotech@ptg.org=20
  Sent: January 26, 2002 11:54 AM
  Subject: Re: Tuning Pin Size


  David,=20
  You are right on target.  Comments below.=20

  Paul=20

  David Skolnik wrote:=20

     Paul -=20
    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.
  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.=20
    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 little friction between pin and sounding =
length of string, have much effect upon tunability than the diameter =
around which the string coils.
  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.=20
     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.
  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.=20
     =20
    Now to read your article and find out what you really said..=20
     =20

    David Skolnik=20

    At 11:37 PM 01/25/2002 -0800, you wrote:=20

      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.=20
      Best regards,=20

      Paul


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