String breakage

[KUANG]

Dear Jon and list:

On Thu, 10 Apr 1997, Keith A. McGavern wrote:

> >Kuang, > >By 'force' rather than 'torque' are you _bending_ the pins? >
>A big, big mistake.
Not bending, _turning_ (intensionaly).  When you
apply a force, the pin won't turn less it applies an opposite force.
Both forces will become a torque because they are not lying in a straight
line (both forces are parallel, the center of two forces is between the
pin and your hand).

> >Torque is part of the 'setting the pin' process, there is also
I agree that it's part of the process. This is very minimum (setting the
pin) though because the pin is very stiff (other words, a steel pin has
almost no flexibility consider the the stress put on it in a piano).
Most of the setting comes from the fact that the pin was slightly bend
during a tuning process.  The bending can be avoided if the tuner only
applies a torque (I'm sure everyone is getting tired of hearing this
word..).  It bends because the axis of the the resulting torque is not
parallel to the pin hole (I hope you're not confuse).  It's almost
impossible for human to do what I said (we're not machines, are we?).
This means alot of stress on your wrist and thumb and almost _no_ stress
on your arm.

> >setting the string. I don't think you understand enough to

"setting the string" is due to the fact that the "tensions" of a string
has not reached a mechanical equilibrium.  Again, it's because piano
wire streches as tension increases.

> >be tuning yet (just deriving from your posts).
> >I think you need to align yourself with a technician who will
> >direct you in your persuit rather than formulating your own
> >theories and experimenting on school pianos.

I'm only applyin few theories of everyday physics.

> >Jon Page
> >Harwich Port, Cape Cod, Mass. (jpage@capecod.net)
> >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> >>...How do you know if you are
> >>excerting a torque and not force?  Well, hold a tuning pin in the air,
> >>and turn it using a hammer.  If the pin stays stationary, then you're
> >>excerting a torque.  If not, then you're excerting a force...
> >>Kuang Wang
>
> Dear Jon, List,
>
> You must have misread his example.  Maybe I am mistaken, but I think you
> will find after rereading it, you will find that he understands the
> difference between torque and force.  It appears to me he also has a pretty
I think they introduce force and torque in the first course of physics.
No Einstein's special relativity until the 4th semester.
> good handle on some of the aspects of piano work.  And what better place
> than school pianos to experiment .  The first three years of my piano
> experience revolved around 80 + school pianos.  Gee, what I didn't know
> then    :-)
>
> Your suggestion to seek another technician, of course, is not without merit
> and an excellent direction to take to learn even more about piano
> technology.  Joining the Piano Technicians Guild and associating with
> others would be an even more excellent move.
Sure!  You can always learn from other people.  I still have so much to
learn.  I wish I had to time to learn everything I wanted :)

	Right now I'm trying to figure out why alot of pianists believe a
note played at same dynamic can have different tone quality depends on how
you play it (there might be a reason behind it).  Can this be easily
explained?  Or is this a wives' tale?  Can someone with a very good
understanding of action/mechanism express their opinions?  Are modern
pianos designed so pianists can change the tone quality while playing
(e.g. during a performance) as much as they want without
voicing/regulating?  Is there a way a technician can optimize a piano to
do this?


>
> Sincerely,
>
> Keith A. McGavern
> kam544@ionet.net
> Registered Piano Technician
> Oklahoma Chapter 731
> Piano Technicians Guild
> Oklahoma Baptist University
> Shawnee, Oklahoma, USA
>
>

with regads,
Kuang Wang