Thoughts on Pin Setting

[Robert Scott]

I seem to have unconsciously developed a pin setting technique,
and I would like to hear what you every-day tuners have to say
about it.

First of all, I see major differences between pianos in
how the string gets from the tuning pins to the speaking length.
Some vertical pianos have an almost straight shot from the pin
with nothing to cause friction, while the treble section of
many grands has lots of felt causing lots of friction on
the strings.  In the later case you can move the tuning pin
a lot before anything happens to the pitch, while in the
former case you can sometimes get a pitch change just by
breathing on the tuning hammer.

These differences call for different pin setting techniques.  In
general I find the no-friction situation a little easier to 
deal with because the strings don't move very far when they
settle and its easier to get small changes in pitch.  Of course
I try to make most of my adjustments with pure rotational forces
on the tuning pin and only resort to a bending force when I am 
very close and when just a gentle springing is effective.  If 
gentle springing won't get the pitch where I want it, I go right 
back to pure rotation again.  Most of the time I like to rotate 
the pin to just above the desired pitch and then spring it down.

I have heard one technique described where you test the pin setting
by seeing if you can spring the pitch both up and down an equal
amount from where it is.  On strings with lots of friction I find
that I cannot always spring the pitch both up and down without
resorting to more-than-gentle springing, so I don't generally
do this test.  I suspect that over the long run this technique
may do unacceptable damage to the pin block.

Of course there is also the test blow - a time-honored technique
that is hard on both the ears and the action.  It jars not
only the string you are tuning but also the other two in the
unison.  I don't use test blows either.

What I use is gentle rocking of the tuning hammer in the springing
direction with the pin fitting only loosely in the socket.  This
creates a small controllable jolt in the string that I hope is
equivalent to what a test blow does.  But while a test blow
can only jolt down in pitch, the hammer rocking can jolt both
up and down.  Now I realize that it is possible for a test
blow to leave the pitch higher than before, but that is not as
common an outcome.  If I should spring the pin down too far in pitch
so that it is on the verge of jumping back up, the hammer rocking
test I believe is a more reliable way to test for that condition
than a test blow.  So when I think I have finished tuning a string,
just as I am taking the hammer off the string, I give it a little
rock both up and down.  If the pitch didn't change through that
disturbance, I trust it will not jump a few hours later.  I try to
make it a practice to alway listen to the string one last time after
the hammer is removed in case the act of removing the hammer jolts
the string enough to change pitch.

Whenever I go back and tune a piano that I had tuned previously,
I take notice of the pattern of tuning errors.  If all the pins
had been set perfectly, then I would expect the tuning errors
to be essentially random.  Of course, if the players are always
playing the key of C, then certain strings will detune more than
others just from getting more use.  But the pattern that I find
the more interesting is the pattern in the three strings of a unison.
On some pianos the string with the shortest non-speaking length
is uniformly higher in pitch than its more distant companions.  I
suspect that this is due to my pin setting technique not properly
compensating for the length of the non-speaking segment.  But by
the time I get around to seeing this pattern of tuning errors, I
have forgotten what specific pin setting technique I was using
for that piano, and so I don't learn from my mistakes as fast
as I should.  But I have noticed lately that this bias affecting
the near pins is almost gone.  I think I am becoming aware that
near pins should not be sprung as much as far pins because a little
springing goes a long way on a near pin.  Since I tend to prefer
springing from above in pitch, the effect of over-springing
on near pins would be to leave them wanting to go up in pitch.

I seems that a combination of small amounts of springing and 
using hammer rocking instead of test blows has resulted in
the reasonably good pin setting.

-Robert Scott
 Detroit-Windsor Chapter PTG