Just to elaborate on this a bit more because it think it runs counter to
methods traditionally taught but it is a very effective method in general
and, I think, creates better stability. There are two planes on which the
hammer can move, one is the plane that runs parallel to the strings and the
other is the plane that runs 90 degrees to that. Movement about the first
plane would be purely rotary moving the hammer parallel to the string plane.
Movement about the second plane would not move the pin in the block but only
involves either pushing the hammer down or pulling it up, i.e. flexing or
flag polling the pin. The direction in which the force needs to be applied
in the case mentioned below would be somewhere between those two, let's say
around 45 degrees. So with the hammer in the 12:00 position (and a right
handed tuner) you are pulling the hammer downward and toward you at an angle
of about 45 degrees. Interestingly, that actually adds friction to the
turning of the pin in the block because you are bearing against the top of
the block where the pin enters. That runs counter to traditional methods
that suggest you should actually lift the pin away from that bearing point
to make it easier to move. Of course, that lifting combined with the pin
twisting before it actually moves tends to get the pitch quite a bit sharp
of your target and with a lot of friction that creates problems in settling
the string. By pressing down while turning you counter the twist with a
forward flexing of the pin as I mentioned. As the block gets tighter you
will have to increase the downward pressure in order to counter that
additional twisting of the pin. That adds additional friction against
movement of the pin which is why very tight blocks are the worst case
scenario. Still, with string bearing points that don't render well and
where you want the movement of the pin to exactly coordinate with the
movement of the string through the bearing points, it's the best method.
With blocks where the pin is loose there is much less twisting of the pin
and therefore the amount of downward pressure needed is minimized and you
can use a force much closer to pure rotary motion. Another problem is when
the pins are not uniform in tightness and the angle at which pressure needs
to be applied varies from pin to pin. Similarly, if lowering the pitch you
will be better off with the hammer in the 9:00 - 11:00 position and the
force applied back and up, the degree to which will depend again on the
tightness of the block. As an aside, you can also get the same effect if
you have a ball handle so that you can with the hammer at, say, 3:00 pull
the hammer toward you while turning it down (like turning a door knob) so
that the pin is flexed slightly toward the string. That's a bit harder on
the wrist though.
Interestingly, this method also runs counter to the philosophy of tuning
uprights with the left hand. The idea here is that you are lifting the pin
away from the front of the hole to relieve friction and make it easier to
turn but by doing so you also create much greater string movement through
the bearing points relative to actual tuning pin movement. For the above
method to work on an upright the tuning hammer would be better in a downward
position (below 3:00) whereby the pressure can be applied to the pin in a
similar manner to the grand situation outlined above pulling the hammer down
toward the plate while turning it. Unfortunately, that's not always
practical.
David Love
www.davidlovepianos.com
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Fred
Sturm
Sent: Sunday, October 18, 2009 4:34 PM
To: caut at ptg.org
Subject: Re: [CAUT] Bechstein model B tuning stability
Hi David,
Well stated. Your original post seemed a bit timid:
"A very conscious rotary motion with even a slight forward press"
which kind of sounded like you didn't really mean it about the forward
press. I was just trying to say "right on! press that hammer down with no
apologies!" I agree with you 100%. Including about the worst scenario
(though an extra loose block with lots of friction runs a close second).
Fred
On Oct 18, 2009, at 4:31 PM, David Love wrote:
The basic idea is that you manipulate the pin with counter pressure to the
natural tendency for the pin to twist so that the change in pitch only
reflects actual movement of the pin in the block. At least that's what I
meant in the original post. With the hammer at 12:00 you can press slightly
downward which will move the pin toward the string as you are turning the
pin and it is twisting before it actually moves in the block. With practice
you can learn to feel the amount of downward pressure needed to negate the
pitch change associated with the twisting of the pin. When you release the
downward pressure and also allow the pin to relax with some practice those
two forces will remain net neutral. This allows you to creep up to the
target pitch rather than have to pull it a bit sharp and set it downward as
this is particularly difficult with high friction in the string bearing
segments. The best way to learn this is with an ETD where you can actually
see what's happening while you feel the pin. The amount of pressure needed
to compensate for twisting will change depending on how tight the block is.
The worst possible scenario is severe friction through the string segments
combined with an overly tight block. Usually, Bechstein pianos (at least
older ones) don't suffer from overly tight blocks and the ones that are open
faced minimize the flagpolling effect because of the close proximity of the
hammer pin contact to the block itself.
David Love
www.davidlovepianos.com
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Fred
Sturm
Sent: Sunday, October 18, 2009 9:45 AM
To: caut at ptg.org
Subject: Re: [CAUT] Bechstein model B tuning stability
On Oct 17, 2009, at 3:53 PM, Jeannie Grassi wrote:
Hi Fred, and anyone else,
Can you take your description of downward and upward motion a step further?
I've been hearing conflicting descriptions of this recently in private
communications. What I'm asking is specifically..when the pitch needs to go
up, do you lift up on the end of the tuning lever at the same time there is
a slight rotation to sharpen? And conversely, does one push down and rotate
slightly flat? I've had the opposite described and just want to get a sense
of how most people interpret this deliberate flag-poling motion. I've
always used it the way I've described. Have I been climbing up the wrong
flagpole all these years???? :>)
jeannie
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu
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