[pianotech] Shank questions

[David Love]

The answer of what one would expect is complicated.  In short, in that
section of the piano I would expect not much tonal difference at lower
levels of playing.  The stiffer shank would mean somewhat less ability to
feel of the hammer at lower levels of acceleration but at higher levels I
would expect greater power and more consistent tone given what might appear
to be equal levels of acceleration.  The stiffer shank with the somewhat
heavier hammer in that section would tend to minimize action saturation as a
result of the shank flexing.  You would be able to achieve a higher level of
output or the forte wouldn't top out prematurely.  Since the shank not only
flexes downward but also twists some then the stiffer shank would also have
the benefit of keeping the hammer more consistently square to the strings
through impact.  That would produce greater consistency at higher dynamic
levels and overall more power.  

Generally speaking the stiffness of the shank should work in concert with
the hammer weight in order to balance feel and control.  More flexible
shanks will transmit the feel of the hammer head more easily but sacrifice
control.  Stiffer shanks will give more control but there will be a loss of
feel.  That loss of feel will be most evident in the upper end of the piano
if the stiffness of the shank is too great for the weight of the hammerhead.
In the lower part of the piano, the heavier hammerhead will balance the
increased stiffness to still transmit feel, will help with loss of energy
through excessive flexing and produce greater control by modulating more
consistently the release point of the flexed shank combined with reduced
torque or twisting.  

Interestingly, the early trends with hammer shanks was a graduated thickness
all the way from the bass to the treble.  Some of the early shanks were
squared off and quite substantial near the flange and then tapered to a
rounded profile of some diameter (often 3/16") nearer the hammer head.  The
length of the rounded part of was quite short in the bass and became
increasingly longer in the treble.  That current trend has the shanks either
completely uniform through, usually, about note 55 where they are either
gradually tapered in two steps, or through about note 72 where they are
tapered in one step through the rest of the piano.  Some shank suppliers are
now tapering entire sets in the manner of the upper treble which I don't
care for.  While that can be a benefit in terms of feel, especially at lower
dynamic levels I can't see how that could be a good thing in the lower part
of the piano at higher levels of play or further once the weight of the
hammer set overall gets to any significantly higher level as you often see
in concert grands or larger performance pianos.   


David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of John Delacour
Sent: Tuesday, May 24, 2011 7:53 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Shank questions

At 07:01 -0700 24/05/2011, David Love wrote:


>What section of the piano did you conduct the experiment in: bass,
midrange,
>treble?

A# 26, 6 plain wire notes above the break.