The Key Leveling products take advantage of the Key Force 1's revolutionary
kinetic "event detection" measurements. The keydip-based product is a bit
cheaper ($60 list), and strives to get the bottom of the keystroke at a constant
distance from the top/at-rest position (i.e. a constant keydip). The aftertouch-
based product also has the machine determine the exact Jack Trip (escapement)
point for each note. That is, much of the technology involved in the FLA product
is also employed in this product! The end result is a prescription for front
punching changes that results in the scientifically determined key bottom - for
every note - being a set distance below the exact jack trip point for that note! In
other words, the prescribed punching changes will result in the actual measured
aftertouch being exactly the specified value, all the way across the keyboard.
This results in extremely accurate aftertouch settings, with minimal labor on
the technician's part! The aftertouch-based key leveling product still has a very
reasonable list price of $85.
As mentioned, every time a note has its bottom/dip location kinetically
determined by the Key Force 1, an entire force versus punching deformation
curve is acquired. While these will likely not be provided as output, two sample
curves from measurements on adjacent notes of a real piano are shown below:
Note that the blue square and orange diamond represent the initial and final
stiffnesses, respectively. The top of the green rectangle gives the average, or
overall, stiffness value. Depending upon the shape of the deformation curve, the
average stiffness will not always be exactly halfway between the two local stiffness
values. In fact, the amount and direction that the top of the rectangle deviates
from the midpoint between the two points is an immediate indication of that
curve's shape and character.
The key leveling measurements by the Key Force 1
thus involve: finding the
key's exact as-is "bottom", then finding the key's at-rest position via a short series
of quick, repetitive collisions between the KF1's finger and the at-rest key. Once
all notes have been autonomously measured in this manner, the raw data is auto-
matically placed into an analysis spreadsheet, with one or two clicks. This sheet
allows you to enter any combination of desired keydip (or aftertouch, as the case
may be) and key height. All required punching additions or removals are immed-
iately calculated and displayed. The rest and depressed locations are also
graphed, right along with your desired key height and dip/aftertouch. An example
such a macrograph - for the case of keydip-based leveling - is as follows. This
piano had been leveled and dipped with conventional methods, but the technician
hadn't noticed the significant drift - starting at note 39 - until he saw this Key Force 1
plot. There was some sort of a
bedding problem with the action frame on this piano.
It should be stressed that both key leveling products utilize the world's most
scientific and nondubious means of determining the "bottom" of each keystroke.
As an added indicator of the technology and science involved, each key leveling
product also gives you exact, unprecedented information on the stiffness
condition of each front punching, for all 88 notes! As part of using kinetic key
leveling to find the actual bottom, an entire Force vs. Punching Deformation
curve is obtained for each note. This is the curve that the software uses to auto-
matically determine the exact key bottom. But it's also the curve that gives the
aforementioned punching stiffness values. With these products, you receive
three separate stiffness values for each note - in a very graphical, intuitive format.
The three are the "initial", "final" and "overall" punching stiffness values. The
combination of these three values gives you, the technician, immediate knowledge
of not only the stiffness, but how that stiffness varies with increased deformation.
Strange behavior is thus immediately and graphically discernible for each and
every note! Such output from an actual piano action is shown just below. Due to
the length of the graph, it is cut off on the right after note 57.