[CAUT] F..riction

[David Love]

Equal voicing and ease of escapement I would agree with.  I would add
overall friction levels generally as evidenced by what you mention about
Teflon powder on knuckles and also from the improved feel from a lubrication
of the front rail pins (especially), and also uniform aftertouch along with
a generally accurate and uniform regulation as Fred Strum suggested.  I
would question how one can actually tell about something like inertia.
Playing a block of chords it's easy to see how touchweight (DW) itself can
easily vary by a factor of two in the same voicing if one note is played out
near the end of the key while others are played near the fall board.  Yet
pianists seem to hardly notice that difference at all and routinely adapt to
the position of the finger on the key without apparent incident.  Since
differences in inertia are even less directly perceived than differences in
actual static resistance I would wonder how someone could actually tell the
difference in inertia that results from a FW difference between two notes of
only 10%.  

 

In assessing David Stanwood's comments and from my own experience in setting
up actions both ways (smooth BW or smooth FW), it's clear that some
"floating" is not only always necessary but also goes mostly unnoticed.   My
current basic procedure is to set a smooth SW curve, survey the action's BW
(which also gives a convenient yield of friction readings), calculate what
the actual FW should be to achieve a uniform BW based on that survey and
then establish a trendline using the excel function for that purpose.  That
gives a FW curve that best matches the actual BW target rather than trying
to find an average action ratio which the Stanwood standard procedure calls
for (if I'm not mistaken ) from which you calculate the FW curve.  In my
procedure, irregularities in the measurement of the BW are smoothed over
through the use of the trendline function and a compromise between FW and BW
is established to create the least amount of floating for both curves (each
serves as a check for the other).  If it becomes clear that the sharps and
naturals have two different ratios (which they often do) then you can
establish two different trendline curves and separate the two.  The
differences in inertia between the two lines are masked by the fact that the
sharps pretty much bear no resemblance in performance to the naturals anyway
due to the lever length differences and finger position tendencies.  Given
that pianists adapt to most everything else this one seems like a no
brainer.   Of course, since it would appear that pianist have the uncanny
ability to adapt to the inherent unevenness in a piano action's performance
it would seem like this is overkill.  But why stop now.  

 

David Love

www.davidlovepianos.com

 

From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ed
Foote
Sent: Sunday, December 05, 2010 4:17 AM
To: caut at ptg.org
Subject: Re: [CAUT] F..riction

 

 

 
 I believe evenness to the pianist means equal inertia, equal voicing, and
equal ease of escapement.  The last is 
hardest to judge, but jack position, knuckle condition, friction of the drop
screw and jack tail on their pads, spring 
strength, height of balancier, and aftertouch all play a part. Pianists,
when playing a ppp levels, will be very mindful 
of what the escapement is like under soft play, even if they can't describe
it.  
     A few drops of lacquer solution on the top of a hammer will make that
key feel a lot lighter, a key with 10% more 
FW than its neighbors will also stand out to some, but if there are a couple
of notes that have a "notch" or other hang-up
right at escapement, the pianist will mistrust all of the keyboard, and
complain that the action is uneven. 
I have, numerous times, made a huge difference in the feel of "evenness" by
simply moving all the jacks to the 
proper place when they were far distal of where they should be.
Jack/knuckle friction is another big influence and 
the quick rubbing of some Teflon powder across the knuckles also can do
wonders in this regard. 
Ed Foote
Regards,  
Ed Foote RPT
http://www.uk-piano.org/edfoote/index.htm
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