Lost Motion and Touchweight

[Richard Brekne]

Hey Patrick.

There are several reasons why elimination of lost motion in an upright can cause
the player to feel an increase in touch weight. Part of it is psychological, and
part of it is real. Especially if there was lots of lost motion.

If there is say 2-3 mm of lost motion then the key is more or less weightless
for that first part of the stroke. The initial movement downwards gains momentum
and when the action is engaged inertia of the key movement relieves some of the
sensation of weight the finger feels. This is an old trick really for making an
upright action "feel" lighter, (tho I am not a fan of this trick) Lost motion
also means the damper is engaged at a later moment in the key stroke, so when
you eliminate lost motion you in effect engage the damper earlier. This can
easily increase the sensation of weight.

I never make an adjustment in someones piano without first convering with the
customer.... exactly because of this kind of thing. Makes no difference how much
I "know" the action is out of wack...

In addition, I have run into "custom regulations"  several times over the years
and you usually have to use some time to figure out just whats been done and why
before making any single adjustment like eliminating lost motion.

Cheers

RicB

Patrick C Poulson wrote:

> Hello all: I got a call today from a customer whose Knabe console I serviced
> at the end of July. She complained that something I did has made the piano
> have a very heavy touch, not only to her but to her husband, and she wants
> it put back to its former condition. I looked up my record on the piano and
> saw that aside from tuning it I adjusted the lost motion.  I have never had
> anyone complain about the piano having a heavy touch after having the lost
> motion adjusted. My experience has been that the piano plays better, and
> previous tuners may have been ignoring the need for the lost motion to be
> taken up.  She says that she has had it maintained by well respected
> technicians where ever she has lived, the last one being the technician for
> a Steinway dealer. She has moved out of his service area, which is why she
> called me.  I am at loss to figure out how taking up the lost motion could
> make a piano have an uncomfortable heavy touch.  My guess is that she had
> grown accustomed to playing an out of adjustment action, and that a properly
> adjusted action with a firm touch feels "heavy" to her.  I have an
> appointment tomorrow morning to check the piano over and do what is
> appropriate to satisfy her, but I'm scratching my head as to how to put the
> piano back out of adjustment in order to satisfy her. Has anyone run into a
> similiar situation?  My notes do not mention any sluggishness or tightness
> in the flanges, and she says she noticed this change in the touch
> immediately.
> Thanks, Patrick Poulson, RPT




--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html