June Journal and FW's

[David Love]

----- Original Message -----
From: "Bill Ballard" <yardbird@pop.vermontel.net>
To: <pianotech@ptg.org>
Sent: May 30, 2002 8:27 AM
Subject: Re: June Journal and FW's


> If what you're saying is that when Steinway actions happen to work
> out because of a happy combination of SW and KR, that constitutes >a well
designed action, then I'll respectfully disagree. It made be a
> well designed action, but the engineer(s) who fail to notice that the
> design as issued by R&D dept, is not being consistently installed
> haven't done their job well enough

Not having seen the initial design specs it's hard to know who to blame.  I
gather that it's a complicated problem getting many departments to work
together to get things in the same place every time and to do the necessary
retooling/retraining to insure that everybody's on the same page.  If you
don't index the plate, what chance do you have for any consistency.  I
suppose you could blame the design engineer for that.  Unfortunately there
is often a gap between design and execution and design engineers don't
always get involved in the production.

> >In another case, a classic "new hammers old geometry >arrangement" had
the >problem "fixed" by a set of assist springs.  >Here a relatively heavy
hammer (NY Steinway) on an original >dimension knuckle (15.5?) created an
undue
>amount of friction in the action which, of course, was unaffected by the
>addition of assist springs.  Although the balance weight was reduced >by
virtue of adding the springs, a 38 BW still resulted in a 56 DW > >and .  I
can't really blame the assist springs for high friction.


> Why would one blame the WAS for the high friction? The WAS's >upward
pressure through the rep lever onto the knuckle might be a >measurable
quantity, but would it be any more than the upward >pressure supplied  by
the FWs doing the similar counterbalancing? >The source for the  friction is
in the combination of the high SWs and >the short knuckle  mounting
distance. The friction applies itself at the
> knuckle/replever, and at the capstan/heel.


Yes, I totally agree with that.  As I said, I wasn't blaming the assist
spring for high friction.  I was, in this case, criticizing the use of the
assist spring to fix a problem that lay elsewhere.

For me, the happy medium with the assist spring will probably be to use it
purely as a method of mitigating uneven BW due to manufacturing
irregularities and allow for smooth FW's and inertia.  That means using the
WAS for very minimal adjustments of the BW, under 5 grams.  That would tend
to put HW's in the medium range in order to keep leading well under maximums
without compromising the SBR (5.75 is my ideal).  I will also be glad when
Renner starts producing their own WAS wippen, which, I understand, is coming
soon.  I am not that thrilled by the Tokiwa parts.


++++Back in my home town we have a chicken festival and an egg festival.
Problem is, I can never remember which comes first.++++

David Love