June Journal and FW's

[David Love]

Interesting to hear the opposition to the Stanwood camp on assist springs.
I tend to agree.  I will say that I don't use assist springs as part of an
action design.  However, I can see how one might use them on an existing
action with weight problems when you don't want to change the hammers or
existing geometry, or to achieve an unusual result.  For example, I have a
customer who has problems with her hands.  She wanted a balance weight down
around 26 grams.  Definitely non standard.  The piano is a S&S D with
Steinway hammers.  The options were to turn the hammers into q-tips, move
the capstan and end up with 1/2" key dip, fill the keys with lead, or add an
assist spring.  I opted for the assist spring.  Though this is an extreme
example, similar situations can arise in which that solution may be the best
alternative.  Under ordinary circumstances, however, I have had only
compliments on evenness since I began to employ the BW method of doing a
weigh-off.  Minor variations in the FW seem largely imperceptible even to
the most sensitive pianists.

The other issue is one of design versus execution.  It is one thing if a
piano has a bad design that needs improving.  It is another if the piano has
a good design which is just poorly executed.   Steinway pianos fall
frequently into the later category.  I think it is a good design that runs
into problems with poor execution, namely, inconsistent capstan placement
and mismatched hammer weights for varying action ratios.  I think that
before one starts monkeying with changing the characteristics of a
successful design, one should be sure that the outcome is in fact what the
customer wants.  This can be said about other things besides action design,
for example, scaling.  Moreover, I think the customer should be made aware
if a design change deviates considerably from standard for that manufacturer
and you should have the customer sign that they agree to such a change.  I
have recently been called upon to undo two such changes (original work not
performed by me) because the result was not what the customer expected, nor
liked.

Immersing ourselves in design technology it is easy to lose sight of what
attracted a customer to a piano to begin with, and to start to make
wholesale changes without regard to their tastes and desires.  Not that we
shouldn't be asking questions and looking for improvement.  But we can also
become arrogant and overconfident in new found knowledge and it can get us
into trouble.

David Love


----- Original Message -----
From: "Richard Brekne" <richard.brekne@grieg.uib.no>
To: "PTG" <pianotech@ptg.org>
Sent: May 29, 2002 11:34 AM
Subject: Re: June Journal and FW's


>
> David Love wrote:
>
> >I don't like to use assist springs for more than about 9 - 10 grams of
BW,
> >or the effective weight of the wippen.  I don't like the wippen to be
> >lifted
> >too much.  Just floating is as far as I like to go.  At 15 grams I find
> >that
> >I don't like the feel of the action.
>
>
> Nice musing as usual David. :)
>
> The reason I ask is that I see a lot of variance in this assist spring
issue, and for that matter whether or not the spring should be used at all.
And all this goes really back to the hammer mass / FW amounts discussion.
Jan Grossbach is one of Klaus Fenner's buddies. Together they have just
written what is probably to date the most complete piano designers textbook.
Jan is an opponent of David Stanwoods ideas, and largely bases this on a
general opposition to assist springs. He takes the position (as I understand
it) that says whippen assist springs should only do enough work to even out
Downweight variations, and that these should be so accurate to begin with
that assist springs are really superfluous. This is in principal not too
awfully distant from your own observations about the difference between
Stannwoods inertia priority frontweighting and the older BW priority
weighting. Course you take the position that whippen assist springs could
also be used to lower BW somewha!
> t and Jan G doesnt go along with that at all.
>
> Course he is not alone. Steinway Hamburg, Schimmel, and a bunch of the
others over here dont employ the whippen spring. Recently I took apart a
Schimmel 6 foot Grand and found hammer SW's ranging from well over 14 grams
to just about 8. I found over 65 grams of lead in a few keys. Now THAT's
what I call massive amounts. In anycase we see that the field of play here
is quite large indeed. Ranging from heaviest hammers of 14 + grams  to 10 or
below (McMorrow suggests less I believe), heaviest FW's ranging from nearly
70 grams to perhaps as little as 15 grams (perhaps less ?) and assist
springs doing 20 (+?) grams of lifiting  down to "they should not be used at
all".
>
> I suppose this is one of the reasons my own choice is for what appears to
be in the middle of all that for the average mean piano, tho I end up a tad
on the heavy side as I am not a fan of whippen assist springs. I just think
thats one more adjustment / weight contribution that can go bad or be mucked
up by an inexperienced hand and that it is simply not neccessary in most
cases to achieve very good and appropriate results.
>
> I like to give manufacturers at least some benifit of the doubt, and
wonder then why they choose to seemingly ignore Stanwoods thoughts, or
McMorrows for that matter. They still use what equates to rather uneven SW
curves (notable exception is Steinway Hamburg over here) and the old style
of Front Weighting. Some dont even go so far as to start off with any kind
of pattern leading. At best this results in an even static Downweight.  So
WHAT basis is there really that this is to be prefered then other priorities
looked at by McMorrow, and then Stanwood, and no doubt others who have not
formalized their thoughts for the rest of us to read about yet ? And for
that matter what real basis do any of us others have (other then what
amounts to personal tastes and opinions) for what we choose ?  As far as I
know Stanwood, and to some degree, tho on a different tangent, our Russian
friend Alexander Galembo are the only folks too formally look into the
matter and their results are quite !
> different.
>
>
>
>
> Richard Brekne
> RPT NPTF
> Griegakadamiet UiB
>
>