June Journal and FW's

[David Love]

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.  Interesting in view of a few comments
recently about the old rocker arm capstans that seem to exhibit better
performance in part by virtue of their "connectedness" to the key.  Wippens
without an assist spring already have a disconnect, as it were.  With an
assist spring that is pulling the wippen up against the drop screw, there is
even greater disconnect.

I am aware of the anecdotal testimonies of those who swear by the recent
craze of monster hammers assisted by highly tensioned wippen springs and
relatively low front weights.  I can report anecdotal information which
argues against this approach by two pianists recently.  Neither report, of
course, constitutes proof.  But I personally think that the best use of
assist springs is to compensate for uneven BW when a perfectly smooth FW
curve is desired.  They can also be used when one prefers the higher SWR's
of the past (for regulation reasons maybe) but doesn't want to be bound to a
super light hammer.  Then the spring can, and should, be used modestly.  A
highly tensioned spring to allow for monster hammers is not, in my opinion,
a desirable set up.  Of course, I don't believe a monster hammer is
desirable anyway.   After hearing several such set-ups recently, I am
totally unconvinced of the tonal benefits.  More tone, yes.  Better tone?
Not in my opinion.

David Love



----- Original Message -----
From: "Richard Brekne" <richard.brekne@grieg.uib.no>
To: "PTG" <pianotech@ptg.org>
Sent: May 28, 2002 1:46 PM
Subject: June Journal and FW's


> Hi folks
>
> With Terrys recent query about Stanwood in mind and after reading Vince
Mrykalo's article entitled Adjusting Whippens Assist Springs in the June
Journal I thought it might be interesting to take a closer look at what
general parameters for FW leads Vince is working with.
>
> He mentions that a BW of around 50 grams is a desirable figure for an
action equipped with assist springs (BW taken with said springs disengaged
of course). I got to thinking what this relates to in FW for various
configurations and so taking Stanwoods balance equation I set BW at 50 gram
, assumed a 9 gram WBW and looked at ratios of 6.0 and 5.7 for SWs of
12,11,10,9, and 8. (course SW = 12 for R = 6 is non applicable) and solved
for FW to compare with Stanwoods table for Maximums
>
> In the case of a ratio of 5.7 the FW values resulting from Vince's 50 gram
BW (assist springs disengaged) were just about 12 grams under the maximums
values for hammers of corresponding SW's for that ratio.
>
> In the case of ratio 6.0 they were right around 15 grams under the
maximums given in Stanwoods table.
>
> for ratio of 6.0 FW's for SW's 11, 10, 9, and 8 were 31, 25,19,13, and 7
grams respectively, and these correspond to key numbers 4,  26,  45, and 60
>
> for 5.7 FW's for SW's 12, 11, 10, 9, and 8 were  27.4,  21.7, 16, 10.3,
and 4.6  grams respectively and correspond to keys 11, 32, 47, 59, and 69
>
> It would seem then that Vince feels that assist springs should do
somewhere around 12 - 15 grams of work.
>
> I am currious as to how that fits in with others who are accustomed to
useing assist springs.
>
> Just musing around a bit tonite... :)
>
> RicB
> Richard Brekne
> RPT NPTF
> Griegakadamiet UiB
>
>