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<DIV><FONT face=Arial size=2>Hello Action Balancing =
Aficionados,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Today I spent a good part of the day =
with Phil
Bondi (who is currently dodging thunderstorms along southbound I-75) =
diagnosing
an 1880s S&S model A 85-note action that plays like a Mack
truck.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Because two heads are better than one, =
and as we
found out, they are likely better by an exponential function, we have at =
least
four times as many unanswered questions as either one of us could have =
come up
with working alone!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We actually did improve one thing right =
off. The
drop screws were turned WAY down to make the pathetically hung crap =
hammers
check - sort of. They were so far down that the rep levers were being =
depressed
at less than half blow. We turned them up and that made quite a =
difference right
away. But still, the action was sluggish.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We measured upweight (UW), downweight
(DW), key ratio (KR), strike weight (SW), wippen weight (WW),
knuckle-to-center distance (KC) and front weight (FW) on =
all the
Cs and C#s. Our objective is to characterize what changes can be made to =
this
action to make for a normal to light touchweight. All results discussed =
herein
are in grams and millimeters.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We also examined magic lines and did =
the
measurements to calculate overall action ration as specified by Ron
Overs.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The action had shanks with =
knuckles 15.7 mm
away from the flange center pin (is that the right distance Phil?). And =
it had
five leads in the bass keys and two in the trebles.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The capstan/wip-heel actually =
intersected the magic
line just after key travel started (not too horribly bad). The =
knuckle/rep-lever
interface started at a full knuckle below the line and ended with the =
line about
half-way across the knuckle at full key depression (pretty =
bad).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>For anyone interested in a painful =
experience, I
will send you my spreadsheet with all the data upon request. For those =
others
more sensible, but still reading this, I will summarize =
below:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>DW ranged from 49 to 63. UW ranged from =
18 to 28,
friction (F) ranged from 12 to 19.5 balance weight (BW) ranged from 34 =
to 45.5,
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What would make the BW so
inconsistent?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>FWs are from at Stanwood's Front Weight =
Ceilings to
about 4g over, KR is .55 for naturals and .53 for sharps, average WW is =
16.5, SW
ranged from heavy-medium in the treble to just into the light zone =
in the
bass, action ratio (R) ranged from 6.7 to 7.5 and averaged =
7.1.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Clearly, the leverage of this action is =
horrible -
too high. We experimented with a 17mm and 16.5mm knuckle-to-centerpin =
distance
knuckles/shanks. They seemed to function very well - you could regulate =
the
notes quite well (we tried the 17mm on one note and the 16.5 on four =
notes).
However, the improved leverage dropped all the DWs to around 41 and all =
the UW
to about 16 or 18g. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Looking for a bit of input here - this =
is too
light, yes? Too light DW and the low UW will produce poor repetition, =
yes?
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Friction on the high friction notes =
dropped to 12
or so and BW dropped to 28 to 30. Calculated R goes from and average of =
7.1 to
6.2 with the 16.5mm knuckles - likely down to about 6.0 with the 17mm
knuckles.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Using the Overs action ratio method (we =
did not do
actual measurements with the 16.5mm knuckles) I estimate that the =
knuckle change
would drop the action ratio down from the original average of 6.4 to
5.9</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>BUT, these keys have a whole bunch of =
lead in them.
We are thinking that, at a minimum, this action needs the knuckles =
placed out at
17mm from the flange center pins to improve leverage. Then, that will =
allow one
or two leads to be removed from each key - remove enough lead to make =
the DWs in
the 50 gram range and the upweights will gain a similar amount - around =
10 grams
or so and end up with about 27g UW.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Ultimately, I think, this piano =
needs a
complete releading (setting gradational FWs) new hammers, shanks, =
knuckles and
flanges and gradational SWs (on some nice SW curve).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Don't know exactly what the piano owner =
will be
willing to do - apparently it is a not-so-well-to-do church. Phil has =
the action
at this point to evaluate it.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Anyone care to comment on our thinking =
here?
Neither one of us are experienced with this balancing methodology enough =
to
decide exactly what to do on our own. And we recognize that maybe we =
need to do
a bunch more measuring also. But we have a start. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We'll be very interested in input.
Thanks.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Terry Farrell</FONT></DIV>
<DIV><FONT face=Arial size=2>(I wonder if Phil managed to drive the =
135 miles
home in the time I took me to write this email?)
:-(</FONT></DIV></BODY></HTML>