Front Weight--measurements

[Jon Page]

At 06:28 PM 07/17/2000 -0700, you wrote:
<snip>
>Gotta admit.. this stuff is really fascinating. From what I can tell from
>the stuff included in the Stanwood kit, The Whippen Weight Ratio and the
>resulting Whippen Balance Weight look ok. Also the Strike Weight looks
>reasonable. The Balance weight is way of the scale due to really high up and
>down weights. The Front Weight seems really really low. Increasing FW by 20
>to 25 grams would bring Balance Weight down to acceptable levels but that
>alone will not change the Strike Rate Ratio by much which seems a bit on the
>high side here.
>
>
>David, if you are reading this I would really appreciate your comments. As
>for the others reading this thread...thanks muchly for the input and your
>responses to this would also be greatly appreciated. I can see I am going to
>need some time and feedback to make the most of this fine tool. Thanks for
>the advice so far.. keep it coming...grin.
>
>Richard Brekne
>RPT,  NPTF
>Bergen, Norway

Richard,
The best way to understand this is to become a Stanwood installer.
This "stuff" is corrected with relative ease with the specifications which
David supplies.

The friction is extremely low except for notes 64, 77.
What method do you use to acquire Up Weight and Down Weight?

While you had the hammers off the rail you should have graduated the Strike 
Weight.
That's always good for starters.

Roger made a good point for the capstan position. The contact point
between the wippen cushion and the capstan should fall on a line drawn
between the balance rail hole and the wippen center pin when the key is
depressed holding the hammer at half blow.

I would like to take it one step further. Start with proper hammer height, 
hammer blow, key height, dip,
action spread, letoff and drop (all that stuff).  Then with the key fully 
depressed, notice the juxtaposition
of the jack to the knuckle. If it is buried into the stop felt at the end 
of the rep lever, the capstan is too far
back on the keystick. If the jack is situated just in front of the knuckle, 
this is ideal for repetition.
If it is causing the hammer to almost bobble, then the capstan is too far 
forwards on the keystick.
the trick is to find the KR which develops the ideal jack follow-thru by 
driving the wippen through the
optimum distance.

On the last few actions I have found that this required attention. The line 
at half-blow was
already on the contact point, I started looking at the angle at which the 
capstan was installed.
Setting the hammer at half-blow and running the line; I marked the 
intersection on the wippen
cushion. Then removed the wippen and drew a line through the mark 
perpendicular to the
cushion and re-installed. Reset the hammer at half-blow and extended the 
line onto the key side.
The capstan at this angle resulted in a perfect regulation. The angle 
formed between the
wippen and key at rest was equal and opposite to the angle formed at let-off.

The action which had the capstan buried into the felt now had the jack just 
in front of the knuckle.
The capstan was 90 degrees to the keystick, changed to 3 degrees (angled 
drill hole from slightly
forwards - same contact point); the action which did not have sufficient 
jack clearance had the
same result by reducing the capstan angle from 16 degrees to about 3 
degrees.  This is not to
conclude that 3 degrees is the ideal angle but that this has been the case 
with the last few actions.

I am at this point in the regulation process on another action and will 
report later today the results
of any steps taken.

Have fun,

Jon Page,   piano technician
Harwich Port, Cape Cod, Mass.
mailto:jonpage@mediaone.net
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