Theoretical Action Weight Question (kinda long)

[Farrell]

My question revolves around re-weighing a keyboard.

I have been trying to find a good resource for a description of an effective
methodology for weighing-off a keyboard. I have had little luck. My
assumption is that established procedures follow: Get hammers in good shape
(new or filed, etc.), get all friction components to acceptable levels
(within a few grams of each other), and regulate the action. Then, with the
action in place, put your desired gram down weight on the end of the key and
balance the key with various desirable combinations of key leads. Re-test
the down weight and up weight to be sure you are where you want to be,
readjusting the key leads as required.

It seems to me that you would always have a great potential for a several
gram error that way because of friction variations from note to note (which
is going to be continually changing), and because of the one or two gram
error inherent in measuring down weight and up weight.

Is it possible that the following method would yield more consistent
results?

1) Be sure that excess friction in key bushings is eliminated.

2) Identify several notes at both ends of the keyboard that perform ideally
(your call) with regard to friction (ideally #1 and #88 - and be sure they
are properly regulated) by precisely measuring up and down weights.

3) Record the measured up and down weights of these notes (realizing that
they may be higher or lower than that desired).

4) Remove action stack.

5) Place round tube (plastic or metal pipe about 1" tall) over capstan of
one of the ideal notes.

6) Set weights upon capstan (actually on tube) such that they exactly
balance the same down weight (measured in step 3) of that note. Do the same
procedure for the other notes measured in step 3. These should be
consistent, varying only with varying hammer weight.

7) We have now accurately replaced the action weight plus an ideal friction
component with the weights resting upon the capstan. After doing this at
both ends of the keyboard, a simple mathematical calculation will provide
the idealized action weights (at the capstan) for all 88 keys (you will need
to do this process twice - once for the naturals and once for the sharps
because of differing center rail pin locations causing different key
leverage components).

8) Remove old key leads and properly plug.

9) Place the idealized action weights on one capstan at a time, place your
desired down weight at the end of the key, and balance with appropriately
placed lead key weights (each key lead should be the weight of your intended
key leads less the weight of the wood plug that will be removed during key
lead installation). Mark key lead locations.

9) Install new key leads.

Now you have a set of keys that are weighted independently of any variations
in action friction from note to note (which will always be changing anyway)
and the small inaccuracy associated with measuring down weight (it seems to
me that is always an opinion call within perhaps two grams - if you balance
a nearly frictionless key, you can repeatedly do that to within one gram).

Am I like way out in right field or do these thoughts seem to have any
merit? Can anyone recommend a resource for an excellent methodology?

Terry (can't blame a guy for thinkin') Farrell
Piano Tuning & Service
Tampa, Florida
mfarrel2@tampabay.rr.com