Regulating Woes

[Newton Hunt]

Changing the location of the capstan, which you did by moving them
back, will change the touch weight.

Like you I am uncertain why this has occurred but I would check and
see that the main action rail in not warped either when the action is
in the piano and when it is not.  I did have this problem in a grand
action once.

An easy way to check this when the action is in the piano is to
stretch a thread along the edge of the wippens below where is wires
enter and see if it is bowed outward.

If everything checks out then you may consider removing the lead
weights from the backs of the keys.

Determining optimum touch weight for an upright is not so easy because
of the hammer springs.  Any variation in their tension will effect
touch weight.  With that said:

What you are most interested in is not the actual touch weight but the
average of the up and down weights and half the difference.  The
average is the balance weight and half the difference is the
friction.  Like so:

Make sure all hammer springs are properly engaged and in perfect in
performance.

Touch weight is always taken without dampers involved to block down
the sustain pedal.  

Touch weight is defined as the maximum weight a key will lift from
just before before jack involvement and minimum weight required to
depress a key to just before jack involvement all the while jogging
the action to release pin stiction or excess friction.

Down weight is 61 grams and up weight is 15 grams.
	(61+15)/2=38   this is actually an excellent balance weight
	(61-15)/2=23   this is excessive friction so go look for it and fix
it.
	THE BALANCE WEIGHT WILL NOT CHANGE even when the friction does.

BUT you want 36 grams of balance weight so:

Subtract 7 grams (half the friction) from the down weight then place a
small key weight on the key and slide it back and forth until the key
goes down while thumping on the keys.  Mark the location of the
weight, drill a hole in the key and press the weight into place.

New balance weight. Friction should be in the 8 to 15 gram range.  Up
and down weights will vary according to the amount of friction but the
average should be made to be the same you decided you want.  Balance
weight should be at 35 grams for an extreme low and 40 as an extreme
high.

Don't try to deal with 1/2 grams.  Round down to an even number for
subtracting from down and adding to down weight.

Take a few measurements and post them so we can discuss them.  Measure
all Cs and all F#s.

Lots and lots of fun, especially without a full set of graduated
weights.

By the way, if you are using supply house stacked weights with a nut
on top you will need to calibrate those weights.  The smaller weights
van be as much as 30% too heavy.  You will need a fine balance or
digital scale to do this work.

		Newton