Upright Touch weight

[Isaac OLEG]

Hello,

I am feeling that there is not really something we could name Down
Weight in uprights.

The hammer weight does not play a real role, most often the weight in
uprights is more a springy resistance, exacerbated by the numerous
springs of the action (hammer springs, repetition, then damper
springs).
Because of the springs compression, the real weight (very low) is not
felt much.
The pressure necessary to move the parts is acting only on the very
beginning of the stroke.

Hopefully, when we attain a good balance in upright regulation, we can
obtain a good distribution of the inertia and resistance of the
action, that is more an equilibrium game to me that the grand action
weighting process.

Best thing I've find at this time, beside staying sure that the hammer
"drops" and that the jack reengages, is to obtain the most clear and
controllable sound, generally because the hammer obtain the best
velocity with the regulation adopted.

And it may be with the help of more play under the knuckles than
admitted generally, if that helps to gain ease and energy in the
action.

I am less in favor of the very strong attack obtained with almost no
play, while it is a working option on the smaller pianos.

Stanwood methods could be applied to determine friction and how much
pressure in grams is necessary to action the key.

You always can use weight to regulate springs, but your own hand/arm
weight may well be enough precise for that job too.


BTW, I've seen an old Schimmel spinet with catchers on very long
hammers that was working as a charm (with a key level regulating screw
too)

Regards.

Isaac OLEG

Pianomaniac from there






> -----Message d'origine-----
> De : pianotech-bounces@ptg.org
> [mailto:pianotech-bounces@ptg.org]De la
> part de Farrell
> Envoyé : vendredi 20 septembre 2002 18:05
> À : pianotech@ptg.org
> Objet : Upright Touchweight
>
>
> Two questions regarding upright touchweight.
>
> First is the damper spring influence on touchweight. Let's
> say, with dampers lifted off strings and spoons not ever
> touching damper lever, touchweight is right on target -
> let's say 50 grams DW across the keyboard and 30 grams UW.
> Then we release the damper pedal so that dampers are
> engaging in their normal manner. Assuming some normal
> amount of friction associated with the damper flange and
> spoon riding on the damper action cloth (perhaps about 5
> grams?), is there a range of resistance (or added DW) that
> one can expect to encounter in a reasonably well designed
> and operating damper system? Stated another way, how much
> additional DW should I expect a well functioning damper to
> add to touchweight?
>
> Second is key weighting. Is there any Stanwoodesque method
> at arriving at a calculated target balance weight for an
> upright key? I can only assume that manufacturers assemble
> the piano completely and then manually weight off the keys
> by tradional methods.
>
> Thanks
>
> Terry Farrell
>
>
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