CAUT

Greetings,

I have heard it said by several credible sources that the stronger the repetition spring is ("butterfly" style), the quicker the key return will be. This notion has been used to support increasing the center pin friction of hammer and repetition lever centers that are too loose (more friction to work against = greater spring tension required to overcome said friction). I have subscribed to this notion myself, but not until now has anyone challenged it.

Gonna do my best "Ron Nossaman" impression here: Has anyone either conducted an experiment or heard of one to "either confirm or dis-confirm" this notion?

And on a related note, if the front of the key lifts more weight, does that necessarily mean that it comes up faster?

Thanks,

Alan

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Alan Eder, RPT
Herb Alpert School of Music
California Institute of the Arts
Valencia, CA
661.904.6483
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The basic is that, during the return, the are two parts of the rep which need to get back in place to be able to play the next note. It's a miniature race but, for the next note to get played, the jack has to win. Lowering the center pinning in the shank and the balancier works against that. Even worse. loose parts here make for "fly-away hammers" during the pianist's down stroke: very difficult for the pianist to control.

Do we want to jack to win that race? Low pinning friction at the jack and high friction at the shank and balancier does that. An added benefit here is that the butterfly spring will have to be stronger, in order for the rise from check used for the adjustment to be visible.

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William Ballard RPT
WBPS
Saxtons River VT
802-869-3161

"Our lives contain a thousand springs
and dies if one be gone
Strange that a harp of a thousand strings
should keep in tune so long."
...........Dr. Watts, "The Continental Harmony,1774
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