Action Analyses (was Capstan Relocation)

[Clark]

Ron Nossaman wrote:

> if the jack was
> backstopped by a relatively light, short range spring instead of a
> relatively firm felt, wouldn't the jack ride the knuckle through the entire
> range of movement, deflecting and rolling rather than sliding, and produce
> very nearly zero friction until letoff? 

It looks like Darrell Fandrich's grand action does this and ties the
jack to the shank with the torsion spring, like to Diane Hofstetter's
Fischer action in replacing the repetition lever. Another option is to
incorporate a positive stop on the shank, per Broadwood and Steinway, or
it could be on the part against which the jack bears, like the butt in
single actions (hey, did Kawai really reinvent the single grand action?
weird) or the intermediary lever such as Brown's later models,
Gildemeester & Kroeger's and sort of in Alexander's.

Richard Moody suggested reassessing the old window bearing felt,
typically which is softer and may produce the same result. Also it has
the effect of reducing the inertial mass of the jack potentially to
speed its reseating (and three less holes means faster production).


Clark