action ratios

[Richard Brekne]

David Love wrote:

>
> I'm not sure why it should matter if measurements are being taken
> accurately.  To my understanding of the working of levers is that the
> relationship between distance and force leverages is not idiosyncratic but a
> fundamental principal of mechanics.

This seems an unavoidble conclusion, and I have to agree. Tho I am still open to
someone being able to show that the SWR and the Distance ratio are somehow
significantly independent from each other. But untill such time, I have to
operated on the assumption that they are actually two different ways of
measuring the same thing.

>
> As RB has stated, the fact that at 5.5 ratio, 10 mm dip gives 55 mm of
> hammer travel and that should be plenty when we only need 44.5 doesn't
> adequately take into account what happens after let-off button contact by
> the jack tender.

Point being that the Ratio may not itself be at fault for lack of ability to
regulate correctly with these parameters. And as with all things, tho it may be
able to solve the puzzle in a variety of ways, it might be better to address
that aspect of action functions that are directly at fault in any given problem.



> Though there may be some efficiency of distance lost by the sliding motion
> between friction points (namely capstan-wippen heel) that loss of efficiency
> would not seem to improve the ability of the action to regulate with full
> specs, rather, it would seem to diminish it.

Not quite sure what you are saying here. Seems selfsaid that any loss of action
efficiency, distance or otherwise is going to be detrimental to the system.
Clarification as to what your point is ?

>
> I am still strongly inclined toward setting up actions with great
> consideration given to determining an action ratio that will give proper
> regulation specs.  If there is a desire to use hammers whose weights fall,
> then other solutions, or compromises will have to be considered.  For 99% of
> the actions I do, that seems unnecessary.  For that other 1%, assist springs
> seem to be the most reasonable solution.

Well, I am the first to applaud well thought out personal preference. But I am a
bit wary of definitions as to what  "hammers whose weights fall outside of the
boundaries that allow for a good match of weight to leverage" means. Seems very
important in anycase to be able to provide clear, and concrete rationale that
holds up to scrutiny if one is truly going to cross the border from "what I
personally like" to "what is correct or doable"


>
> David Love
>
> -

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html