Leverage and Dip

[Bill Ballard]

At 11:21 PM +0200 10/4/02, Richard Brekne wrote:
>but if you wanted a 10 mm dip (for whatever reasons), just what range
>there was for choosing a ratio ?

The limits are the same as they've always been. On the high end of 
the ratio it's how light a hammer you're willing to put up with as 
higher ratios become increasingly weak at lifting weight. On the low 
end, it's how  high you can stand to set the sharps at rest above the 
naturals (oh, that's right, we've got a fixed dip) or how high the 
hammer line is before you can't pull the action out from under the 
pinblock.

At 11:21 PM +0200 10/4/02, Richard Brekne wrote:
>If I am not mistaken another aspect of this ratio is the speed of 
>hammer travel
>to key travel as well....

Visualize that as angular motion. An action will give so many degrees 
of swing to the hammer shank for a given number of degrees of dip. 
It's another manifestation of the ratio.

At 11:21 PM +0200 10/4/02, Richard Brekne wrote:
>I tend to agree with David about the distance / weight ratio
>correlation. I just cant see how it can be any other way. The ratio is simply
>the ratio.

I agree, but with a reservation. I just suspect that both measures of 
the ratio have aspects which need cleaning up. In the weight 
measurement of ratio, it's the unpredictable behavior of friction. In 
the linear measurement it's the conversion of the length of lever 
arms (regardless of orientation with "up" and "down") to the angular 
motions of pivoted lines. I can't guarantee that a correlation 
between the two wouldn't be skewed because the continuing error in 
each approach might pull the accuracy of each in different directions.

At 11:21 PM +0200 10/4/02, Richard Brekne wrote:
>Using the balance equation then you can insert this ratio, your 
>known SW's and FWs and
>WBW which you have also physically measured, and solve for BW. If, when you
>begin to actually measure BW you find variances, you know these have 
>to do with
>friction related issues, or small variances governing leverage (i.e. knuckle
>angel and the like). Doing this allows you to further even out the resulting
>touch quite a bit really.

Yes, but the original question was not whether the linear ratio is 
the numerical equivalent to the weight ratio. Rather it was, is there 
someway of determining what the working range of action ratio would 
be if you limited the dip to 10mm. The real answer isn't limited by 
anything in the SBR ratio, but by the case itself (specifically the 
action cavity height).

There might seem to be another answer, but you have to choose between 
cranking the LO button out of the way, and making your observations 
on an action with no escapement, drop or aftertouch. Or simply 
accepting the fact that once the jack hits the LO button, you no 
longer have a direct correltation between the motion on the key and 
the hammer. Which means that you have to abandon the full dip 
(including escapement and aftertouch) as an sample during which to 
observe the effect of action ratio on ones ability to regulate the 
action.

Bill Ballard RPT
NH Chapter, P.T.G.

"I go, two plus like, three is pretty much totally five. Whatever"
     ...........The new math
+++++++++++++++++++++
On the other hand, i could be way out in left field.