Question

Walter & Group...

Question from Jerry Puckett:

Gordy:

 

Is "translation" the linear movement of the casting stroke that:

 

1-acclerates the fly line and       NOT MUCH

 

2-removes slack    SOMETIMES

 

And "rotation" the angular change (casting arc) that loads the rod!    YES.

 

The "casting stroke" is the sum total of translation and rotation?  Not concerned with when the stroke begins and ends!  USUALLY.

 

Thanks, Jerry Puckett

 

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jerry...

My "short answers" in your text, above. in RED ITALIC CAPS.     Details, below:-

 

Pure translation is linear movement of the rod with no rotation added.

 

Pure rotation is angular movement of the rod with no linear movement added.

 

 Pure translation without any rotation is used by a few competition distance casters at the start of their forward cast.  (ie. Rick Hartman's distance cast.)   Some other distance competition casters don't use it (example = Steve Rajeff).

This pure translation at the start of the distance cast can:

1.)  Overcome the inertia of the fly line.    2.)  Allow for change of hand position for the rotational movement to follow.

3.) Help take up unwanted slack.

 

Pure rotation with no linear movement is rare.  One example is the very short accuracy cast made by some casters.

 

In the real world of fly casting, almost all casts are made with a combination of translation (linear movement) mixed with rotation .  Commonly, the caster starts the cast with more translation than rotation, then as the cast progresses, rotation dominates.

VERY LITTLE ACCELERATION OF THE ROD TIP CAN OCCUR WITH PURE TRANSLATION SINCE THE ROD TIP CAN MOVE NO FASTER THAN THE HAND.   VERY LITTLE ROD LOAD CAN RESULT.

BY FAR MOST OF THE ACCELERATION OF THE ROD TIP OCCURS AS A RESULT OF ROTATION.  THIS IS DUE TO THE MAGNIFICATION OF THE DISTANCE TRAVELED BY THE HAND BY THE LENGTH OF THE LEVER ARM (THE ROD) IN THE SAME TIME INTERVAL.  IT IS THIS ACCELERATION WHICH RESULTS IN LOADING (BENDING) THE ROD.

I look at the casting stroke as the movement of the fly rod sufficient to result in loop formation.  This can be pure rotation, but is usually a combination of translation (linear movement) and rotation.

Around the World, argument exists as to whether or not to include initial pure translation in the casting stroke.  This may remain forever a matter of opinion !  Interminable debates continue yielding a new definition for "infinity".

 

                                                          INFINITY

                                        Dogs have fleas and cats have fleas

                                           And fleas have fleas that bite-em

                                        The larger fleas have smaller fleas

                                                    And so ad infinitum !

                                         - Ogden Nash-

 

(Sometimes that reminds me of the "BIG ENDIANS" and the "LITTLE ENDIANS" of Gulliver's Travels.  The never ending debate between those who were convinced that a boiled egg should be opened at the big end and those who insisted the egg should be opened at the little end ! )

Gordy