1

FFF South Eastern Council

Fifth Annual Continuing Education Program For Certified Casting Instructors April 27, 2012 Helen, Georgia

Presented by David Diaz

2

Special Truncated Version for Gordy Hill

Originally presented at Fifth Annual Continuing Education Program For Certified Casting Instructors April 27, 2012 Helen, Georgia

by David Diaz

THE ANATOMY of LOOP THE ANATOMY of LOOP DYNAMICSDYNAMICS

Foundation Series Workshop Number Three

Originator - SOON S. LEE3

4

We are Here

When a field is getting started and you don’t understand it very well , it’s very easy to confuse the essence of what you are doing with the tools that you use.

Hal Abelson, 1986, Opening Lecture in Structure and Interpretation of Computer Programs, Abelson and Sussman, (1986) MIT.

5

Theory of Loop Dynamics is Essential for Instructors

Students frequently can cast and fish, do both well, but remain naïve about casting theory. Some will stay uniformed forever. Instructors, however, have to be informed about theory. Teaching students how to control the formation of the loop is an essential instructors’ skill. For that skill an understanding of loop dynamics, what conditions of line, rod, and hand movement result in the loop is a requirement. Understanding loop dynamics is necessary for fault diagnosis and remedy. Without a useable theory of loop dynamics, the casting instructor is compromised.

6

The Utility of Evidence

To answer the question about how the loop forms requires having evidence.

Gowan’s Superposition of Lovoll’s graphics

Mack Martin’s high speed video.

7

Gowan’s Superposition Of Lovoll’s Graphics

8

Before RSP, unloading occurs and SLP is observable. By RSP, the loop buds and launch has commenced. After RSP the rod tip path is always convex.

9

Thus defined, casting stroke is a compound stroke. (Tailing loop cannot be said to be the result of pure concave tip path either).

Casting stroke with pure SLP does not exist.

10

SLP as Concept

• Taking the easy way out around conflicting ideas about SLP is very productive.

• Doing so has nothing to do with casting. • The cast remains the same. • In this presentation, casting stroke is defined as

ending when the loop launches and is the line is no longer pulled by accelerating tip.

• SLP truly occurs because the convex portion of the rod movement during the stop is excluded.

continued

11

SLP as Concept

• Gowan/Lovoll graphics (next) shows that rod tip path has a convex inclination prior to launch.

• Gravity flattens the convex inclination of the line.• It appears that line path is straighter than rod tip

path.• We are familiar with gravity’s force to depress

back cast height.

12

Gowan’s Superposition Of Lovoll’s Graphics

13

SLP as Concept

• We learn to accelerate rod a certain way to produce

straight upper leg. • Convex inclination of rod tip path compensates for the

effect of gravity on the fly line. • At time of launch, line following rod tip is straight.• Does line follow tip path when the tip launches the loop?• Explain how the line doesn’t follow the rod tip.• Is the axiom about lines and tip now worthless?• Understand contrast between Application for teaching and

Description for understanding.

14

When does loop formation take place?

15

Background on High Speed Video

Five casting instructors sought a reliable answer to the question “When does loop formation take place?”

November 2007 was scheduled for producing evidence.

Loop is formed when the speed of the rod tip falls below that of the line. The line conserves energy better than the rod. The rod unloads quickly; the line dissipates energy more slowly.

16

RSP and Zero Deflection

• Mack Martin designed and constructed the test apparatus,

recorded the data with video cameras, and produced the results.

• Scott Swartz and Gordy Hill were the operators whose casting the cameras recorded.

• Peter Lami kept the perspective orderly by insisting that we all subscribe to fly casting as a slow time-domain activity.

• The Atlanta School of Fly Fishing is owed our gratitude for its generosity in providing the means for the test.

.  

 

17

Predisposition

What we thought was the loop formed and the rod tip reached zero deflection at about the same time.

What the photos show is that the two events take place so closely in time that distinguishing them as a series will probably require time resolution to less than one thousandth of a second.

18

Just before RSP

19

RSP Visible

20

Just after Loop is Launched

21

The Formed Loop Progresses

22

Timeline

• The separation of the line from the decelerating rod tip forms the loop.

• High speed video cameras can stop action for a hundredth of a second.

• Between two consecutive hundredths, the loop buds.

• In another hundredth, the loop blossoms.

 

23

Investigation for the Future

• It remains to be seen what faster cameras can discover to inform us about casting.

• My speculation is that at 1000th of a second, we will not see much change in the loop formation.

• Such additional speed may present a better picture of

what portion of the rod, if any, is actually straight as Rod Straight Position.

• We may find that tip oscillation actually has smaller amplitude and faster frequency.

• Just what significance is derived from those observations becomes material for an as yet unwritten study.

24

As a general caution it is unwise to force the thinking that we use to understand casting on students. Generally it doesn’t help them. That is because the act of casting is not an intellectual activity. In contrast, it is a physical act like swinging a golf club or tennis racket, using a handsaw, pushing the puddle while welding. If the user is too much focused on the components of the action, then he will not swing the rod, club, or racket, the saw or the torch with confidence and smoothly. He will think about the individual movements too much, and like the centipede who becomes overly reflective, he will fall over.

Casting for instructors is both the physical motion and the body of thought that describes it. What I propose is that the second action, entirely intellectual, should be called theory of casting. That is what we are studying.

Pity the Centipede

25

Major Conclusions about Practical and Theoretical

Understanding Anatomy of Loop Dynamics and Casting

Components have parts that are related logically, functionally, and physically.

To be creditable, a theory of casting has to be complete by accounting for all the important parts.

To be useful, a complete theory of casting must include the line motions, rod movements, and caster’s hand and body actions.

Individual parts can be examined but not in isolation.