Loop size / Loop shape / Casting mechanics, cont's

Walter & Group...

Bruce Richards places his comments in Soon Lee's text on loop size.  Bruce's comments are prefaced by ***** and I converted them to italics .   A couple of additional comments by me in text in blue italics.    Gordy :

Hi Gordy,
 
I am always the odd man out when there is a discussion on the role of straight line path on loop size.
 
I am of the opinion that straight line path of the rod tip only determines a straight fly leg. It is essential to throwing a loop with parallel legs but it does not determine loop size. Straight line path is just as essential to throwing a wide loop with parallel legs. Just this latter observation alone will refute the statement that straight line path is the raison d'etre for tight loops.

 

****Soon is right, of course, straight tip path during the casting stroke only determines that the top leg will be straight. However, that is necessary to make a tight loop. Also, a tight, but tailing, loop was made with a tip path that wasn't quite straight. But that thing to remember is that our tip path is never quite straight, at least I've never seen it. But the closer to straight it is, the tighter the loop in most cases.

 

The bottom leg position is determined by what happens after RSP, mostly. It is very possible to make a loop with a very straight top leg (SLP during CS), but then drop the tip which would also drop the bottom leg opening the loop.

SLP during the casting stroke is needed to make a straight top leg, which is necessary to throw a tight loop, but does not automatically mean the loop will be tight.  BR

 
Loop size is the result of multiple factors: 
1) extent of rod bend at the "stop", a product of rod stiffness and caster performance;

 

 

***true, more rod bend means more counterflex, which will open the loop, at least initially.   BR

 

2) profile of the rod bend at the stop (whether rod counterflex is largely directed forwards, or counterflex is directed more downwards);

 

 

****Yes, but if the counterflex is directed more downward it is likely that the tip path was also curving down at RSP. BR

 

 

3) the degree of abruptness of the stop (Lefty's speed up to a stop....);

 

 

*****Yes, the slower the "stop" the more the rod will continue to rotate during the stop, which will drop the bottom leg.  BR

 

( I think that is what Lefty meant when he stated that the loop size depended upon the distance that you speed-up-and-stop.  Gordy )

 

4) purposeful manipulation of the rod tip by the caster at the stop: stiffening up the rod shaft by thrusting along the axis of the rod (Lefty's stab) moves rod bend distally, shortening effective rod length with consequent reduced rod bend....Bruce Richards points out that a shorter rod casts tighter loops. Alternately purposeful, exaggerated rod rotation at the stop widens loop size.

 

 

****Also true.

If some are tying loop size strictly to tip path they will only be partly right. To thow a good tight loop it is necessary to have a straight top leg, which comes from a straight tip path during CS, but there is more to a tight loop than top leg.

 

Bruce

 
Loop shape has its own causative factors, but that is another story.

 

We will devote a whole range of messages to the determining factors for loop shape.    Gordy
 
Soon S. Lee.
 
 

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                                                                    LOOP SHAPE

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From Jim Penrod :

Hi Gordy,

   Reading through all of this brings some images and thoughts to mind. At a symposium at Mt. Home a few years back we had the privilege of doing a tip casting class with Al Kyte (what a delightful instructor). Such a simple move   -stick the rod up vertically and pull one's elbow down. There was ever so slight of a rotation with the wrist and a beautiful tight loop. Add some line and on the downward move bend the wrist slightly more and the cast was longer but again with a nice tight loop. That says that translation does not have to be in an horizontal path.

 So is this upward movement just repositioning the line or is it part of the  casting stroke? Is there really an answer to that? You and I tried making casts with no translation move-almost impossible as we discovered, which makes me wonder how does one define stroke.

   Perhaps more mundane is my concern about "stagnation" or even decline (ageing aside). One cannot afford the luxury of being satisfied as to where he/she has gotten.

I can make tight loops but how do I make needle points and how do I try to train myself to do that? It has to involve an ever so slight upward thrust at the end of rotation, at least in my minds eye, and if not what is it? It certainly would be helpful when trying  to cast through David Lambert's rectangles. I am all ears and hope others are also. And of course I would like to be able to throw arrow points on the back casts as well as the  forward casts. I drool everytime I see someone cast an arrow point instead of a rounded loop.

Jim

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Jim...  I'll be brief with my answer, since I can only sometimes achieve that needle shaped loop.

Steve Rajeff and I were fishing together a few years ago when I asked him to try to show me how to do that.  He taught me to make that upward-forward thrust as close to RSP as possible.  I never got to the point of being able to make it regularly as he does.  Neither of us could be sure whether that thrust was being made just prior to RSP or during the start of counterflex.

I must say, that there are real needle pointed loops and apparent ones.  Steve makes real ones.  Some others make ones which appear to be that shape when viewed from the side as they cast in an off-horizontal casting plane.... then when I stood to the rear, the loop was not really pointed when viewed from that position.

Let's hear from some of you who have perfected this needle sharp loop or have studied the casts of those who have.

Gordy

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                                                              CASTING MECHANICS, CONT'D

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From Lou Bruno :

Gordy,

I want to thank Tony for his response. I remember the email to the link, at the time I wasn?t concerned with damping, just tension, oscillation, counterflex and rebound. I can focus on certain topics and overlook others?our continuing discussion helped in clarifying the topic of ?vibration.?

 

Thanks

Lou

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From Bill Keister :

Gordy,

 

Finally found the Glossary.  Seems to be some definitions missing.  I have attached some definitions as they appear to me at this time.  I really see the stroke as an over arching term encompassing translation and rotation.  This is a very mechanical view of the "cast".  I am curious to know how these three things can be related without what I would view as an artificial delineation.  Translation and rotation are in constant interplay while the rod is being powered to move the fly line.

 

I like to think about the motions and forces on the rod and the line independant of the biological organism that actuates the system.  A rod can do only what a rod can do.  So these are the first principles of casting.  The human responses to these principles is varied.  And, the ways that humans think about their responses develops systems and dogmas that may or may not address the actual mechanics of the system.  

 

I guess we are getting to the esoteric song of songs.

 

Bill 

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Bill ....

 

I placed your glossary attachment in this message.  Forgive me for changing the heading to reflect the fact that it is yours.

 

I agree that for most casts translation and rotation do occur simultaneously.  To me they appear to occur in ever changing relative amounts as the cast proceeds to conclusion.

 

Re. "A rod can do only what a rod can do" :   As I see it a rod can "do" only one thing .... STRAIGHTEN.

 

We might be able to study the cast better by distilling it down to pure mechanics of rod and line movement as we take the human caster out of the picture.  A mechanical casting robot of some sort would be required.  This has been attempted but never perfected.

 

I understand that one was made to study the golf swing .... called the "Iron Byron".  Expert golfers have told me that no single golfer actually swung the club exactly the way the robot did.

 

Problem is that most of us look at fly casting as being performed by human beings as a way to fish.  To us, distilling and sterilizing this effort would be to make it of interest only to pure scientists.

 

Re. the GLOSSARY :

 

First, let me applaud your statement on some of your definitions being, "...as they appear to me at this time. "

 

No one or group in the field of fly casting has come up with a glossary which has gained general consensus.  Not sure that is even an achievable goal.

 

We, on the FFF CBOG Glossary Committee who have been working on this for years still have not yet had our starting definitions approved by our own Board.

 

Others, including Sexyloops.com have come up with a list of definitions to serve as their glossaries.

 

I look at all of the ones I've seen as "working definitions".  They all work wilthin their own frameworks despite lack of cohesion with others.  Nothing "written in stone on the mount" !

 

Gordy

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