Casting mechanics - Answers 8

[GH] In discussions such as these, many different opinions will appear. This is as it should be for it takes us from reliance on dogma and elevates the discussion to a higher level as it makes the reader think. After weighing the pros and cons of each opinion, he can come to his own informed conclusions.

''When something translates in scientific terms, it simply moves through 3-D space from point A to point B. While it's doing this, it may be rotating, it may be changing color, it may be laughing, it may be getting smaller. .. But it is moving through 3-D space. As in, its center of gravity has changed position. Many people think that translation implies linear movement, but it doesn't. You could move from A to B in an infinite number of paths, but there's only ONE linear path. In the grand scheme, that's the one that I'm trying to make my thumbnail (and the rod tip) imitate.''

The point is.. that an object can be translated and rotated at the same time. The change of position can be simply explained by first translating the object from position A- to position B and then rotating it, or by rotating it first and then translating it. In either case all parts of the object remain parallel while it is translated and then it rotates or vice versa. This clearly isn’t how we cast though. The process in real life involves both things co-occurring, so as the rod is being translated it is also being rotated.

[GM] Correct: Let me change the order of the phrases in my statement above and it will be clear that we have just made the same point. “We are adding stroke length via translation - unless we are casting solely from the wrist, with the use of no other joint (elbow, shoulder, spine, legs).

"If I take the same rod and make two casts.... one with a good match between casting arc and rod bend for rod tip SLP ... .and the second with the same casting arc and greater rod bend due to greater application of force, I daresay I'll have a concave rod tip path leading to a tail."

In both instances, using the wrist as a tracking point, I plotted the path travelled from the first discernible motion forward until the end of delivery with red dots. The green line represents a straight line from both extremes. There is also a purple line indicating the extrapolated point where the rod passed a position perpendicular to the green line.

What is of greatest interest in the terms of this discussion is the wrist path indicated by the red dots. Both indicate a relatively large deviation from a straight-line path. Neither caster was necessarily aware of the shape of the path though they knew it was not a straight line. These motions are a form of self-optimization that the most highly skilled casters apply, usually unconsciously. Then others, trying to catch up to them, begin to emulate the motions.

This I think is a potential source of confusion. The entire bony body, almost, is made up of linked levers which, by rotating, one with another, can produce translations or translations and rotations. If we draw a straight chalk line on a blackboard, horizontal, vertical or oblique, the chalk in hand has translated. This is evidenced by the line and this line has been generated by the combination of rotating levers in our arm. In fact if we draw a circle on the blackboard the chalk will still have translated, this is curvilinear translation, also generated by the linkages between our upper arm, forearm and wrist, even our fingers. So, if we apply a rod centric view of events, any compound movement will either produce both rotation and translation of the rod or just translation. With a compound movement, that is, more than one lever operating at the same time, you cannot make a rotation only movement of the rod, too much rotation, yes, but only rotation, no. This is also true if you hold an rod in your hand and rotate from the shoulder with the elbow and wrist completely rigid, then the rod in the hand will still have rotated and translated even though the whole shebang, arm and rod viewed as a single unit, has only rotated around the shoulder joint.

Aitor has video of Alejandro Vinuales casting a very considerable distance using a completely rigid rod with a very tidy SLP and beautiful tight loops. It too won’t bend so, no bend equals what size arc exactly ?... some ?, none ?..you can’t match an arc to a bend that doesn’t exist... J This SLP is managed entirely by hand path, the shorter the rod the easier it is to do.

I have watched that video numerous times and have slowed it down even more to study it. Contrary to popular opinion, that rod is bending during the cast. It can be seen in the video between :06 and :08. It is slight compared to any modern rod and there doesn’t appear to be any counter flex, but is does bend.

I am guessing the “rod” is made from a tubular material, possibly aluminum. European broomsticks are usually metal (aluminum) tubing from what I remember. Here is the U.S. they are often still made from wooden dowels about 1 ¼ inches thick. Either way, they will bend when sufficient rotational force is applied to one end and a load applied to the other (even without a load due to inertia). The thick wooden stick will require more force to make it happen, but let’s say we have a 20 foot stick, it won’t be as hard to make it bend. Unless the rod has absolutely no elasticity it will be subject to spring forces. If it has absolutely no elasticity, it will be highly brittle and will be prone to breaking when rotated form an end or too heavy to use.

I find that some of the conclusions people make from their videos fit nicely into their own pet theories, but when looked at with a critical eye one can find elements that have been overlooked. These elements can show that the example demonstrates features of the cast that could detrimentally influence the interpretation of events. The video above illustrates my point. It is not a fair illustration of what is trying to be proven. Having said that, hand casting, without a rod proves the point better. It illustrates SLP without possibility of the “rod” bending.

As you are aware, I challenge the idea that we exclusively “Match the Arc to the Bend in order to get a SLP at the tip” so I am still intrigued to know the answers to the questions “How do we match the Arc to the Bend in order to get a SLP at the tip?” or “how do you teach someone to match the arc to the bend in the rod” It’s a lot easier to say than it is to teach I think.. J

With beginners there are too many other ways to teach casting that are simpler. In a short session, I can’t expect someone to retain that depth of information if they only store 10% or 15% of what I say. Even during 5 – 2 hour sessions I wouldn’t bring it up. Instead, I depend on part of my third 3^rd of 5 lessons. In this, there is a discussion of what changes are necessary when using a shorter or longer line. The exercise is an adaptation taken from an exercise on Bill Gammels video. Starting with a 20 foot cast they have to make tight, then progressively larger loops, then back to tight. Once they have done this twice they get to add 30 inches of line and do it again. This is repeated until they reach their maximum, usually a 45 to 50 feet.

My demonstration before the exercise illustrates what changes in the cast as the line length is changed. Stroke length, casting arc, tempo, trajectory and force applied. No discussion of haul is needed, it is a beginner’s class. A secondary and probably more important skill is learned at this time. They discover that they can make any size loop they want regardless of line length. They learn how to control line for the fishing situation, whether they are casting weighted streamers or dry flys.

For more advanced casters, those who “pull the rod”, have control of their back cast, and can false cast good loops while not watching their cast and carrying on a conversation – they don’t need to be told to match the arc to the bend. They already know it intellectually, or at least instinctively.

I believe that has been part of the point you are trying to make here, some instructors don’t know this. This is probably true but you need to ask yourself - Does not understanding casting from an engineer’s point of view, or not using engineering terms while teaching, make an excellent instructor any less effective? It seems that the current mode of thinking , at least among many of the SL minions, is that if you don’t know what “I as an SL’er” knows, you shouldn’t be instructing or testing. I keep seeing comments made in various places that the candidate knows more than the examiner, and most importantly, that the situation makes for poorly administered tests and complaints.

According to an inquiry made a few months ago, there is no problem within the CICP with complaints of unfairly administered tests. The total number was fewer than you would ever imagine and you would not believe me if I told you (which I can’t, it was information discovered within a committee). The bigger problem seems to be the irrational fear some have that this is a potential problem, and the trashing of the program based upon those fears.

Another issue here is that most of those who claim to have this greater level of knowledge won’t take the time to write up an abstract, or short paper, on what it is they have discovered and present it where it matters. I do have to give credit to Mark and Bernd Ziesche for at least attempting to overcome this shortfall though I may not always agree with their conclusions. : )

The fact that some piece of information is buried in thousands of posts on the internet, does not mean it is where it can be easily discovered by the less informed. If you don’t know what you’re missing you can’t possibly be expected to know enough to ask questions about it. Also, just because one runs the “largest” forum on the topic doesn’t mean everyone concerned reads it.

My own teaching of beginners is based upon teaching physical positioning and motions of the body, after all this is what moves the rod. This includes concentrating on starting positions of the rod at initial lift and end of back cast positioning – self-analysis and self-correction. All this before we do any forward casts, and those are done in isolation before we do pickup/laydown exercises then false casting. By the time I am done with these portions of the lesson, they have already conquered 2 of the three skills I ultimately want them to leave the class with. The have learned to make a good back cast stop (#1), and they have learned to “pull” the rod forward and down, not “push” the rod (#2). The last skill I want them to ultimately leave with is the one mentioned above based upon Bill Gammels video, loop control regardless of the length of line (#3). I also stress conservation of physical energy by using efficient motion. I suspect Ally Gowans and I have similar philosophies

I have recently started experimenting with a couple of beginners, teaching how to move the cork through space and concentrating on it initially, not the rod or the line. Particularly, stressing on keeping the bottom of the cork in front of the top of the cork until late in the stroke (if you move the cork correctly the rest follows according to the six step method). This is an alternate way to enhance the “pulling” motion.

[GM] Isn’t that an example of a variable casting stroke, not a variable casting arc? I am sure he understood what he was trying to get across; he just fails to communicate it properly. Or, maybe he hadn’t cemented the differences in his mind yet. This is one of those instances in the literature where some may have taken it as gospel, not realizing the error. There is also the argument where many people might be more prone to believe an internationally known figure over someone newer into the sport regardless of their information accuracy. This is another element that must be overcome in the greater discussions within our community.

I would agree that most of us would now look at \ / as the Casting stroke. As you know, many will argue that \ // would represent the Casting stroke also while others would say it would be translation prior to the casting stroke, the stroke itself being made up of the combination of rotation and translation.

We have come a long way since books by "icons" of fly casting have been published. At the same time, I respect these authors of the past as having laid the groundwork upon which we now build. They were our pioneers. When they published, they didn't have much organized published work to study.