Understanding Casting

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andygrey

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Yes, yes I know! I'm asking where is the aggressive (high energy) movement is coming from that forms the transverse wave - the small rod tip movement alone doesn't look enough - unless, and god forbid, it's loading and unloading. A bit like a spring. (Aaarghhh!)
Jeez... You lead by saying 'Yes, I know!' and then go on to quite patently show you DON'T know!!!
Again for the hard of hearing... Amplitude is not a measure of energy!!!!!
 

Tangled

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Jeez... You lead by saying 'Yes, I know!' and then go on to quite patently show you DON'T know!!!
Again for the hard of hearing... Amplitude is not a measure of energy!!!!!
Alternatively, you're not understanding what I'm saying.

"It turns out that the amplitude tells you how much energy is in the wave. A high amplitude wave is a high-energy wave, and a low-amplitude wave is a low-energy wave. In the case of sound waves, a high amplitude sound will be loud, and a low amplitude sound will be quiet. Or with light waves, a high amplitude beam of light will be bright, and a low amplitude beam of light will be dim."

But never mind, you've missed my point.
 

andygrey

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Alternatively, you're not understanding what I'm saying.

"It turns out that the amplitude tells you how much energy is in the wave. A high amplitude wave is a high-energy wave, and a low-amplitude wave is a low-energy wave. In the case of sound waves, a high amplitude sound will be loud, and a low amplitude sound will be quiet. Or with light waves, a high amplitude beam of light will be bright, and a low amplitude beam of light will be dim."

But never mind, you've missed my point.
Different type of 'waves'. You can't compare the behaviour of sound & light waves with a wave moving down a fly line which has both X and Y components. The energy in soundwaves for instance move backwards and forwards, not up and down and they don't have any mass, we just represent them that way as the air is being squeezed and relaxed that cause them to go 'fat and thin'.
 
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Tangled

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Different type of 'waves'. You can't compare the behaviour of sound & light waves with a wave moving down a fly line which has both X and Y components. The energy in soundwaves for instance move backwards and forwards, not up and down and they don't have any mass, we just represent them that way as the air is being squeezed and relaxed that cause them to go 'fat and thin'.
I think you've caught me at the wrong moment. I'm reading this thread


Which explains that we actually understand very little at all, and agree about nothing. If we can't even establish that a fly line cast is a waveform or not we're not going to resolve anything.

And the physics is utterly horrible.
 

James9118

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That is exactly how science works James. We make observations and then try to explain them. I'm not making a claim, I'm asking if you can explain the observation that a very small movement turns into quite a large one.

This is exactly my point. The movement is tiny, for that small movement/force to finish as a big movement in the fly leg something is happening. My question is what is it? And why does a large movement with an aerial mend not do the same?

How is a transverse wave that propagates down the fly line under tension not a wave?
Why are you ignoring the other half of Newton's 1st law - the part that says that other forces act against continued movement?

You're confusing yourself here, I'm asking questions not making statements. I asked to see evidence of real life casting where the tail grows - instead of the staged ones which had all sorts of other things going on - and now you and others have provided them. Thank you, that was useful.
I can't believe I'm still going on this, but here goes:

I've explained many times about how the dip grows - line is put in motion in a certain direction and it continues to move in that direction because there's nothing to stop it. (I will add more to this below, because I've now got a better sense of where your confusion is coming from).

Are you aware that a wave in the rod-leg is a completely different beast to a 'wave' in the fly-leg? This is because of the difference in tension between the two. In the rod-leg waves, such as aerial mends, behave much more predictably - they do not grow in amplitude (if anything they shrink) and their progress is dependant on the tension there. The tension in the rod leg arises from the change in momentum of the fly-leg (as it slows as it enters the front of the loop) and the friction of the line in the rings (or the perhaps the line is being held in a none shot cast). So you have equal and opposite forces in the rod-leg and hence tension.

Now, this is a really vital bit that you haven't appreciated - the tension in the fly-leg is not the same at all. One end of the fly leg is not tethered at all - it's free to move without constraint. If there was significant tension in the fly-leg then F=ma says it must accelerate throughout the cast. Now this gets in to a more complex part of the physics that should be left for later, as mostly the fly-leg slows down (from measurements made) although there are points where it accelerates. However, from the point of discussing tails, to say it's equivalent to a wave travelling down a tensioned string is fundamentally wrong.

So again, it's for you to explain the forces that will stop that portion of the line from continuing on the path it's on, bearing in mind that the fly end is not tethered.

A staged tail is absolutely the same as an unintentional one. I (and lots of other contributors) can throw tails like the one Flip Pallot chucks in the video on demand, using the same 'mistake' as he dropped into.

So again to summarise - waves in the rod-leg (mends etc.) behave as you'd predict from a string under tension. 'Waves', (I prefer dips) in the fly leg are fundamentally different due to lack of tension. (This is why I've repeatedly said it's a 'wave analogy').
 

ohanzee

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This is exactly my point. The movement is tiny, for that small movement/force to finish as a big movement in the fly leg something is happening. My question is what is it? And why does a large movement with an aerial mend not do the same?

If you do a snap z the movement of the rod tip that sends a loop into the air is for me usually about 6 inches, this lifts the whole line off the water to form the top v shape of the z, if you let it drift in the air..I sometimes take a few paces along with it while it glides effortlessly just to look cool, it gets bigger, it grows..from a 6 inch v shaped snap into a big v shaped thing in the air.

You can do the same vertically and snap a loop back toward you and catch the fly in your hand..again just to look cool like me :) , I think this answers your small movement that translates to a big movement conundrum, and also shows that shapes cast in, intentionally or not, grow, develop, propagate, it's really just what a line does.

Deliberately unphysicsy.
 
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Tangled

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If you do a snap z the movement of the rod tip that sends a loop into the air is for me usually about 6 inches, this lifts the whole line off the water to form the top v shape of the z, if you let it drift in the air..I sometimes take a few paces along with it while it glides effortlessly just to look cool, it gets bigger, it grows..from a 6 inch v shaped snap into a big v shaped thing in the air.
Snap movements are actually powerful; the trick with snaps is the acceleration and sharp hairpin change of direction. It's a high energy manoeuvre.
You can do the same vertically and snap a loop back toward you and catch the fly in your hand..
Yes, I used to be impressed with that trick until I worked out how easy it was. But sshh! don't tell anyone.

I think this answers your small movement that translates to a big movement conundrum, and also shows that shapes cast in, intentionally or not, grow, develop, propagate, it's really just what a line does.

I'm beginning to understand the conundrum a little now, I think. But it's horribly complicated and not at all settled. The experts can't even agree what kind of physics to use to describe it. But that's fine, that's what makes it interesting. And lucky we have the evidence of our eyes.
 

ohanzee

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What are the thoughts on unwanted waves in the leader left over from the previous back/forward cast?
Do they iron out in the next forward/back cast? or still ping around after returning in the opposite direction?
 

Tangled

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What are the thoughts on unwanted waves in the leader left over from the previous back/forward cast?
Do they iron out in the next forward/back cast? or still ping around after returning in the opposite direction?

Well this and related questions is what I'm really interested in because, to be perfectly honest, in a fishing context, I couldn't care less about tails unless they wreck my leader.

Distance casters care a lot about tails because they're inefficient in a cast; anglers should care about them because of what happens with their fly. (Yes I know distance casters need the fly to turnover too.)

If you look at Flip's video that small blip in the fly line at 1:28 totally trashes the leader.
 

geenomad

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A final contribution from me. For poor lost souls looking to understand the mechanics of casting in general and tailing loops in particular my advice is to go back to where people who clearly speak with authority have spoken and agreed.

For my $A0.02 casting discussions that morph into arguments or pseudo arguments about mechanics offer very little clarity and add to rather than subtract from, confusion suffered by anglers who want to improve their casting.

If like me you want to make accurate fly fishing casts at various lengths from very short to pretty long the takeaways from this thread are actually all there in the first 15 pages.

For your standard overhead casting you need to make the rod travel in as straight a line as possible (SLP) for as long as possible. Doing that concentrates and optimises the force going in the intended direction of the cast. That necessarily implies that we have a clearly defined intention as to exactly where we want the cast to go.

It helps a lot with a neat SLP to go easy on the power application and trust in the (net) Force and joy of casting efficiently, with control and therefore accuracy.

If your acceleration gets a bit lumpy because you get a bit punchy the risk of a poor cast and a tailing loop both increase substantially.

Cheers
Mark
 

Tangled

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A final contribution from me.

That would be a shame but I understand why anyone who's been through this process would not want to do it again.

But just before you go, I know you're a big fan of straight lines. So wtf is going on here?

 

PaulD

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A final contribution from me. For poor lost souls looking to understand the mechanics of casting in general and tailing loops in particular my advice is to go back to where people who clearly speak with authority have spoken and agreed.

For my $A0.02 casting discussions that morph into arguments or pseudo arguments about mechanics offer very little clarity and add to rather than subtract from, confusion suffered by anglers who want to improve their casting.
Cheers
Mark
Some 50+ years ago, when I was commencing my fly fishing journey, I contrived to scrape a bare pass in O Level Physics. Over subsequent years my knowledge and understanding of the subject shows no measurable progress. However, during the same period, my ability to cast a fly has improved remarkably and I don't think the progress has anything to do with my academic choice of Fine Art, Painting & Sculpture.

In common with many people, I 'taught' myself to cast. In the 60s there was no internet, no Youtube videos, no video players, albeit I did find a copy of T. C. Ivens, 'Still Water Fly Fishing' in the mobile library van and the section on casting was helpful. Over time I became a 'competent' caster but real improvement didn't happen until I decided I needed a broader, deeper understanding of casting because I was finding myself in fishing situations where my knowledge, skills and understanding let me down.

I didn't follow the Tangled path - quoting internet pages - looking at videos and 'asking questions' without actually knowing what the question was. By contrast, I took myself to somewhere where people were casting and initially that was an AAPGAI weekend at Caer Beris and what a learning experience it was! I was initially 'assessed' by Glyn Freeman and the late Doug Holloway - they asked me to show them a roll cast, which I did and they said it was good . . . but then asked me 'What I'd done?' A bloody roll cast went through my head but it was the first time I'd had to consider breaking down and explaining the 'mechanics' of what I'd done. Thinking about each aspect of the cast, how and why the position of feet, arm, hand and rod contributed to the outcome. Later, I spent some time casting with Lasse K and Lee Cummings - well, mostly watching - and if memory serves me, I managed 115 - 120ft with my 5wt, TCR and Scientific Anglers Mastery Distance line!

It was through this weekend, the conversations with casters, the opportunity to watch, listen to opinions and practice in front of others that set me on the instructor path, ultimately with GAIA. The language of casting is often challenging - there is a great deal of quasi-scientific 'chatter' from people who do not have the knowledge and experience of James but it's mostly irrelevant and does nothing to aid or improve the ability to cast well.
 

LukeNZ

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Come off it, you're as addicted as I am!

It is. But even small mends are a foot or so in size and they are pretty much the same size as the rod deflection that caused them aren't they? If you want a big deflection you don't use power, you used a larger rod movement.


Sure but what I've been saying for some time now is that the actual deviation in the tip path that creates the concavity is very small and out of scale to the size it finally becomes. So there's more energy in that wave than there is in a deliberate mend; fair enough, that's interesting.

The energy in the loop is forward, in the direction of the cast. The energy in the tail is at 90 degrees to that. We're told that it's the rod tip shortening and lengthening that creates the dip and we can see it a small concavity in the fly leg. How much energy is in that short movement and where is it coming from/ (Obviously the caster, but what component of the cast?)
Tangled, in all seriousness, wtf do you know about fly fishing, let alone the advanced aspects and proficiencies that underpin the fundamental principles?

Just putting it out there; and really dont think that I am guessing, when I suggest, probably much less than fark all..

Sorry to be your reality check on this.

🙃
 

LukeNZ

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Be quiet child, the grown ups are talking.

How would this be; post a short video of your casting (off either shoulder..) with either single handed or spey rod; doesnt have to be more than 80 ft. if that is your comfort zone, and I will post my chops, with both.

Then; lets compare notes about children's contributions, and understanding casting..

In other words, put your money where you mouth is, so to speak; remembering that if either of us doesn't, post / then we surrender our fly fishing credibility.

Deal?

🙃
 

torrotxo

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Just to summarise.
 

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