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Analysing loop propagation

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Graeme H
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Location: Perth, Western Australia

Re: Analysing loop propagation

#41

Post by Graeme H » Tue Sep 22, 2020 10:30 pm

Flu cast being a fly cast? Yes. The wave is propagating upwards (but don't forget gravity.)

I'll post a video tonight showing the wave travelling upwards. I've worked out I can do this without a 50m tower - the balcony at work is high enough.
FFi CCI

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Merlin
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Re: Analysing loop propagation

#42

Post by Merlin » Tue Sep 22, 2020 11:59 pm

Post #19
The tip trajectory. You may include a circle if you wish. At some time it does not represent a mend anymore.

Errare humanum est, perseverare diabolicum.

Merlin
Fly rods are like women, they won't play if they're maltreated
Charles Ritz, A Flyfisher's Life

Bianchetti Ivan
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Re: Analysing loop propagation

#43

Post by Bianchetti Ivan » Wed Sep 23, 2020 4:46 am

If I throw my line against a wall, the wave stops, why does the rest of the line all end up against the wall anyway?

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Graeme H
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Re: Analysing loop propagation

#44

Post by Graeme H » Wed Sep 23, 2020 6:34 am

Bianchetti Ivan wrote:
Wed Sep 23, 2020 4:46 am
If I throw my line against a wall, the wave stops, why does the rest of the line all end up against the wall anyway?
Because the fly leg is also a projectile. This thread is about loop propagation, but the two are closely tied.
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Graeme H
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Re: Analysing loop propagation

#45

Post by Graeme H » Wed Sep 23, 2020 6:35 am

Merlin wrote:
Tue Sep 22, 2020 11:59 pm
Post #19
The tip trajectory. You may include a circle if you wish. At some time it does not represent a mend anymore.

Errare humanum est, perseverare diabolicum.

Merlin
So which of the casts was the last transverse wave? And why?
FFi CCI

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Graeme H
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Location: Perth, Western Australia

Re: Analysing loop propagation

#46

Post by Graeme H » Wed Sep 23, 2020 7:02 am

And here we have the results of the thought experiment I mentioned earlier, now presented as a physical experiment:




What you should observe here are a few quite obvious transverse waves that propagate upwards towards the tethered end of the line. If it wasn't tethered and the line was free to fall, the loop would be rising at a similar rate to the line's decent, making it appear to float.

During the last cast, I've asked my assistant to release the tether as the wave rises. That transverse wave immediately becomes a loop. That is, as a caster I did nothing with the rod tip to transform this wave into a loop. All that changed was the release of the tether. (Got that Merlin? I did not alter the tip trajectory - the wave had already been propagated and was rising at the time that it became a "loop wave", whatever that is ...)

So, how do you guys explain the final loop that was clearly a transverse wave before the release? If all I showed was the line at the 30 second mark (see below) would you have called it a loop or a wave? Is it now a loop or is it still a wave?
failed_wave.jpg
Cheers,
Graeme
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Bianchetti Ivan
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Re: Analysing loop propagation

#47

Post by Bianchetti Ivan » Wed Sep 23, 2020 7:13 am

Graeme H wrote:
Wed Sep 23, 2020 6:34 am
Bianchetti Ivan wrote:
Wed Sep 23, 2020 4:46 am
If I throw my line against a wall, the wave stops, why does the rest of the line all end up against the wall anyway?
Because the fly leg is also a projectile. This thread is about loop propagation, but the two are closely tied.
Excuse me it is only to understand, not to counter an argument that exceeds my knowledge, if the loop were a wave, when it hits the wall it should rise and not go out, but perhaps it is a belief of those who do not know things.

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Merlin
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Re: Analysing loop propagation

#48

Post by Merlin » Wed Sep 23, 2020 12:21 pm

Graeme

You create a completely artificial situation to justify your theory (how many followers). Do you cast vertical lines when you fish?

In the north hemisphere at least, our lines are somewhat horizontal as we start the cast. It seems not to be the case in Australia.

Please do not try to convince me again, try with someone else.

Thanks

Merlin
Fly rods are like women, they won't play if they're maltreated
Charles Ritz, A Flyfisher's Life

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Graeme H
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Re: Analysing loop propagation

#49

Post by Graeme H » Wed Sep 23, 2020 12:48 pm

Spreadsheets.
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Paul Arden
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Re: Analysing loop propagation

#50

Post by Paul Arden » Wed Sep 23, 2020 1:04 pm

Yep that doesn’t help me at all :D I suppose the differences are tethered end and gravity. But I have definitely moved two steps closer to James :D

Sorry I brought it up :cool:

Cheers, Paul
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