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Covered topics /how it works

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Lasse Karlsson
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Re: Covered topics /how it works

#91

Post by Lasse Karlsson » Sun Aug 16, 2020 9:23 pm

Hi James

Aren't all models flawed, but some are useful?

Still having a hard time getting my dumb head around this, so if I next week when I get gome, take the 9 wt dt and 4 wt dt out inro the field, false cast 70 feet of each out the tip of the rod, then chop chop bot at 35 feet back from the tip, join the fat end of each (where my scissors met the lines) with a smooth connection (I would probably go with one of these
http://www.sexyloops.com/articles/smoot ... ions.shtml

http://www.sexyloops.com/articles/smoot ... ited.shtml
)

Then I will have a hard time arielising that 70 feet head?
Apart from that sounds a bit like a rio single hand spey line, I can't see why it should be really hard, but I might miss something and would be happy to give it a go if I understand correctly 😊

Cheers
Lasse
Your friendly neighbourhood flyslinger

http://www.karlssonflyfishing.com

***Bring Mark back!!!!!! ***

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James9118
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Location: N.Wales

Re: Covered topics /how it works

#92

Post by James9118 » Sun Aug 16, 2020 9:30 pm

Yup, as long as the #9 (or the heavier of the two) is at the front i.e. nearest the leader.

I'd be really interested to see how you get on.

Cheers, James.

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Graeme H
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Location: Perth, Western Australia

Re: Covered topics /how it works

#93

Post by Graeme H » Mon Aug 17, 2020 8:28 am

James9118 wrote:
Sun Aug 16, 2020 6:51 pm
To my mind the current models do not predict this effect (unless I've missed something), as such perhaps the models are missing something fundamental.

Cheers, James
Transverse waves.
FFi CCI

nicholasfmoore
Posts: 338
Joined: Tue Jul 16, 2019 1:41 pm

Re: Covered topics /how it works

#94

Post by nicholasfmoore » Mon Aug 17, 2020 11:43 am

Hi Paul,

What's an anchor? A portion of the fly line and/or the leader on the water.

Purpose of the Anchor in roll/speys;

Stops the fly going into trees/bushes, sheep etc behind you by 'anchoring' the tip of the fly line on the water.

It enables you to get all the momentum going in the correct direction (forward cast) :yeahhh:

A sliding anchor is inefficient, as the tip gathers too much momentum away from the intended target. When you start going on the forward cast, some energy goes into enabling the tip to move away from the target.

All the best
Nick M

"Memento Piscantur Saepe" :upside:

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flyfisher666
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Location: Ryd, Sweden

Re: Covered topics /how it works

#95

Post by flyfisher666 » Mon Aug 17, 2020 6:03 pm

Q: How does a loop morph?
A: From big to smaller.

Q: Why does a loop morph?
A: As the loop propagates away from you the tension force acting on the rod leg part of the loop gets more parallell with the fly leg and therefor "pull" the loop tighter.

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gordonjudd
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Re: Covered topics /how it works

#96

Post by gordonjudd » Mon Aug 17, 2020 6:05 pm

To my mind the current models do not predict this effect (unless I've missed something), as such perhaps the models are missing something fundamental.
James,
I expect that Gatti-Bono's equations governing the dynamics of loop generation are quite complete. The problem is they are so complicated (six equations six unknowns that earned her a PhD while developing a technique to solve them) that no one on this forum is going to be able to apply them.

Something more basic to the propagation of a loop in your reversed line set up has to do with the lower tension (positive acceleration force) provided by the rho_l*v_tangential\(^2\) of the #5 line trying to overcome the larger drag forces and mass of the #7 line behind it.

Gordy

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flyfisher666
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Re: Covered topics /how it works

#97

Post by flyfisher666 » Mon Aug 17, 2020 7:01 pm

James9118 wrote:
Sun Aug 16, 2020 9:08 am
Hi Lasse,

For me yes, it became pretty ugly - a bit like a casting a WF with an abrupt rear taper with too much overhang.

Cheers, James
It's more or less what it is isn't? A wf with no backtaper and a really thick running line. Did you try it the other way around? The #5 closest to the leader?

//Joakim

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James9118
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Re: Covered topics /how it works

#98

Post by James9118 » Mon Aug 17, 2020 7:26 pm

As I've said many times the Gatti-Bono paper is one of the typical unvalidated piles of cack that gets reeled out time and again as being the final word on fly casting. It's not, I doubt she can fly cast to save her life - if she could, she would have got out there and done some actual validation. Incidentally, she ended up working in one of the US labs that is equivalent to the one where I work, I hope she does a better job there than on her fly casting paper. I can't see why solving the differential equations in the paper would merit a PhD, but then again they give them out like bog roll in the US.

My test isn't a 'reversed line set up', it's a bog standard WF with no rear taper. Your statement implies that the #5 is somehow towing the the heavier line - this is nonsense. You haven't asked any questions at all about why my casts failed because you're not interested, you just want to make it fit with your confirmation bias.

James.

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gordonjudd
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Re: Covered topics /how it works

#99

Post by gordonjudd » Mon Aug 17, 2020 8:12 pm

You haven't asked any questions at all about why my casts failed because you're not interested, you just want to make it fit with your confirmation bias.
James,
To the contrary, I would like to see your videos that show the details of why your casts failed.

I was just pointing out that it is easier for heavy section of line to tow a lighter one, rather than the other way around. If that does not make sense to you I would like to lhear about how you see the problem. Videos and data to validate those views are most welcome.
Gordy

Bianchetti Ivan
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Re: Covered topics /how it works

#100

Post by Bianchetti Ivan » Tue Aug 18, 2020 8:36 pm

Excuse my ignorance, while the line is in flight the front slows down more than the back, if the tension serves to remove the part that slows down, the rest will probably keep its position and speed?

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