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Physics Q/As for the casual reader

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Paul Arden
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Physics Q/As for the casual reader

#1

Post by Paul Arden » Sun Aug 16, 2020 6:08 am

Hi chaps,

So I think it is a good idea to formulate a list of physics questions that could be used to understand the physical workings of the cast. I’ll throw in a few here. I think however the questions themselves will need some work on their wording and even their intent. So if we can agree to the questions and tweak them to be excellent questions then this would be a start!

Also I don’t know how many questions are required hence this topic :) I would imagine about 50.

How does a flycasting loop unroll/work?
How does hauling work?
What is the purpose of the anchor in Roll/Spey casting?
How does a Roll Cast work (D-loop)?
What is the purpose of “rod loading”?
What is the function of the fly rod in fly casting?
How does Tip Path influence loop shape?
How does a Loop form?
How does pull back work?
What is a tailing loop wave and how does it progress?
Why does a cast “collapse” if the casting stroke is started before the previous loop has straightened?
What is the purpose of fly line tapers?
What is the purpose of leader tapers?
How does a loop stay aloft?
How does a curve cast bend the line?
How do mends work?
What is delayed rotation and how does it work?
How should hauling and the casting stroke be combined?
How does air density affect the loop?
How does a rod damp?
How does the Loop morph?

If we can make a list of questions, I can list them as one list. We can add or remove questions from the list, rework the wording of the questions so that they work together as a package and finally I can give them a logical sequence.

Then I can list all of the questions on an introductory fc physics page with links to the Board Q/A and discussions. That way all the information is collected and can easily be distributed.

What do you think? Thanks guys!

Cheers, Paul
It's an exploration; bring a flyrod.

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John Waters
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Re: Physics Q/As for the casual reader

#2

Post by John Waters » Sun Aug 16, 2020 6:56 am

Yep, good idea Paul.

John

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Graeme H
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Re: Physics Q/As for the casual reader

#3

Post by Graeme H » Sun Aug 16, 2020 10:41 am

There are some perpetual questions in that list - ones I don't think we'll ever agree on the answers to (we've already covered them and they are still unresolved).

But some of them are worth clarifying, for sure.

Cheers,
Graeme
FFi CCI

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Paul Arden
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Re: Physics Q/As for the casual reader

#4

Post by Paul Arden » Sun Aug 16, 2020 11:37 am

Hi Graeme,

That’s fine. If we run into those problems we can publish multiple answers. In fact for me this is one very compelling reason to work through this project. Ie to see the “lay of the land” :)

This way there is no need for perpetual arguments.

Cheers, Paul
It's an exploration; bring a flyrod.

Flycasting Definitions

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gordonjudd
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Re: Physics Q/As for the casual reader

#5

Post by gordonjudd » Sun Aug 16, 2020 12:32 pm

How does Tip Path influence loop shape?
Paul,
I would modify that to ask, 'How does the Tip Path from RSP0 to RSP1 influence the initial loop shape?" Loop morph will have a big effect on the loop shape as it propagates.

A related question would be "How does the tip path from RSP to MCF influence the initial loop shape?"

The caster has a big influence on the path from RSP0 to RSP1. Not so much from RSP1 to MCF.

I would also add the very basic question "How is the initial line speed at RSP1 produced?".

Gordy

Torsten
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Re: Physics Q/As for the casual reader

#6

Post by Torsten » Sun Aug 16, 2020 4:27 pm

Is internal friction an important factor for fly rod design?
What is the first, second (etc.) natural frequency of the fly rod and how does it influence fly casting?
Does the haul bend the rod?
When does the loop formation start?
Is a long hand translation with an extended arm more effective than a short one?
What is the typical line velocity at the launch for a long and short cast?
Is the tip bounce detrimental to the casting distance?
What's the ideal method to pick up line from the water surface?
When does the line fall down during unrolling of the loop?
Is there a most power-efficient rod-line combination existing for a particular casting distance?
Why do we need to eliminate slack?

nicholasfmoore
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Re: Physics Q/As for the casual reader

#7

Post by nicholasfmoore » Mon Aug 17, 2020 10:43 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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Paul Arden
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Re: Physics Q/As for the casual reader

#8

Post by Paul Arden » Mon Aug 17, 2020 11:13 am

I’m not looking to get answers here Nick, only a list of questions! For each question we will start a separate topic which will allow us to place the best agreed answer/s below.

viewtopic.php?f=11&t=3312

Thanks!!!
Paul
It's an exploration; bring a flyrod.

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nicholasfmoore
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Re: Physics Q/As for the casual reader

#9

Post by nicholasfmoore » Mon Aug 17, 2020 11:42 am

Ah, sorry Paul! :cool: I was confused by the Q/A :laugh:

How is a dolphin nose loops produced?
How is a U shaped loop produced?
How do you create a pointed/wedge loop?
How does tip bounce create wind knots?
Why can't you have a leader of just tippet?
What determines the correct stroke length?
How do you achieve maximum distance from a short headed line?

All the best :)
Nick M

"Memento Piscantur Saepe" :upside:

andrewparkeruk
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Location: Manchester, UK

Re: Physics Q/As for the casual reader

#10

Post by andrewparkeruk » Tue Aug 18, 2020 10:25 am

gordonjudd wrote:
Sun Aug 16, 2020 12:32 pm
How does Tip Path influence loop shape?
Paul,
I would modify that to ask, 'How does the Tip Path from RSP0 to RSP1 influence the initial loop shape?" Loop morph will have a big effect on the loop shape as it propagates.

A related question would be "How does the tip path from RSP to MCF influence the initial loop shape?"

The caster has a big influence on the path from RSP0 to RSP1. Not so much from RSP1 to MCF.

I would also add the very basic question "How is the initial line speed at RSP1 produced?".

Gordy
Gordy, I think you have lost the casual reader :) ...

Andrew

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