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Search found 1363 matches

by Merlin
Sun Feb 23, 2020 8:32 am
Forum: Flycasting Physics
Topic: Statements that make you go Hmmm? #1
Replies: 35
Views: 2582

Re: Statements that make you go Hmmm? #1

Sorry for the confusion Gary, I meant mCL (minimum chord length) and not MCF = maximum counterflex (aging is no good). There are many possibilities in terms of "stopping" the rod, but some are more recommandable than others for specific cases (e.g. leader casting or distance casting). The biomechani...
by Merlin
Sat Feb 22, 2020 7:44 am
Forum: Flycasting Physics
Topic: Statements that make you go Hmmm? #1
Replies: 35
Views: 2582

Re: Statements that make you go Hmmm? #1

Paul, Herer is a quick check for a fishing cast (based on Matthias’s cast simulation): timing remains the same, I changed the input for the wrist in the model. Reference point Arc = 86.7 deg; min decel = -4500 deg/s2; V tip max = 23 m/s A hard stop Arc = 86.7 deg; min decel = -5900 deg/s2; Vtip max ...
by Merlin
Sat Feb 22, 2020 7:11 am
Forum: Flycasting Physics
Topic: Statements that make you go Hmmm? #1
Replies: 35
Views: 2582

Re: Statements that make you go Hmmm? #1

The stop isn’t like hitting a wall when we cast, it’s actually an abrupt acceleration leading to the stop Agree Paul, this is the caster’s constrain due to joint rotations: I think this is what can be described by a “snap”. Large deceleration means large acceleration for a given joint. This acceler...
by Merlin
Fri Feb 21, 2020 11:27 am
Forum: Flycasting Physics
Topic: Statements that make you go Hmmm? #1
Replies: 35
Views: 2582

Re: Statements that make you go Hmmm? #1

Hi Gary Interesting point. I take the words as they are to analyze the argument”: a hard stop transmits the power/energy/momentum from the rod into the line Line speed is built from the very start of the cast till RSP1 to make things simple. We can consider two main phases: from start up to MCF, the...
by Merlin
Wed Feb 12, 2020 1:29 pm
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

I used the 2D model to simulate Gordy’s cast with no line. I took known characteristics of the rod (stiffness, speed, mo) and chose a medium action type of rod to characterize non linearity and rod action (bending pattern as a function of load and pull angle). When looking at the video, it is obviou...
by Merlin
Sun Feb 09, 2020 12:43 pm
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

James Although I did not studied that point in details nor looked after publications (if they can exist), I am pretty sure that the "not so tight" grip at the very beginning of a cast and the "relaxed grip" at the end of it moderate inertial effect. It is really effective when one accelerates and de...
by Merlin
Fri Feb 07, 2020 1:52 pm
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

I thought Newton ended this to be a phenomenon when publishing his first law?! :p Second law, Bernd, but if you try to apply it to the fly rod in the classic way you will end up nowhere. This is not the simple "F=ma" but a more sophisticated version which is named the Lagragian equations. And hopef...
by Merlin
Fri Feb 07, 2020 6:50 am
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

Gary The inertial effect comes along with spring behavior. When accelerating the butt forward, rod bends under line inertia (its mass) and rod MOI. And as soon as the rod butt is decelerated, the spring energy comes back into the line just as the inertial effect adds forward speed to the line. It is...
by Merlin
Thu Feb 06, 2020 10:55 pm
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

Hi Bernd

The inertial effect is directly linked to the acceleration or deceleration of the rod butt. Bending a rod with a fixed butt will show nothing in terms of inertial effect, rod unloading under such condition only depends on rod speed (frequency, first mode).

Merlin
by Merlin
Thu Feb 06, 2020 4:41 pm
Forum: Flycasting Physics
Topic: The Whip Effect
Replies: 51
Views: 3666

Re: The Whip Effect

No problem Paul. Most answers are in the Swing Spring & Whip paper, page 7 (evolution of energy shares with carry). The inertial effect emphasises tails in the line, I forgot to mention this one. It has some wavey aspect as would say James, visible on KE curves, but I do not think that this kinetic ...

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