Walter & Group...
From Walter Simberski on the terms "concave" and "convex" :-
Gordy,
Whether we call it a concave, convex, purple, or a
Sagittarius path of
the rod tip it really doesn't matter. The things
that matter are that we all
agree that a given path of the rod tip results in
a given loop shape and
we all agree on a common name for that path. I agree
that it may be
easier for some to think in terms of, "just like a
convex
lens I view the path of the tip bulging towards me so the
logical
description is a convex path", but I presume that the person or
persons
who decided on concave took the view that from the instructor's frame
of
reference the path appears concave and they
meant the term to be used
to convey information to other instructors.
Cheers
Walter
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Walter... Or a sine wave, for that matter. I think most of us know what is meant by reducing it to simple terms expressed as we have for years. No need to reinvent the wheel, here.
Gordy
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From Elie Beerten on compound concave and convex fly line tapers:
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CONCAVE & CONVEX COMPOUND FLY LINE TAPERS
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Elie...
First of all, you may have a copy of MODERN FLY LINES which had a misprint. I recall that was a mixup of the labels below the two diagrams, one on page 79 and the other on page 80. With later printings that was corrected. After the first printing was distributed, I assigned the reading of this book to my MCCI candidates I was coaching. To make sure they really DID read it, I required that they report to me the one misprint in the book !!!!
The rate of the taper whether straight, convex-compound or concave-compound determines the rate of dissipation of energy as the forward taper unrolls. (Same is true of leader designs.)
Greater control of this rate of energy dissipation can be achieved by further modifying the tapers. This is accomplished by designing them as concave or convex tapers. Even greater control can be achieved by making these concave or convex tapers as irregular tapers, the most common being an irregular convex-compound taper. Bruce Richards describeds this taper in paragraph 2 on p.80.
The convexity or concavity is subtle.... not enough that you or I could really see. One would have to use a micrometer at short intervals and plot the curves to document it.
Sometimes we'll purchase a line which has no real belly ..... one which seems to have a long straight taper from the tip all the way to a very short rear taper, the remainder of the line being shooting line. The TRIANGLE TAPER is one such line. Even this line, however, has a gradual slightly non-uniform convexity to what seems to be a straight taper... and is therefore properly classified as a long compound-convex taper. (Here, the word "compound" refers to the fact that the taper has more than one rate of convex increase in diameter.)
This line is considered the one which is easiest to roll cast .... AS LONG AS THE CASTER STILL HAS SOME OF THE REAR END OF THE FORWARD TAPER IN THE TIP TOP. Translation: This line may be best for short distance roll casts with reasonably soft presentation. If the designer had made that forward taper a long concave - compound taper, energy might well be dissipated a bit too soon... especially if a long gently tapered leader is used (as is often the case when fishermen use these lines.) In that case, the leader might not turn over at all and control of presentation lost.
Gordy
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