|
Walter & Group...
[GH] I WILL BE AWAY FOR A FEW DAYS.
I'm looking forward to fishing at Chokoloskee with Bob Andreae for reds and snook!
Gordy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[GH] Here is Ally Gowans' discussion of his results after performing the rope experiment. My results were the same:
Hi Gordy,
The reason for the rope and no rod was to eliminate the complication of the
rod - it's the line that we cast - a rod is firstly an arm extension. A
flexible rod has some important functions - like the springs in a shock
absorber it smooth's out some discrepancies in the stroke - as others have
said its compression allows a straighter path to be made - and of course its
discharge made quickly can transfer energy to the line and speed it up. If
line launch did not occur during a cast the likes of the 170 degree cast
would not be successful.
When you performed the rope tricks I hope that you noticed that the main
influence on the direction that the line took was where it started from and
even if you accelerated at an angle to the line it would still have the
tendency to go 180 degrees to its initial position. So it verified the 180 "
degree rule" and by going a direction different to the propelling stroke it
broke the "line follows the rod tip" rule. You should have been able to
identify differences in the loop size/shape in each of the tests. The main
purpose of the tests was to illustrate momentum in action.
I asked you to move your arm through 180 degrees whilst pulling the rope.
The line would have launched somewhere around halfway through the motion
because after that there would discrepancy between the line momentum and the
direction of your hand.
Clearly a very short line is more influenced by the rod tip because its mass
is closer coupled to the rod tip. You can easily imagine how a spinner
closely coupled moves. But if you place the spinner a longer distance from
the rod tip it becomes less respondent to directional changes. Fly lines
behave similarly but their mass distribution is harder to imagine for some.
A shooting head is the closest fly casting comparison to a spinner. I once
did a fly casting demonstration to a group of instructors using a spinning
outfit with a short shooting head attached, it worked perfectly well but I
doubt if all the observers understood my purpose, to demonstrate the
similarities that exist between all casting techniques.
I hope this makes sense to you, it's late here!
Best regards,
Ally Gowans
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>From Walter Simbirski:
Gordy,
I find people get confused when thinking about Newton's laws and fly line because fly line is flexible. Rather than thinking about what individual sections of the line are doing I find it helps to look at what happens to the line's center of mass.
For example, if I lay a rope out on the ground and pull one end to the side the entire rope could move sideways, which isn't likely, or the rope can bend in response to the applied force which is what we do see happen. When I pulled on the end of the rope where did the center of mass of the rope move to? Now think about how I actually applied force in relation to the rope's center of mass rather than the point where I applied force to the rope.
Does the direction of the applied force and the resulting displacement of the center of mass begin to make sense?
Thanks
Walter
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[GH] Walter,
To me, it does. Good way to look at it, especially for non scientists.
Gordy
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To be removed from this mailing list, please click here to unsubscribe
|