Gordon & Group...
[GH] From Ally Gowans (Please note his two attachments):
Hi Gordy,
Great stuff at last we are discussing casting fly lines and not just how rods waggle! Soon really is thinking about this and I believe that he and others are on the right lines. Having kicked this off I’m beginning to wonder if I’m being left behind, isn’t that fantastic!
Some comments:
" [GH] One problem lies in our not as yet having full agreement on exactly when that point (line launch) appears during the casting stroke."
[AG] Knowing the precise point or instant of line launch is not important because the line leaves a history trail that shows us the direction of the launch – and that is important.
"[GH]I can also accept your concept of the casting stroke as ending with line launch (CS - BL -Casting stroke before line launch) as reasonable."
[AG] This is discussed in different terms in the attached file – essentially when the line is launched you can drop the rod and the cast will complete.
"[GH]Your proposal that CS -AL (Casting stroke after line launch) be called "stop" does have merit because that is where the "stop sequence" must come to a halt since this is the first actual point of cessation of movement as the rod tip actually changes direction into rebound. Other contrarians may point out that this is the STOP OF THE ROD TIP. Not the "stop" of the hand or rod butt."
[AG] The importance of the STOP has to be measured since we don’t have to stop the rod to complete a cast, the direction change at the tip is sufficient to prevent further useful energy transfer to the line. However we all like to teach stops because they work very well for short casts where everything that happens is compressed into a shorter time frame.
"[GH] None of this can help us actually teach fly casting until and unless we can reduce it to simple terms which will make a difference to the student caster."
[AG] If it helps us to understand it also helps us to teach and more importantly good understanding of what happens prevents us from emphasising matters that are practically irrelevant such as maximum rod tip speed. Teaching how to cast a fly line (not a rod) is the single most important aspect of the job.
I had intended to hang on to the attachments until after the holidays but encouraged by the responses I am sending them now and I hope that in them I have explained things clearly enough.
Best wishes,
Ally Gowans
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[GH] Question for Paul Arden from Dan McCrimmon :
What is the "tension" in the loop that Paul describes? Could it be centrifugal force that maintains the loop shape (tension)? Or more correctly, dissipation of energy, via centrifugal force?
Dan
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[GH] From Mark Surtees :
Hi Gordy
“I will pick up on one of the points made – and at this time resist commenting on some of the others. “After the stop, the whole line continues to be accelerated forwards up to RSP.” – this is untrue except for very short casts, normally only a small amount of line will continue to be accelerated up to RSP…..”
Hmmm….If the rod tip, continues to accelerate up to RSP then we, I think, can assume that it is continuing to apply force to the line. In this case the “effective mass” of the line is the mass of line all the way from the tip to the fly. If we also assume that this mass hasn’t changed then it is quite safe, on the basis that F=MA, that the entire mass, i.e. the whole line, is being accelerated. Line mass distribution and/or the length of the cast have nothing to do with this. How much force, line stretch and other roddy factors come in to play clearly with respect to how much it is accelerated but generally speaking I think I can safely stand by my original statement.
“…..and the “effective mass” of the line will continue in a direction that is dependent on its starting location and the forces applied to it.”
Yep… and it will continue in that direction until another force acts upon it…no additional force, however wee….no turnover.
Mark
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