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Walter & Group...
>From Tony Loader. (I added Tim Kempton's question):
Hi Gordy,
Some thoughts on Tim’s question.
"In Jason's paper, Its not obvious why cast 4 achieved the fastest line speed at RSP (26)…did the rod bend less, and yet it had the same MCL as cast 2, the slowest (22)?"
In my very humble view, it’s more about the caster than the rod.
The rod’s length, mass, stiffness and action can influence tip path and acceleration. Any particular rod will generally respond reliably and predictably to input from the caster.
The caster can influence tip path and acceleration in a myriad of infinitely variable, different ways, such as hand path, body movement, translation, rotation, stepping, dragging, sliding, thrusting, drifting, and hauling. Since it is possible to make controlled narrow loops with virtually any rod, including a rigid rod, by appropriately applying a selection of such motions. I would be very surprised if the variation between casts 2 and 4, that Tim refers to, is even mostly attributable to the rod.
The rank beginner has no idea of what constitutes “goodness”, and the so called “intermediate caster” will always keep the rod manufacturers in business by searching for the magic bullet rather than improving his casting. The expert can almost immediately adjust his inputs so as to optimize the performance of any rod.
The better the caster, the less the rod matters.
Regards,
Tony.
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>From Bruce Richards:
Two quick comments.... The spring vs. swing contribution to line speed is highly variable, sometimes the "spring" contribution isn't much, sometimes it is a lot more. Easy to figure out though, sort of. Any good physics guy can quickly calculate tip/line speed of a rigid rod, no spring contribution. Then, tip/line speed for a flexible rod of the same length can be either measured through video analysis, or with a rod instrumented with rate gyro and strain gauge. Rotate both rods the same, the difference in tip/line speed is what "spring" contributes. Of course, rod flex contributes more than just speed, it also makes straighter tip paths and better loops possible.
I agree completely with Tim on the rod selection issue. We've all heard that the best way to know what is best for you is to "try them all". That would be like telling me to try all the different golf clubs to find out what's best for me. I'm not a good golfer, could swing them all and still not know much. One might "feel" better to me, but that is not a good sign that it will actually work better. Once someone is a good caster, trying different rods starts to make sense. We develop "feel" preferences, some like slow, some like fast. That said, any of the rods would work just fine and any good caster should be able to quickly adjust their cast to accommodate different rods and get the same results.
An analogy I like to use is this... Tiger Woods and I trade golf clubs for a game. His score will stay about the same, mine will probably suffer as I don't know how to adjust to different clubs very well.
Bruce
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[GH] Bruce,
I've given thought to the idea of handing a Master Candidate a grossly mismatched outfit and seeing how long it would take him (if ever) to adjust his cast to it. This would help separate the sheep from the goats !
Gordy
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Hi Gordy,
Loading a static spring (fly rod) that is not held in the hand is quite different to one that is held in the hand e.g. Bow & Arrow Cast as I think you have found out.
Bruce and others have occasionally referred to the acceleration of a fly rod being constant; to achieve that you need to apply a constant force. Whether or not you agree with that is another matter but all casters would have to agree that ideally acceleration occurs to speed up the rod tip throughout the casting stroke (however you may choose to define casting stroke). A bent rod acting as a spring applies maximum force immediately the line is released and thereafter the force diminishes as the spring straightens which is close to the opposite application of force that produces a nice cast. And that’s why it does not work.
Best regards,
Ally Gowans
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[GH] Ally. Very simple explanation which helps me a great deal. Provides the HOW and WHY to the observed result.
Gordy
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From Jim Rainey:
Gordy: Referring to your observation “That bump can be straightened out partially or completely depending upon the tension of the forward traveling loop.”
If the caster is shooting line, will there be less tension on the forward traveling loop and hence less straightening of the bump?
Thanks. Jim
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[GH] Jim,
Seems to me that there would be less tension between the rod tip and the loop when shooting line at any one point in time. However less it would be, it would exist for a longer time, since the loop would be traveling a greater distance and would take longer to unroll.
That fit with what I noted when casting..............
After you sent that message, I went out and made some casts to see if I could give you a better answer. Not easy without video. I got the impression, however, that the "counterflex bump" was still almost eliminated when I shot line, but it took longer.
Much better to make those casts with and without shooting line with a limber, soft action rod so that counterflex would be magnified .... and document the findings with video.
Someone may have already done that.
Gordy
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