The Stop

[Lou Bruno]

Paul,
Great videos...with the Hard Stop, I find it difficult to detect any noticeable squeeze. Are you forcibly stopping the rod without a squeeze of your casting hand, does it matter?
Lou

[Paul Arden]

Well it's obviously not a hard stop but a hauling stop! What it is is my conventional stop without pull-back. That's why I found Gordy's comments particularly interesting. Once again it makes me aware that I'm not always doing what I think I am! No doubt this is where lots of confusion has originated in casting and it's only through analysis can we be proven right or wrong.

Cheers, Paul

[Merlin]

Here is the mail in question, Paul.

A little bit of explanations first: Gordy asked me to check what a "pure" self deceleration would give using the recorded speed and angle values of a 170 cast made by Paul, and the tackle characteristics (rod, carry). This is the subject of the mail I sent to a few people this morning:

"The following graphics illustrate an attempt to simulate Paul’s stopless cast with the 1D casting model. The input is made of an exponential plus a quadratic function. When the acceleration ceases, the rod unloads abruptly with a strong deceleration rate (10 000 deg/s2). The model is a pure “free ride”, meaning that the rod is left on its own at the end of acceleration phase. Reality is not such caricature; in fact there is a blend of self deceleration and driven deceleration, it depends on how strong the hold of the handle is. Typically, the self deceleration generates rebounds in speed: the rod starts rotating forward on its own after stopping periods, and drives the hand of the caster who is relaxing is grip to dampen the kinetic energy remaining in the rod tip. A driven deceleration creates a neat stop without rod rebound. Any rebound is a relic of self deceleration. If the “blend” of deceleration types is properly tuned, the rebound occurs very close to zero rotation speed. The rebound timing and its intensity depend on the carry (weight) of the cast. A higher carry delays the rebound phase and allows the rotation speed to reach zero without assistance from the caster (the driven part of deceleration). This is typical of a distance 170 cast. Very little carry does not generate a significant self deceleration, and the caster has to drive the stop of the rod butt. The rebound is minimal, if any. In practice, in a 170 cast, the caster does not allow the rod to rotate until it touches water or ground, so at some stage, he stops the rod more or less softly. This is what contributes to rebound reduction (blue curve), through the retaining action of the hand holding the rod. For purists, the “stopless” cast is not exactly devoid of stop, but the “stopless” character refers to the early unloading of the rod, which is left to the rod and not influenced by caster’s action (hence his feel of non stopping the rod).

The conclusion of this first investigation is that the deceleration model (which is 100% driven to mimic records) should integrate both type of decelerations: the self one, relevant of the “stopless” style, and the driven one, in order to better simulate reality. We do not squeeze the handle the same for a short or a long cast, and we can benefit of the self deceleration mechanism when it is active (which needs a minimum weight of carry, its amplitude increases with the mass of carry), and this is just the “stopless” style, even if the name is not technically correct. It is a “mostly non driven decelerated" cast. A short cast is a “mostly driven decelerated” cast. They both are “driven accelerated”.

Another outcome is that rebounds, often visible at the end of a cast, are a mark of self deceleration. Gordy’s analysis has shown us that rebound can occur earlier, particularly in a 170 cast. Again, I am very impressed by Paul’s ability to take advantage of the SDM in his long casts."

Paul rot speed.JPG (40.13 KiB) Viewed 5436 times

Paul rot angle.JPG (34.82 KiB) Viewed 5436 times

I could add that rod design has an effect on self deceleration, butt action rods decelerate their butt more easily than tip action ones.

Merlin

[gordonjudd]

Is the plot for the pulled-back cast available?

Merlin,
It was shown back at post #88 #88, but here it is again. Let me know if you would like to get an Excel listing of the data.

Gordy

[Paul Arden]

Thanks Merlin, there is a lot in there to take in.

Would I be right in saying that one reason my casting arc is smaller with the HT10 compared to HT6 is smaller when casting a MED5 is because the SDM happens quicker and therefore extending the arc does nothing except pull the bottom leg down?

Many thanks,
Paul

[Merlin]

It makes sense Paul, it is likely that the HT10 is faster than the HT6 for the same carry. You may also have to shorten the arc to compensate for a slightly higher and more domed tip path. That brings up back to the discussion of the best rod for a given task, which depends highly on the caster himself.

Merlin

[Lou Bruno]

Thanks Gordy. Quick question, would it be self-deceleration mechanism or unloading as the force moves away from the angle of the flyline? And can you let us know what thoughts the results of this experiment lead to?

Very many thanks,
Paul

What's the overall conclusion...I'm not really sure, to be honest. There are different techniques, the one we choose depends on the circumstances?
Thanks

[Lou Bruno]

When does the rod tip make its first stop? Are there any diagrams that show the following rod tip positions?
RSP 1 (1st rod straight position)
RSP 2 (2nd rod straight position)
RSP 3 (3rd rod straight position)
MCP (max counterflex position)
MRP (max rebound position)

Lou

[Paul Arden]

That's an interesting theoretical question, Lou! I would assume the first stop (instantaneous) is at MCF1 when the tip reverses direction. And then at every CF position until it finally comes to rest. If it's a fibreglass rod this will take some time. If it's a Hot Torpedo then it will be much quicker with less wobbles

Cheers, Paul

[Lou Bruno]

Paul
Being that a change of direction requires a stop...all the RSPs, do not produce a stop?

Lou