A Loaded Question

[Merlin]

Hi George

It is difficult to define a criteria corresponding to maximum load for a rod. MCL might not be the best, I think that "maximum elastic energy" in the rod is a better reference. Generally speaking it takes place very slightly before MCL (a few milliseconds) and this comes from the dynamic character of "load". Static load is not adequate for a comparison.

As the rod unloads part of its energy is shifting towards the tip, which is showned by Tobias in his video. The butt unloads first followed by the middle of the rod and then by the tip at the end of unloading.

Merlin

PS for James: a fly line can accelerate in vacuum but we are unable to make a video, and it will not veer in any condition. A pity Torsten did not publish his work on this point.

[Merlin]

Hi again

The rod is starting to unload just after the caster decelerates the butt rotation and can pass RSP before the final stop. All depends on a complex relationship between rod characteristics (loaded frequency) and caster’s input. The slower the tackle is the later unloading takes place.

Merlin

[Paul Arden]

Hi Merlin,

This question actually goes back 20 years. So the rod will begin to unload when the caster decelerates the butt. But the question relates to the rod angles in post 1. The further past the perpendicular we go with the rod butt, the question is has the rod begun unloading? If it has begun unloading (which I don’t know), can we still accelerate the angular change? In other words is it possible to accelerate an unloading rod?

Thanks,
Paul

[Merlin]

Hi Paul

The loading of the rod corresponds to the rotation acceleration phase of the caster. We may say that at the end of that acceleration (we are then at maximum rotation speed), the butt of the rod is approximately vertical.

The rod responds with some lag then the maximum load takes place at some positive angle (e.g. some 25 degrees forward max), MCL coming even later (up to 45 degrees forward max, these are order of magnitude).

Since the caster is in the deceleration phase of rotation after the vertical position is achieved, there is no possibility to reaccelerate soon. I can see two possible mechanisms: you use a thrust to counteract the rebound of the rod which is late in the cast, or you use a properly timed haul to act on the unloading of the rod, delaying it somehow.

Merlin

[James9118]

We may say that at the end of that acceleration (we are then at maximum rotation speed), the butt of the rod is approximately vertical.

Since the caster is in the deceleration phase of rotation after the vertical position is achieved, there is no possibility to reaccelerate soon.

Merlin

Hi Daniel,

I'd say that these assumptions are on decidedly shaky ground - Paul's description of his distance cast indicates that he want to 'hit it' when the rod butt has passed the vertical. For my own (distance) cast, my max force input comes when I'm hauling both hands apart, i.e. thrusting the rod up and forwards (in the direction of the cast).

James.

[Merlin]

Hi James

By thrusting forward you delay rod unloading, moving forward a greater force which gives more energy to the line. You then use translation acceleration, little comes from rotation at that moment.

Merlin

[Paul Arden]

James is correct Daniel. On the backcast I wait until the rod butt has passed the perpendicular or indeed even later before I hit it. That is rotation from the elbow and to a lesser extent wrist. All distance casters know of the error of hitting it too early on the forward cast, once again acceleration should occur after the perpendicular, and I use that as a cue. For me that is rotation with or without thrust. I find it critical that the force is applied angularly to the rod butt at this point, as opposed to straight (which I think is a very common mistake).

Of course that may not be what is really happening!

Cheers, Paul

[Merlin]

Paul

What do you mean exactly by "hitting" the rod. Is it what James is describing? If so I cannot find it on a record of one of your competition casts. You keep on rotating some joints to allow your hand to move forward and upwards, and the translation of your hand does not show a particular change as the vertical position has been achieved.

Has "hitting" something to do with maximum rotation speed which happens to take place as the rod butt is close to vertical position?

Merlin

[George C]

Translational acceleration seems undervalued and under discussed.
I wonder how much of that contributes to the feeling of a 'hit'.
These pictures show quite a lot of translation is occurring at the same time as rotation.
Rod vertical also seems to occur quite late (note arm extension) for it to represent the start of the 'hit'.
Note also the position of the hauling hand at rod vertical......although lag in rod response may affect when we perceive rod vertical????
Perhaps Paul has changed things, like haul timing, since this video was made?

[George C]

If you enlarge the images above you can see Paul’s hauling hand better. I missed this and now see his haul is later than I suggested. Apologies.
G