wrist based rotation

[Mangrove Cuckoo]

I personally believe that the “hit” occurs as the rod is unloading with such a stroke timing. If you don’t hit it then it’s still going to unload. It’s just that we are adding to the rod unloading and what better way than with a flop?

Paul

The hit is part of the loading of the rod, even if it is late in time, the rod is not already unloading as you hit. Beware that at the same moment the haul is delaying the unloading of the rod, so you may interpret that delay as a wrist effect and not as a haul effect. The question will remain unresolved as long as we cannot follow the rotation of limbs for a recorded cast. I hope John’s work will help in that field.

Merlin

That touches upon a question of mine...

If the "hit" is an impulse applied to the rod, is the haul an impulse applied to the line?

The rod bends and the line stretches, but it feels (sorry!) more like the haul smoothes more than shocks.

No?

[Paul Arden]

The hit is part of the loading of the rod, even if it is late in time, the rod is not already unloading as you hit. Beware that at the same moment the haul is delaying the unloading of the rod, so you may interpret that delay as a wrist effect and not as a haul effect.

I don’t know. It’s not just me delaying the hit until post butt perpendicular. In the same way that while the haul will be delaying unload, the rod is still unloading. We know that because the rod can pass RSP during the haul (but mostly RSP occurs around the finish of the haul).

Wife is with me tomorrow. I’ll try to shoot some video calling out the hit. I’ll also make some video of the rod releasing out my grasp at the time.

Cheers, Paul

[Merlin]

Hi all,

Here is the only data I have about respective rotation speed of joints.

Rod budget FC BC.JPG (35.1 KiB) Viewed 466 times

It was provided to me by Noel by 2007. You can notice the particular wrist speed history during the FC and BC, the caster opening the wrist arc before going to max speed. The relative amplitude of speeds varies between FC and BC. The wrist is not the larger rotation speed provider, it is the elbow. The use of shoulder is different in between casts.

Interesting, isn’t it?

Merlin

[John Waters]

Hi all,

Here is the only data I have about respective rotation speed of joints.
Rod budget FC BC.JPG
It was provided to me by Noel by 2007. You can notice the particular wrist speed history during the FC and BC, the caster opening the wrist arc before going to max speed. The relative amplitude of speeds varies between FC and BC. The wrist is not the larger rotation speed provider, it is the elbow. The use of shoulder is different in between casts.

Interesting, isn’t it?

Merlin

Hi Daniel,

I had not seen that, thanks for posting.

John

[Bianchetti Ivan]

Usually in these things I try to be practical by admitting my ignorance of how to use the kinetic chain efficiently, and I do this reasoning, take a hammer and hammer a nail, if you use your wrist in the end you will probably get the nail wrong, if the wrist arrives lying flat, the nail will probably go in completely.

[Bernd Ziesche]

Hi Merlin,
Thanks for sharing that fine graph.
What means wrist?
Is it the wrist rotating about an external piviting point or is it the rod hand rotating wrist based?
When I talk about wrist based rotation, I see the wrist as a piviting point and my rod hand makes the rotational movement.
I yet dont understand how or why my rod hand would differ from the butt section. Impossible, I think. Unless I add a very open hand (fingers).
Regards
Bernd

[Merlin]

It is wrist based rotation, Bernd

Merlin

[gordonjudd]

It is wrist based rotation, Bernd

Bernd,
And it would be measured by taking the difference between the angular velocity of the rod butt and the angular velocity of the forearm using two MEMS sensors.

Similarly the angular velocity of the elbow would be determined by computing the difference between angular velocity of the forearm and the omega of the upper arm. Getting these joint rotation velocities requires the use of 3 MEMS sensors as is done in the Efly system.

Efly measurement system.jpg (20.97 KiB) Viewed 393 times

Visually you could get an idea of the wrist angular velocity by measuring the change in the angle between the forearm and the rod butt with time.

Gordy

[Bernd Ziesche]

Hi Gordy and thanks Merlin.
Positioning the sensor on the forearm ... how can that refer to wrist based rod hand rotation?
However it explains the results.
Thanks.
B

[Bernd Ziesche]

Hi Merlin, hi Gordy,
It was too late yesterday and I was too tired after a long weekend in Spain. Forget my last post #199 though.
I studied your replies again. Got it now.

The questions are:
Why is there such a difference between the fc and bc?Maybe compensation of slip in the fc, maybe headwind, maybe the caster was used to create extra speed for delivery in general. Many possibilities. I assume we don't know.
What was his purpose?
Did he try to add a powersnap, or did he try to delay rotation best by running out of upper arm.
I am sure I could vary such a graph a lot! No doubt I could make the wrist peak, if I would want to.
Highly variable numbers.
Interesting? Yes. Representive? Yes, for what the caster did in that and only that cast, I think.
Would be great to have someone vary the numbers on purpose and see where the extremes are and what the line does in these.
Regards
Bernd