Max tip velocity

Walter & Group........

From Bruce Richards on max tip velocity :

G.
 ******There has been some arguement re: exactly where max tip velocity
 occurs, but it is certainly very close to RSP if not at RSP.

The thought
 is that as velocity increases, acceleration decreases so when velocity is
 max, acceleration is zero, of course.

 Without a line attached to the tip
 max velocity would certainly occur at RSP, but with the line holding the
 tip back, it is possible that max velocity could be reached a small
 fraction of a second before RSP. I've talked to Noel about this and he
 agrees.

But there is no functional reason to want to confirm this, it has
 no impact on casting or instruction, but is a matter of small scientific
 interest. Someday we may work on that, but only when we have time to delve
 into minor casting oddities...

Bruce

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From Paul Arden :-

Is it possible to pick up 30' of line plus leader using only translation ?

 

 

Hi Gordy,

hand casting can be translation only and I'm sure you can pick up  30ft this way.

Nothing wrong with teaching the concept of translation to a beginner, it just depends on the student and the method you use.

Incidentally when you consider rotation and translation it is normally translation that causes the tail.

Cheers, Paul

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

Paul...

A point I hadn't considered.  I had tried it with a fly rod and simply couldn't do it.

 

Of course, Lefty feels that pushing forward with the hand at the end of the stroke causes a tail, ie. "translation".  I agee.  Problem is that I don't see that this is the way most of our students do it.

 

Gordy

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

From Eric Cook :-

 

 Gordy,

I too was ready to let the dead horse be until I read the statement from Dennis; "If there is rotation during translation it’s not translation". After reading that, I became quite uncomfortable and could barely sleep last night, thinking of my rebuttal that I would send you this morning. I was prepared to look at it from the perspective of line speed at the tip and how it is the sum of the rotational + linear(translation) + haul speeds .......charts......graphs......equations........blah,blah......etc. However, a few pressing matters at work delayed my response long enough to see Troy had already addressed it and with your response, I am back in my peaceful place.

While I am here, I guess I might as well take a good swat at that poor horse. I have taught with the terms rotation and translation to a certain degree with more advanced students. Particularly with students that want to increase distance, I have demonstrated how different movements of the rod, arm, body, etc. are "accelerators" (maybe not the best term) and how they are cumulative with respect to line speed. I explain what can be expected, in simplified quantities, from the different rotational and translatory type movements. I am not a fan of using a translation only phase to pull in slack but rather to get a "running start" on the big accelerator (rotation). I also believe that a translation only phase (coupled with a fairly loose grip and plenty of tension in the line) can improve/correct minor tracking errors. It seems (to me) that it aligns the cast the in the same manner as a weather vane or wind sock aligns with the wind.


Now, as for the question about the haul tightening the loop size. I know that I am risking the start of a riot by jumping into physics at the onset of this topic, but here it goes. I believe that the force vector created by the haul would always be collinear with the line that is outside the rod tip. The resultant force vector of the entire system (haul, rod arm motion) would be brought down closer to the SLP that we desire. All this is saying that more casting energy is being directed towards the target for a straighter fly leg of the loop.

Also, with a haul there is less of a need to generate the necessary line speed with the rod hand. Therefore, the result is less momentum in the rod, enabling a more complete stop to keep from opening the loop on the rod leg.

If I had to say which is more of a factor in loop size reduction from the haul and/or what is my short answer, it would be reducing rod momentum enables a more complete stop. For that matter, the first answer would probably do nothing more than start an argument amongst casting geeks and would definitely confuse a student.


Eric
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Eric.

 

I agree. 

 

After all is said and done, however, I still see that a straight line path of the rod tip is needed for a tight loop, throughout and at the conclusion of the cast, with just sufficient convexity at the very end to unload just below the oncoming line so you don't have the line crashing into the rod .

 

All casting arm and line arm movements must combine to achieve this.  To that end, I agree that the haul can contribute to the size of the loop.

 

As far as the length of the haul is concerned, we must note that some of our world class champion casters have razor sharp loops with maximum haul length.

 

A, "complete stop" can help avoid the opening of a loop, too.  In the real world of casting, this is rapid deceleration ("negative acceleration") rather than a, "brick wall" stop.  The latter ruins the cast by yielding uncontrolled waves in the line.

 

 As an engineer / physicist and a casting instructor, you obviously wear two hats !  Same with Troy, Noel and Walter.  We love you guys.  You have the inate capacity to confuse us mere mortals while at the same time helping to educate us.

 

Gordy

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~``