[SPAM] Shane's critique of past message on casting mechanics

 

Walter & Group :

 

Shane:

 

All this is becoming more clear.

 

We must also (as you stated in your message) realize that there has to be a change in parameters based upon the fact that the rod tip isn't moving alone.....but is doing so against the inertia of the fly line.

 

Your critique of your own statements shows that you are giving this material a lot of good thought !

 

Gordy

 

 

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Gordy,

 

After tossing the following statement in the mix, and thinking it through further, I anticipate that what I said below might be controversial. So if no one else has, let me be the first to jump on it! Certainly it paints an incomplete picture.

 

So how fast the rod is loaded is ultimately not relevant to how deeply it is loaded. We could bend [the rod] back by slowly pulling the tip and holding it (like a bow and arrow cast). When we are casting normally, though, it just so happens that we bend the rod by accelerating the rod butt and the tip against the inertia of the line. But like an archery bow, it is not how fast we pull the bow back, just how deeply we pull it. [how fast we do it really relates to the velocity of the rod tip imparted by the casting stroke. ]

 

 First lets look at a simple spring with a mass attached, traveling in two dimensions. The system response of the spring when it is released depends on the mass, stiffness of the spring, and how far we deflect the spring from its resting point, but not how long it took or even how jerkily we did it. In other words, the potential energy stored in the loaded rod could have built up slowly or quickly; regardless,  how it is released will be the same. So in a simplistic view, what happens to the rod when it unloads doesn't depend on how it was loaded. Additionally, the effect of the rod unloading affects the line after the rod butt is stopped and is reflected in how the line turns over and the lower [rod] leg of the loop.

 

But how we load the rod is important in the velocity and path the rod tip travels during the loading phase up to the stop. That is the rod must be loaded smoothly [constant rate of acceleration] to get a smooth nearly straight path of the rod tip. This effects the line before the stop and this is reflected in the upper leg of the loop.  

 

Certainly this oversimplifies or ignores other factors of the cast such as rod orientation, but it I think it provides insight into certain aspects of the cast. Although continuous parts of the casting, by breaking it down in the loading and unloading phases, helps understand why we want to load the rod smoothly and deeply not fast and hard [to use imprecise terms]. It also helps me visualize better what affects the formation of the upper and lower legs of the loop as Bruce had described it in his casting analysis workshops.

 

Shane