Hand Path/Tip Path

[Frank LoPresti]

Is it " Why oh why does it have to be so complicated?"

What complicates it, is theory waving old boy !

[Stoatstail50]

Beats me Frank...I'm only a dumb CI.. all this complex arguing stuff does my head in...

[Frank LoPresti]

Hurts my head when people wave theories around and then you have to think about what's missing. Once you figure how it all fits the theory waving comes a bit easier to deal with. Funny thing of it is, for each theory I have heard as to how translation effects tip path, and loop formation, once it's be "decoded," and answered, the answer is ignored or largely unacknowledged, and before you know it, another theory is waved once again.

I suspect there can't be many more theories than I have already heard and I have heard them all here on SL, as to how translation has a direct bearing tip path as it goes to loop formation. I suspect this one is the last one though, and the one I'm not giving away the answer to either, unless someone can do it other than me. And it ain't rocket science either. It's more about reasoning than anything else. That's a big hint too Mark !

Frank

[Stoatstail50]

Well reasoning doesnt seem to be a strong point in here Frank but lets have a go....

In your drawing the "distance of tip travel" for the top drawing is four columns and the "distance of tip travel" in the bottom drawing is six columns. I think we would both agree that this is as a result of translation or "lengthening the arc" as you prefer to call it.

We can agree this too....

In a practical working sense it lengthens the ability of the caster to apply angular acceleration over a longer distance no more no less.

Obviously if you accelerate something over a longer distance it will be going faster than something accelerated at the same rate over a shorter distance.

This we can explain in a more complicated way by using the simple fact, not a theory, that Work, measured in Joules, is calculated by multiplying Force times Distance. Where the distance of tip travel is increased by two columns from four to six as in your drawing, the work done by the second cast on the line is 50% greater than the first. Joules also happen to be the Si unit of energy, so the kinetic energy of the line will be 50% greater in the second cast than in the first too. In simple terms this means that the line velocity will be greater, which is clearly much the same as we have said above.

Anyway...lets have a look at tip paths....

If the rod just translates, then the tip path and the hand path are the same, if the rod just rotates then the hand path is zero and the tip follows the arc of the circle for which the rod is its radius.
So, what happens if we combine the two ? Because the arc is the same in both cases, the effect of translation is to move the instant point of rotation below the rod butt and the tip will follow the arc of a circle with a greater radius than that of the rod. Without wishing to be too technical here this means that the tip path will be "less curved" and so, net, the force vectors will be "flatter" for want of a better term.

Aha...I hear you say Frank....but what happens if we apply a load at the tip and a force at the butt and the rod bends ?

If all we do is rotate then for most casts the tip path would be like a shallow spoon shape turned bowl up on a table. The tip will dip a little as the load is first applied and then it will momentarily rise again, it will dip as it follows the path caused by rotating an increasing bend up to the maximum bend and then rise again as it it unloads either due to a stop or a change in the pull angle.

We compensate for these weird tip paths by managing the hand path and many hand paths are the mirror opposite of the tip path I have just described.

If all you have is rotation then your hand path is zero distance, in order for the hand path to be more than zero distance you have to add translation and that is how translation effects tip path with respect to loop formation.

[Frank LoPresti]

If all you have is rotation then your hand path is zero distance, in order for the hand path to be more than zero distance you have to add translation and that is how translation effects tip path with respect to loop formation.

Not entirely correct. But your getting closer.

[Frank LoPresti]

If all we do is rotate then for most casts the tip path would be like a shallow spoon shape turned bowl up on a table. The tip will dip a little as the load is first applied and then it will momentarily rise again, it will dip as it follows the path caused by rotating an increasing bend up to the maximum bend and then rise again as it it unloads either due to a stop or a change in the pull angle.

We compensate for this weird tip path by managing the hand path and many hand paths are the mirror opposite of the tip path I have just described.

Ahhhh, no and no and add 8 more to that number for these two paragraphs.

[Frank LoPresti]

Mark,

BTW. Lasse and Ben seem to be really well versed in roll casting videos and techniques. I'm guessing they would be more than willing to answer any questions you might have in regard to hand path, tip path, and loop formation.

Best,

Frank

[Stoatstail50]

Thanks....I'll be sure to ask them.

[Frank LoPresti]

If all we do is rotate for most casts the tip path would be like a shallow spoon shape turned up bowl on a table.

Hi Mark,

I don't know if your trying out a new version or this is just your understanding as it goes to tip path. I like the spoon analogy but you have the spoon wrong side up. One of the reasons I'm hesitant to go beyond that is that every time I attempt to explain something in a straightforward manner invariably someone comes along an says yeah that's nice Frank but what if ? Well there are a lot more "what ifs," out there than there are actual "whats," as to what essentially goes to what in respect to casting mechanics. I suspect most of what we know we've know for a long time now aside from some of the technical analysis with respect to data and even a lot of that has been around for a while.

So when someone jumps in and says yeah but hey what about Suoerimposition or what about the "Frank Machine," or what about Grundes model or Bill's model, or the TLT model or what about applying a smaller force over a longer distance, as opposed to applying that force over a shorter distance, it's easy to lose sight of the basics. Basics are boring, they lack color they are devoid of color. That's what I know.

Think about this though. Absent translation a tight loop is the still the result of line speed and it would "seem," that the effect of the tip path as a result of tip speed would be the determining factor in loop formation.

Then add translational distance of lets say 2 feet to that tip path and the loop then suddenly gets tighter ? Tighter than what ? As a result of adding translation force over a longer distance ?

Consider that the 170 style produces a wide deformity in loop as seen in Pauls stroke or anyone else who uses that method. Lots of translation but the loop is wide and some have speculated by as much as 3-6 feet wide. Then take a more compact stroke ( less translation, far less arc), like Rajeffs style and you end up with a tighter loop shape.

That and the fact that most every caster I know would tell you that super tight loops are not the best loops for throwing distance and yet you have those that appear to want to believe that somehow adding translation to the stroke has a direct bearing on tip path as it goes to loop formation.

All I'm saying Mark is that you could add a lot of what if's to this post, but I'm afraid the only question that really needs to be addressed now comes down to this. If you agree with Gordy as do I, that angular acceleration is the dominant force as it goes to tip path and loop formation, what indirect bearing does translation have on tip path as it goes to loop formation. What if it doesn't have any bearing on it ? So ?

Frank

[Magnus]

What if you add a haul Frank?

[Marc LaMouche]

[Frank LoPresti]

What if you add a haul Frank?

Why not just keep adding "what ifs," until the basic structure of the cast is based entirely around " what ifs," as if adding more "what ifs," would alter the fundamental structure of the cast. What if they don't ?

Your kinda borrowing from Hans Vaihinger and his Philosophy of "As IF", as if the 'what ifs," create some newer kind of model for fly casting which they do not.

[Stoatstail50]

Here is another bit of reasoning Frank....

Lets say that you are right and that the hand path doesn't have any effect on the tip path with respect to loop formation.

If this is true then I could use any wobbly old hand path I like to add length to my arc and, on the basis that it has no effect, it wouldn't change the tip path one iota with respect to loop formation.

Whaddya think...?

[andy_with_a_rod]

Here is another bit of reasoning Frank....

Lets say that you are right and that the hand path doesn't have any effect on the tip path with respect to loop formation.

If this is true then I could use any wobbly old hand path I like to add length to my arc and, on the basis that it has no effect, it wouldn't change the tip path one iota with respect to loop formation.

Whaddya think...?

Guys, specifically frank, which of these two hand paths with give the caster a greater chance of a higher line speed and greater loop control, which will lead to a best distance of cast?

[Magnus]

Frank

I'm happy to look at the variables which contribute to tip path. I'm not happy that you seem to want to dumb it down to one variable badly described.

Oh and being compared to Vaihinger is no insult