OK, so my last comments in this thread: a rod can start unloading before the end of acceleration, it is a matter of a few 1/100 seconds and nobody cares but me. I could not imagine that all I said is scrutinized from the beginning. I promise not to do the same with your posts. Now I will have to us...

Vince Models are clearly a replica rather than an extremely accurate desciption of what is happening in an overhead cast. However, they have been tested along recorded casts and give a fairly good estimate of reality sometimes, and not such a good one sometimes too which I mentionned a few times. F...

Walter We are switching from model world to real world and vice versa. Mark was talking about DH rod real world and likely some form of Spey casting. We cannot model that for the time being. We can describe the general conditions affecting real world motion of complex cast, like movîg around the ro...

Walter, There is always air drag, on the rod and on the line: you start by accelerating slowly against inertia and then the rod stays in a nearly constant deflection as the pace becomes nearly constant, you can change the pace slowly and describe circles, figure eight or whatever; the rod will rema...

Mark Let me clarify some points. The “oscillations” mentioned and illustrated by James correspond to a very specific case which you can’t observe in practice. To get these conditions you need a rod that would be 100 times stiffer that what you are using today. If you would like to see a rod unloadi...

I'm with you Mark, I think the actual conditions are such that they do not correspond to all the variety of situations we can imagine with a model. Experience has told rod designers which stiffness to chose for which line and despite the uncertainty around this fit, generally speaking, there is a s...

James You are on the good track. Now you have to vary the inputs (brick mass, weight mass, and spring stiffness) to come to a situation close to what I described, something looking like a cast. I can guide you if you give me the values you are using. At this time, your spring stiffness is too high ...

Gents, A few information about the models: losses are in (but negligible for comparison purposes as Vince said), the lever effect is in also. Vince: the broomstick is represented by the red lines in the Lincast model, you can find circumstances where the broomstick is better than the flexible lever...

Sorry for the confusion Gordy, We were talking about the no spring case and Marc was thinking about achieving the same speed than with a spring by introducing more energy at some moment. Introducing Aitor experiment model is also somehow confusing because it is not exactly the simulation of a cast,...

The question is how to do that, Marc Let's imagine I keep the same casting arc, the "car" will produce 7.7 J; 3.6 J in the line and 3.7 J in rod kinetic energy. You would have to reduce the "casting time" by 25% (strong arm). The main problem is you have to more than double the ...

OK, so in my world, the extra 8% it takes to get to velocity x is not all stored in the spring and the spring doesn't deliver all of whats left to the brick. Whereas in your world there is more than 8% energy stored in the spring...how much more energy is there in the spring and where did it come f...