The Board

Gordy How are you calculating the elastic energy in the rod? Is it based on the perpendicular tip deflection and the spring constant of the rod (i.e. k1*x.^2/2 + k3*x.^4/4) or on the curved shape of the rod along with its variable stiffness characteristics? For the 2D casting model I map rod charact...

Hi Paul Below you can find the rod elastic energy history along the timing of the haul. Peak elastic energy is obtained when the haul is made early, PHV occurring 25 ms before MAV. elastic energy and haul timing.JPG To avoid a tailing issue it is recommended to have PHV something like 50 ms after MA...

Even better, I would think that matching the max haul acceleration with the maximum tip speed of the rod tip so you would apply the peak force from the haul over a maximum distance would make sense from a work energy standpoint. Merlin might have an idea of how the tension added with the haul hand ...

Bernd

Here is a table with a first set of runs. In terms of energy efficiency, there is little difference, the main one comes from the maximum torque which has to be used by the caster. It is much smaller in case of haul (e.g. 20% less). Merlin

Thanks a lot Gordy for reminding us important considerations for the haul.

Merlin

Thanks Bernd, that helps me and I shall define a few scenarios along your descriptions.
Maybe I shall consider a different carry at start in order to have the same line length for the launch, with or without a haul.

Merlin

Good point Bernd

I need the data analysis of Paul's cast to get a better idea, I do not have all the original data.

Merlin

Ok Bernd, let’s specify the comparison basics: • The line length out of guides is given at start (e.g. 10 m), the line length down to the hand line is something like 3.5 m at start and we pull some line within 300 ms (haul duration). Haul length is then define by max haul speed and I take 5 m/s here...

Hi Mike Nice video indeed. The broomstick cast lacks speed generated by rod (spring) since you cannot cast fast enough for the “rod” to bend, it is just out of human capabilities at that level (you would need several thousands of degrees per second). So the haul is necessary to get suitable line spe...

Hi Bernd I see what you mean. Maybe Gordy could use the data of Paul’s cast record to split the rod hand and line hand contributions to line haul speed understood as the speed measured by reference to the stripping guide. Not an easy task since all is not in the same plane (line hand, rod hand). The...