Rod tracking and accuracy

[Merlin]

I guess Paul decided to drop the thread on the new rod supposed to be 4 times more accurate than its predecessor. One can use any rod and get accuracy from training, even if the tool is imperfect, the caster can accommodate with practice. However, one can detect a better tool quickly when he tests it, and that was obvious to me when I fished my first rod with specific under layers some 15 years ago. At least this is my experience.

A technical issue is to make the rod bend in a single plane. There are two possible tests to confirm that. A static one, using some mass at rod tip and checking whether or not the tip stays in the vertical plane he met before adding the mass. Out of plane bending shows there is a stiffness dissymmetry in the shaft. By construction, graphite rods are asymmetrical. This can be checked by calculus when knowing the number of turns of prepreg used by the rodmaker for each section. When the flexion is out of plane the rod shaft is twisted and there is some structural risk for the shaft, especially if it has no hoop fibers.

The second test is the vibration of the tip with a clamped handle. It can become strange as the tip whirls in various figures sideways (pluck it down gently and let it go). This shows a problem which is known to be located into the butt section of the rod (mainly, by a large amount). Again it is an asymmetry issue and if it happens it can be solved by rotating the butt for some angle (e.g. 30 degrees). It is of course better to make such a test before mounting the hardware on the butt section (reel seat).

Both problems are related to the spine of sections. A smart solution is to make a “spine neutral” rod by staggering spines of the various sections instead of aligning them. So the process is to find the spines, stagger them (e.g. turn sections by 90 deg or 120 deg for a multipiece rod), and check the position of the butt for whirling. Once this is done you can put guides on the top or on the bottom.

The rod should track straight and it is then up to the caster to take benefit for accuracy casting (if he needs it). That assumes that sections are rather straight and not twisted by too large a pressure during the rolling process.

Merlin

[Torsten]

Hi Merlin, I don't remember any thread was ever dropped (?) -> it's now in the tackle section.

[Merlin]

Hi Torsten

Funny, I checked the tackle section this morning but did not see the change.

Merlin

[VGB]

Hi Daniel

This shows a problem which is known to be located into the butt section of the rod (mainly, by a large amount). Again it is an asymmetry issue and if it happens it can be solved by rotating the butt for some angle (e.g. 30 degrees). It is of course better to make such a test before mounting the hardware on the butt section (reel seat).

I can remove 11 inches from the butt section of my travel rod with no discernible difference in fishing range accuracy. Many small stream anglers take the butt section off the rod of 4 piece rods when there is insufficient room to make the cast, again without a noticeable difference in accuracy. It is easy to try this experiment, the only issue is holding on to rods with thin sections.

regards

Vince

[VGB]

Funny, I checked the tackle section this morning but did not see the change.

The thread has been touring, it went to the video section first and has bought tickets to visit other parts of the board during the next week or so

[Merlin]

Hi Vince

That means that the butt section had no significant spine effect. The whirling is relatively rare, only one of my (about 20) rods does show such problem.

Merlin

[Torsten]

Hi Merlin,

Gordy observed the whirling for a free swinging rod, after he attached a weight (with a mass of 28g) it disappeared - at least this was my impression from the text in the archive. Maybe someone could repeat this experiment.

Greetings,
Torsten

[VGB]

Hi Daniel

Most of rods are not straight when assembled, I suspect that if I stuck them in the chuck of my lathe they would twirl. It is very difficult to get even a single section laser straight to sand grips, I can see that it would be easy to introduce errors over a full rod length.

Regards

Vince

[Torsten]

Hi,

I tried another experiment, tied the rod top guide with some mono @ the ground and did then a load/unload test, bending the rod. If spine would be an issue the tip would kick to the left or right, when I'm loading/unloading the rod. But I've not observed this, tip tracked exactly straight - tried all sorts of rod orientations. Test object was a #7 build on a Quickline blank.

Greetings,
Torsten

[Graeme H]

I tried another experiment, tied the rod top guide with some mono @ the ground and did then a load/unload test, bending the rod.

…

Thanks Torsten. That should do it.

Cheers, Graeme