"As Iron sharpens Iron, so does one man sharpen another"

The below is meant to kick off a discussion on a topic that gets a lot of attention, specifically "sensitivity" as it relates to fishing rods or blanks.

Sometime in 2012, North Fork Composites (our engineers) were approached by a customer that had a very unique requirement - a composite/lightweight portable antenna.

How does a composite antenna relate to sensitivity of a fishing rod? Keep reading.

In 2016 we went public with an invention - a lightweight composite antenna, in order to protect the invention, a number of patents were filed, the ones that I would like to discuss here are patent numbers 9991588 and 10005889, or respectfully titled "Highly conductive fiber reinforced antennas" and "fishing rod with enhanced tactile response"

[www.compositesworld.com]

[patents.google.com]

and

[patents.google.com]

What ensued prior to the filing (and granting) of the patents is countless hours (and I really mean countless) of testing, tuning, measuring, documenting, and re-testing various hypotheses on what makes a good antenna, but more specifically what various terms like frequency, conductivity, sensitivity mean in a real world application.

For the purpose of this discussion, I am defining "sensitivity" as the measurement of vibration along a tube.

We used a process of measuring vibration along a tube, and it involved a source that causes a vibration on one end, and a device that measures that vibration on the other. It can be a speaker that plays a sound at 60hz where the beginning of a tube starts, and a vibrometer that measures the resulting vibration on the other end. (I am using the word tube, as we didn't just do this for blanks, but for antenna elements, which are composite tubes).

I would like to share some of our "takeaways", in hopes that you will find them valuable, in one of the cases, the USPTO agreed that a fishing rod blank which has a metal that has been vapor deposed on a fiber, or a chopped fiber scrim that is also vapor deposed with a metal makes a blank much more "sensitive" according to the definition above.

"In a normal carbon fiber composite, the carbon fiber is well bound to the epoxy matrix. Thus, when vibrational waves travel either up or down the length of the composite, there is a loss of energy as the vibration moves from the high modulus fiber to the low modulus resin, and back and forth as it continues up or down the length of the elongate structure. However, in the case of the nickel-coated carbon fiber, the interior surface of the nickel coating does not adhere in any fashion to the outer surface of the underlying carbon (nickel is a non-carbide former), but the epoxy adheres extremely well to the oxide rich nickel coating exterior surface. This adhesion lends mechanical integrity of the composite, while at the fiber/coating interface, the lack of a bond conserves the mechanical energy to more fully remain in the core fiber as it travels up or down the composite.
The resulting chemical and mechanical discontinuity at the fiber/coating interface allows for more transient energy to be retained within the carbon fiber (i.e., a conservation of energy), while the strong chemical bond of the polymeric matrix to the metal coating assures mechanical integrity of the composite. The result is a composite which retains its characteristic weight, stiffness, and strength, but exhibits increased low frequency vibrational sensitivity down the elongate structure in composite applications." (Taken from paragraph 4 and 5 of the 'Brief Summary of Invention, Patent 10005889)

What Patent 10005889 claims is that by using a fiber that is nickel coated (through a vapor or a chemical deposition) one gets a bump in vibrational sensitivity - but more importantly, we detail how it was done.

"To test for sensitivity and to compare the sensitivity between carbon fiber fishing rods and metal-coated carbon fiber fishing rods such as fishing rod 10, a testing protocol was devised and is depicted in FIG. 2. Multiple tapered tubular structure blanks 28 (i.e., tapered tubular structures 12 as would be used in fishing rods 10) made of uncoated carbon fiber and metal-coated carbon fiber, each in a polymeric matrix made of the same polymer, were made to have substantially identical weight, stiffness, and strength. The proximal end 16 was placed on a vibrometer 30 (a type of accelerometer) and the tip 18 at the distal end 20 was connected to vibration-imparting device 32 that imparts vibrations of various frequency and amplitude to the tip 18. The results of various testing will be described in more detail hereafter with reference to FIGS. 5-7." (which is what I described above)

Once the results were obtained through the process described above (objective - as in anyone can repeat this as described if they follow the process above) 60 people were chosen at random at a University lab, and the results were re-enforced with their "subjective" input (the rods/blanks made with nickel were more vibrationally sensitive than those of regular carbon)

Why am I going into all of this detail?

As a manufacturer that spends thousands of hours on R&D (and hundreds of thousands of dollars annually on R&D) It is difficult for us to stand by and read about TNF/CCF (True Natural Frequency or Common Cents Frequency) as it relates to the "vibrational sensitivity" of a blank.

What you are measuring by going through the TNF/CCF process, is the recovery of a blank, but that TNF number has nothing to do with a blanks vibrational sensitivity. In fact, the author never mentions sensitivity, and the only thing that I can think of, is that is being imparted onto sensitivity because "frequency" is used.

Here are some of those learnings:

1) High modulus of a fiber is not a guarantee of superior sensitivity, there is a correlation, but what really matters is how dense the entire laminate/blank is. You can have a lower modulus fiber, but a denser laminate, and the blank will be more vibrationally sensitive
2) The presence of a fiberglass scrim reduces the vibrational sensitivity of a blank
3) The taper of a blank affects the blanks vibrational sensitivity (bigger diameter of a blank, more vibrational sensitivity)
4) Whether a fiber is sized or not (keep an eye out for future marketing language from someone reading this forum how their fiber is "unsized", I had to go there, I'm not sorry)
5) Adding a metal coating on the fiber, bumps up the vibrational sensitivity, it also adds weight, so how the latter is done is very important
6) Using a scrim material that is metallic significantly increases the vibrational sensitivity (attaching a picture of one of our composite engineers, Al Jackson, holding a piece of nickel scrim that is used in blank construction of one of our product lines) (keep an eye out for "our blanks are made with Nickel Scrim" from the orient soon - sorry, not sorry)

[northforkcomposites.com]

There is a long list - and for a variety of reasons I am not going to go into them here, as those are the fruits of our R&D efforts and are incorporated into our blank production.

For those that are using TNF as a measure of vibrational sensitivity - I am hoping to hear "Why." How do you arrive from a high TNF to "more vibrationally sensitive'?

A fishing rod blank is the combination of four things - the material (fiber) used, the pattern, the mandrel, and the process (what yields a denser laminate)

You can take the exact same pattern, material, process, and just change the mandrel slightly (which changes the inside diameter/hole size/taper) of a blank, and the one with the bigger hole on the inside will be "stiffer", and will have a higher TNF, but , it will not be more vibrationally sensitive than the other pattern.

Happy to answer questions, happy to discuss, and happy to learn.

Best Regards,
Aleks

Great stuff Aleks , somewhat surprised you shared it however .


I know how much Gary despises weight when it comes to rod blanks , he calls it the # 1 enemy of performance so it will be interesting in how he deals with the below . It may come down to the nickel metal coating on the fiber just offering such a big advantage in regards to sensitivity that it outweighs the negative aspect of slightly increased weight.

" Adding a metal coating on the fiber, bumps up the vibrational sensitivity, it also adds weight, so how the latter is done is very important"

Chris,

It's a balancing act for sure - we roll our blanks under 250 psi, the industry standard is about 40psi. This means that we can do get a dense enough laminate with less resin in the material. Less resin means that you can put more of the "good stuff" in the blank (more fiber for strength, a scrim, etc.)

I am not worried about someone trying to use the information above...I wish them luck with the learning curve, and our lawyers are pretty good. It is more for the annoyance of someone saying that they are using a "metallic" fiber in their pre-preg, even though they are not...in case that happens (and it will) you heard it here first :D

Aleks



Edited 1 time(s). Last edit at 01/15/2023 10:49PM by Aleks Maslov.

You're opening line can almost be as sensitive a topic - but rings true nonetheless, I'm grateful for the reminder brother.

You stopped me dead in my tracks with that opener and sent me through a series of links and articles and google searches while standing in the same spot in my basement about to set up and wrap some guides.

I've actually been looking into this a bit myself - measuring sensitivity of blanks/rods. I don't have the same precision tools at my disposal, but was planning to set up something very similar to what you described (similar in the same way a horse and wagon is similar to a Bugatti or Rolls-Royce). I was going to use my phone as an accelerometer and attach it to the blank/rod whole using another device (probably my smart watch) to vibrate against the tip. Although this will be a rather primitive experiment it would at least provide me with some nominal way of comparing rods/blanks ability to transmit vibrations.

What is the blank that you sell with those materials and engineering?

On a somewhat related note, I have gone once before and hope to attend the one in NH this year. [ironsharpensiron.net]

Grace and Peace

Building rods in MA, Building the community around the world



Edited 1 time(s). Last edit at 01/15/2023 10:36PM by El Bolinger.

Oh! I feel big things comings! Thanks for the insight. I love techie stuff. I just finished my 1st NFC blank. Really pleased with it.

Aleks, a great post! This will get the "thinkers, thinking!"

Can't wait read all the responses.

Thanks for sharing some of this research.



Edited 1 time(s). Last edit at 01/17/2023 06:20AM by Chris Catignani.

My former career as a fisheries biologist in some glamorous locations allowed me to fish with some well known anglers. This occurred after I took some graduate level physics courses.I’m convinced that much of the ideas behind rod sensitivity are irrelevant to actual fishing situations. I’ve witnessed a couple of household names in Minnesota accurately interpret every thing going on at their jig in regards to species and size. This was using monofilament with rods that few of us here would ever purchase. Celebrity fishermen are hostage to mass-market sponsor’s rods.

I have a copy of a very rude email from a member of this forum to another that completely missed the paradigm of rod sensitivity. Fishing rods aren’t energized like tuning forks during a bite. The line that subtly pulls downward on the tip also neutralizes that type of vibration. This is basic Newtonian physics. The human reaction time to a touch sensation averages .15 seconds. Not only do rods in fishing situations usually not vibrate in ways where their natural frequency comes into play, but a faster transmission of vibrations from tip to hand is just a tiny fraction of this reaction time. The efficient transmission of force seems more relevant than frequency. Amplitude seems more relevant than natural frequency. Lightness, fiber density, and less buffer by low density things such as resins and guide adhesives seems most helpful. In the end, sensitive hands are more advantageous than a sensitive rod.

Thanks Aleks

Kendall Cikanek Wrote:
-------------------------------------------------------
> My former career as a fisheries biologist in some
> glamorous locations allowed me to fish with some
> well known anglers. This occurred after I took
> some graduate level physics courses.I’m
> convinced that much of the ideas behind rod
> sensitivity are irrelevant to actual fishing
> situations. I’ve witnessed a couple of household
> names in Minnesota accurately interpret every
> thing going on at their jig in regards to species
> and size. This was using monofilament with rods
> that few of us here would ever purchase. Celebrity
> fishermen are hostage to mass-market sponsor’s
> rods.
>
> I have a copy of a very rude email from a member
> of this forum to another that completely missed
> the paradigm of rod sensitivity. Fishing rods
> aren’t energized like tuning forks during a
> bite. The line that subtly pulls downward on the
> tip also neutralizes that type of vibration. This
> is basic Newtonian physics. The human reaction
> time to a touch sensation averages .15 seconds.
> Not only do rods in fishing situations usually not
> vibrate in ways where their natural frequency
> comes into play, but a faster transmission of
> vibrations from tip to hand is just a tiny
> fraction of this reaction time. The efficient
> transmission of force seems more relevant than
> frequency. Amplitude seems more relevant than
> natural frequency. Lightness, fiber density, and
> less buffer by low density things such as resins
> and guide adhesives seems most helpful. In the
> end, sensitive hands are more advantageous than a
> sensitive rod.


These are very astute observations. What fishermen interpret as a "vibrations" are really variations in resistance from something on the other end of the line. This is why with all else being equal, a longer rod will be more "sensitive" than a shorter rod. Whatever is resisting you - a lure, spinnebait blade, jig across rocks, a fish movement, etc., will be amplified to a greater degree as the 2nd order lever becomes longer.

Stiffness to weight ratio, frequency, etc., are more aligned with rod speed/recovery. This is what many refer to as simply "feel" which is not necessarily to be interpreted as sensitivity.

............



Edited 1 time(s). Last edit at 01/16/2023 09:11AM by Tom Kirkman.

Tom Kirkman Wrote:
------------------------------------------------------
>
> What fishermen
> interpret as a "vibrations" are really variations
> in resistance from something on the other end of
> the line.
>

Picking-up on the level of bites you described as “variations in resistance” is what I believe differentiates catch rates. It reasons that some level of tip bounce has to occur to get harmonic vibrations (unless you slap the gunwale of your boat). This requires enough energy to deflect the tip and there to be some slack in the line. While this does happen during fishing conditions, It’s my belief that these occurrences are either already missed fish or bites that would be detectable on a “Snoopy rod”. A small, sharp bite on braid might create harmonic vibrations, too. I’ll think more about that the next time I am fishing braid. Overall, though, I think it’s your subtle change in resistance that we need to be better able to detect.

Aleks, thank you for sharing the details on your research and development efforts. I really enjoyed reading about the new developments in antenna and fishing rod construction concerning sensitivity, and how one led to the other. I learned a lot.
I’ve always been confused about the term sensitivity. Back when I started building rods there were no such things as carbon fiber rods, small light guides, or braided line. All we had were fiberglass rods with god awful heavy guides and components, and we used monofilament line. However, we were still able to feel a fish bite. There were times when the bite felt quite strong, other times the bite felt subtle, and some times we felt nothing and just saw the line moving. We bragged about how sensitive our rods were back in those days, but had no idea what made a rod sensitive. Fast forward to today. We have high end carbon fiber rods, much lighter components and braided line. The rods today are much lighter, and feel much better in our hands. However, even with these modern fishing marvels, some bites feel quite strong, others quite subtle, and at times we didn’t know we had a bite until we saw the line move. Seems like some things have changed and other things have not. Like many others, I’m convinced there are multiple factors involved in sensitivity or its perception. Some are objective and can be measured and others are subjective and much harder to understand. Fishing tackle has evolved quite a bit in my life time.
Norm

This is not exactly on point, but...

I ate some barbecue and drank a couple of Bloody Marys just this Saturday with a guy who worked on a test program with the goal of imbedding sensors in and along the carbon fiber blades of wind turbines to gauge flex and stress (and I'm sure other factors) to anticipate needed maintenance and avoid unnecessary maintenance.

I don't have a technical background, but it seems some of the concepts could at least theoretically be applied to rod design. I assume the cost would be high, but... it's interesting to think about.

Good stuff Alex ...... really good stuff

Thank you for taking the time to post it.

Many thanks for the great post and information Aleks . While I agree that there is a subjective component to "sensitivity" , what I am confused about is why someone would dismiss any advance in technology that may improve an objective characteristic . My old hands will be just as insensitive as ever but perhaps the new technology will help offset the problem - however slightly . Thanks again for your post .
Ron

Aleks,
Thank you for such an intriguing, informative post, “A Sensitive Topic”. Coming from a composite background, it was very interesting to me to learn of the nickel-coated CF, especially the fact that the nickel does not actually bond itself to the CF but rather “shields” it from the matrix and consequently allows the core CF to transmit vibrations along its length without being dampened by the matrix. Without your understandable description, I would have lost money betting on the lower modules nickel “deadening” the transmission of vibrations along the CF filaments.
Being unfamiliar with “non-carbide formers”, and possibly comparing apples-to-oranges, I wonder if aluminized FG (AKA “Texalium”) transmits vibrations better than uncoated, equivalent FG?
Congratulations on a job well done; apparently, I’m not the only one who thinks so. I am here to learn.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

I try to consider expected fish behavior while focusing on detecting bites. Rainbow bites on shallow running lures are never subtle in our local lakes. These trout are big and aggressive nuisances when trying to catch bass. They are timing a 180 degree turn at the point of hitting a jerkbait as they don’t want to become osprey food. A walleye or largemouth repeatedly feeding near the bottom on small baits isn’t wanting to alert their forage to their presence by putting more vibration in the water than is absolutely necessary. It takes keeping contact with your bait on the fall and really being attentive. Most fish actively feeding on moving baits want to get them and turn back to re-occupy their nice ambush site. Panfish make small but quick pecks at their food while often rotating their bodies slightly downward. After I get mentally fatigued focusing on subtle bites with finesse plastics, I’ll switch to a moving bait to relax. I pull away from panfish pecks once I’m sure that’s what’s going on. I let a drift bobber give a visual clue of a steelhead subtly taking eggs in current. A big largemouth inhales a huge amount of water around a big plastic worm. When the line starts to move it seems best to pause very briefly and then send them the bad news at the moment the line movement is slightly interrupted.

My point is that there is a lot more to effectively catching fish than always having a rod that quickly transmits vibrations. How to decode those resistance changes is something I am still learning. Seeing people who are really good at it made me realize how much I was missing, There is an interesting synergy here between physics and fish behavior.



Edited 3 time(s). Last edit at 01/16/2023 07:28PM by Kendall Cikanek.

Ed,

Thank you very much for the kind words, I appreciate them greatly.

We list the type of fiber that we use in our blanks in the NFC Blank Catalog, and since not every fiber will undergo a successful vapor deposition process, I would rather not say which blanks in our lineup use this - as I don't want to "shorten" the R&D efforts of those that will try to copy.

Best Regards,
Aleks

Kendall,

Thank you for the background and input - our engineers would agree with you on the resistance aspect of sensitivity. In fact, if you look at the patent language, we are very specific to measure "low frequency" as a fishing rod is not a tuning fork. The issue with pure resistance is that it is very difficult to replicate on a consistent basis. While you can have a source that transmits vibrations at 60 hz, and 60hz in the US is 60hz in Japan/etc, dragging a lure across a surface with "bumps" cannot be replicated easily. (To hold everything constant, you would need to export / make available the same surface to anyone that would like to replicate the experiment) Using "low frequency" was the workaround, and although not "perfect" it was intended to emulate what a "fishing rod does"

Best Regards,
Aleks

Mark,

You are not comparing apples to oranges - aluminum / texalium has the exact same effect. The biggest difference being that the process to make Texalium is a chemical process that adds aluminum to fiberglass (most folks advertise it as carbon, or assume that it is carbon, but is in fact glass), the other issue is that aluminum needs to be added in a greater percentage to the fiber to achieve the same conductivity (you are adding more weight to get the same result) The data points are different for copper as well.

Best,
Aleks

Mark Talmo Wrote:
-------------------------------------------------------
> Aleks,
> Thank you for such an intriguing, informative
> post, “A Sensitive Topic”. Coming from a
> composite background, it was very interesting to
> me to learn of the nickel-coated CF, especially
> the fact that the nickel does not actually bond
> itself to the CF but rather “shields” it from
> the matrix and consequently allows the core CF to
> transmit vibrations along its length without being
> dampened by the matrix. Without your
> understandable description, I would have lost
> money betting on the lower modules nickel
> “deadening” the transmission of vibrations
> along the CF filaments.
> Being unfamiliar with “non-carbide formers”,
> and possibly comparing apples-to-oranges, I wonder
> if aluminized FG (AKA “Texalium”) transmits
> vibrations better than uncoated, equivalent FG?
> Congratulations on a job well done; apparently,
> I’m not the only one who thinks so. I am here to
> learn.