What is the best way to go about trying to identify a blank to replicate an existing rod?

Can of course static load the existing did but with guides already on it will react different than with a bare blank of course.

Other than building up multiple blanks for comparison, any tried and true techniques?



Edited 2 time(s). Last edit at 11/09/2021 06:34PM by Michael Ward.

Have you read the CCS Database info near tha top on the left? Lots of info on your subject there.

It might be helpful to ask what you mean by "action." Action is where the rod initially flexes. So when you mention "react" I wonder if you mean speed, or perhaps simply "feel."

To duplicate an existing rod on all fronts, there are a lot of factors in play - length, weight, action, speed, material, etc. The more of these you match the closer you'll be to exactly matching the existing rod.

This is where the careful custom rod builder has a leg up. By studying all these aspects of blank characteristics, you should be able to make at least an educated guess on which blanks are most likely to duplicate what you have now.

.........

Michael,
To compare the blanks, simply take the rod you wish to match and a test rod and simply hold the two rods side by side and press the tip against the floor or the ceiling and check for equal blank bending matching as you go from no force to maximum bending of the blank.

One can always use the ccc system to load each blank and compare the bend of each blank as specific loads are added to each blank.

This is a pretty straight forward way to determine differences or similarities.

Take care



Edited 2 time(s). Last edit at 11/10/2021 11:09AM by roger wilson.

CCS is easy to do and doesn't really require that big 4 x 8 sheet of pegboard. Inexpensive digital levels make AA a piece of cake compared to using the old angle chart. I check every blank I deal with, so comparing blanks is very easy.

Roger is mistaking speed for action. Action is where the rod initially flexes. Speed is relative reaction and recovery time.

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Is there a chart that lists where different rod blanks initially flex, and is there a chart which lists the reaction time and/or recovery time of assorted blanks? I suspect practical rod builders could put such information to good use - for themselves and their customers.

Michael,
If indeed you are looking for the same “action” as your title suggests, the easiest, most accurate and widely accepted method is to perform CCS to discover the AA. Although Roger’s “ceiling” method may be less sophisticated, it will afford a very good, quick visual reference; I have learned to like it very much.
But consider Tom’s statement to make sure you are not confusing “action” with / for “speed”.
Tom,
I am confused; In my book, Roger’s “ceiling” method is meant to discover the action of a blank / rod (where it initially flexes). Please explain your statement “Roger is mistaking speed for action. Action is where the rod initially flexes. Speed is relative reaction and recovery time.” 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.

Isn't it logical that someone could confuse action (which is described by speed terms fast/slow) with "recovery time," which sounds a lot like speed might be involved? An unfortunate consequence of conventions adopted a long time ago. Good point, Mark.

Phil Ewanicki Wrote:
-------------------------------------------------------
> Is there a chart that lists where different rod
> blanks initially flex, and is there a chart which
> lists the reaction time and/or recovery time of
> assorted blanks? I suspect practical rod builders
> could put such information to good use - for
> themselves and their customers.

Yes, there are dozens and dozens of charts that illustrate Action and how Fast, Moderate and Slow blanks initially bend. These come from rod and blank manufacturer catalogs going back over a half century now. In fact, I put one on the photo page less than about 3 weeks ago to illustrate such. [www.rodbuilding.org].

No manufacturer has ever produced a chart related to rod speed, other than to indicate that "rod speed" indicates how quickly a rod reacts and recovers. You can't use terms such as Fast, Moderate or Slow to describe rod Speed because these change over time as materials and designs change. A 1940's glass rod would have been Fast at that time, but would be Slow today. So you have no continuity in using those terms to describe rod Speed. Rod Speed is always relative from rod to rod and over time. What would have been considered "fast" in 1940 is "slow" today. This is why these terms do not suffice to describe rod Speed.

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Edited 1 time(s). Last edit at 11/10/2021 10:24PM by Tom Kirkman.

Would not "rod speed" be represented accurately and objectively by the natural frequency of the bare blank, with no weight attached to it when tested?

Yes it would. It would also do the same even with weight attached. Attaching weight does not change the relativity of the results as long as you do it to every rod measured. This is why the CCF works in determining relative speed from one rod or blank to another. It's not the number itself - it's the relation of one number to another that really matters.

But such numbers have not been offered by any manufacturer to my knowledge and would likely need to be explained to the buying public (or changed to a simple scale of some sort like most do with rod power). Action diagrams are easy, frequency explanations related to rod speed might not be. However, I do wish manufacturers offered something along these lines. It would certainly help rod builders fill in one more missing piece of a puzzle in terms of rod and blank characteristics. With some thought it could certainly be done.

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

I don't like the "feature" of CCS of having to add a weight which Dr . Hanneman, with good judgment I'm sure, specified based on the power of the rod. Because of this somewhat arbitrary weight add the forces involved in testing the rod go way up and the results don't reflect the true natural frequency of the rod/blank. He only did this because at the time there was no way to test for the true natural frequency without expensive equipment. But now we can do it with equipment we already have, add no weight to the blank/rod, and the forces are very low, not requiring much structure in anchoring down the blank/rod. A wrapping machine is sufficient.

I know of two different ways to accomplish testing for the true natural frequency of a blank/rod, and just about anyone can grasp the concept that "the higher the better."

Of course with some rod designs and fishing techniques the natural frequency doesn't really matter, so in those cases, it's a moot point. But for finesse fishing, being able to measure the natural frequency of the bare blank, and seeing how it changes with the adding of components, is valuable. And possible now without expensive equipment.

He wasn't trying to record the true natural frequency of the rod, just the relative speed from one rod to another. The instant you put something like "frequency" in a rod or blank catalog, you've lost the interest of 99% of the buyers.

When Fenwick introduced rod "power" numbers, they didn't explain how they got them, what they were based on, etc. Just simple whole numbers that were relative in nature. And that type system remains the most popular and most used system for fishing rods and blanks. Granted, they don't translate from one company to another, but fishermen get the idea without needing any explanation.

Manufacturers could, of course, take their own frequency measurements and assign simple whole numbers to them and achieve the same thing. But for whatever reason they don't seem to think it's worth the time to do it. Maybe somebody has done it at some point, but if so I'm unaware of it.

..........

It does not really matter what Dr. Hannerman was attempting to accomplish with CCF, the individual frequency of each blank or just the correlation of frequencies between blanks. One way or the other, his intellect provided all of us with CCS and CCF which had not been accomplished prior. We all owe a great deal of gratitude to Dr. Hannerman.
That graciously said, I believe he added the “stickTac” weight to the tip of the blanks simply to reduce the oscillations of the blank to a point which could be easily measured / counted by just about anyone living in that era without the sophisticated, readily available programs now available in our present era; his method served its purpose and did it very well. With modern advancements in technologies and consequently numerous readily available programs, the un-natural addition of “StickTac” may not be required any longer which should support a more precise evaluation of each blanks own, individual frequency. After he set the stage, I am confident Dr. Hannerman would be very pleased with the advancement of his original concept utilizing advanced technologies.
Our own Michael Danek has devoted a considerable amount of time and effort to pursue measuring a rod’s frequency in its natural state, without “StickTac”. I am impressed with his relentless pursuit of perfection and commend him for his efforts. While being very intellectual and analytical, he is also very humble. I hope to not embarrass or offend him by writing this, but he deserves admiration, acknowledgement and a simple “Thanks, Mick!”.

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

Thank you, Mark. I believe that if Dr. Hanneman could have recorded the true natural frequency of a rod, he would have. I believe I remember his stating that his adding weight was, as Mark mentions, to get the frequency into a range where it could be counted without expensive equipment like oscilloscopes. If he had had the technology that we have today I doubt if he would have bothered with adding weight to a blank.
It is clear that what Dr. Hanneman was attempting to do was to complete the description of rods in objective terms by measuring frequency.

"Although “feel” has always been
considered a subjective property,
it can be quantified on a relative
scale. Here for the first time is a
practical method for quantifying
rod feel and how to use it."
From: Dynamic Characterization of Fly Rods - Frequency and More

I am not proposing that rod makers put anything into a catalog, and I'm not interested in what 99% of fisherman think. This original post was asking about how to replicate an existing rod. As Dr. Hanneman argued, one facet of that is "feel," and he believed that "feel" was associated with frequency. I submit that the objective description of "feel" is best done by knowing the true natural frequency of a blank/rod. And we can determine that today without expensive equipment. To replicate an existing rod the best way, in my opinion, is to know its ERN, AA and its true natural frequency, then finding a rod with the same numbers.

And that's the problem - you cannot find a corresponding blank with the same frequency unless you buy it first. Unless the manufacturers list such a thing in their catalog blank descriptions.

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

"Tom Kirkman, “... I have tried to stress that for any such
thing to be useful, it must be converted or translated into
some type of simple relative scale. With a known length,
weight, power rating (ERN) and action (AA), we have
most of the pieces of the puzzle. However, we’re still up
against what I like to call efficiency or what others may
describe as feel. We have no relative scale to measure
that—you have to get hold of the blank or blanks in question and use your human sense of touch to gain this last
tidbit of information. It might be helpful if you didn’t have
to do that. ... It is in this area that a resonant frequency
scale would be most helpful. It could complete the final
piece of the puzzle, but again, it would have to be reduced
or translated in some way to a simple relative scale in
order to be widely understood and accepted. And of
course, you’d have to get the manufacturers to adopt it."

" . . . a resonant frequency scale. . ." = cycles per minute true natural frequency

Exactly what I've been saying for years.

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"And that's the problem - you cannot find a corresponding blank with the same frequency unless you buy it first."

A fairly high volume builder can have a "library" of ERN, AA, and true natural frequency data and will be able to quite well match the rod the customer brings in. I'm a hobby builder and I can do it in many cases even though my "arsenal" of rods is relatively limited. . Additionally, as one checks blanks there are unmistakable trends that appear which narrow the possibilities greatly. If the customer's rod has a relatively high true natural frequency then I know very well that most blanks will not match it. And I have to look at the premium blanks for a match.

One can argue that this scenario is not perfect, and I will agree with that argument, but I have not yet seen a better one which will allow one to accurately "replicate an existing rod."