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Calibrating a fly rod.

Started by troutphisher, October 16, 2007, 19:45:59 PM

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troutphisher

I have often wondered about the natural frequency of bamboo rods, and noticed when I hit that frequency during casting practice in the lawn. I have experimented with different methods to find the natural frequency of the rods I own. I Finlay found a study, that has some interesting data, and test methods for calibrating a fly rod to a line weight.

This is a very interesting study, in that it measures flex both free form and flex as a mass acceleration component.

http://home.att.net/~slowsnap/calib5.htm
The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Peddler

The little I scanned of those reports was rather interesting. I couldn't help but notice the SagÄ— results are what I've suspected for a while. I wish they had the 5 weight TCR in there. It feels two line sizes (or more) heavy until you get a boat-load of line out past the rod tip.

As far as I'm concerned, this kind of cold, scientific data is about as far away from the essence of fly fishing as one can get.
The early bird may get the worm,
but the second mouse gets the cheese.

troutphisher

Lets see, you agree with the findings you scanned, but think the science behind it cold.

I see it as scientist wanting the knowledge to know how a fly rod performs, and what makes a perfect cast when all forces are balanced.

As a certified caster, you must have had the same feeling, when you hit the "sweet" spot and knew the rod was performing at it's optimum flex to load ratio.

It is that you just don't understand the science, or you don't like science in general?

Merciful Friggan Jeeeeezzzzzus!!!!!
The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Peddler

Actually, I replied to see if you are still an on-line asshat. You are.
The early bird may get the worm,
but the second mouse gets the cheese.

BRFFF

well i guess i'll be putting a 7 wt on my sage sp

Txfly

#5
...So if I can cast the tip of your four piece further than you can throw the whole rod, do I still get my case of beer?

troutphisher

Quote from: Peddler on October 16, 2007, 21:07:05 PM
Actually, I replied to see if you are still an on-line asshat. You are.


Hence the 1700+ smites....LOL
The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Silver Creek

I ran across that article several years ago. It is very similar to the common cents method of rating rods.

I happen to agree with the basis of thier theory which is:

(A) The performance and feel of fly rods is based on the the physical properties of the fly rods.

(B) Those physical properties can be quantitated.

The person who disagrees with either of those two propositions must then lay out a reasoned response as to which proposition is incorrect and why. For example, one could agree with proposition "A" but not "B'. Then one needs to state a theory and a factual basis why one cannot measure the properties and/or why those measurements are inaccurate.

I happen to accept both propositions as true and the measurements as valid. However I also believe that there is more to feel than stiffness and natural frequency. So my view is that those measurements are fine as far as they go. They provide a place to begin just a I believe the Commen Cents method is a beginning.

Fly casting is a physical act and fly rods are, when all the trappings and mystique of fly fishing are removed, just tools. As as been said before, a fly rod is a flexible lever. It can be a very expensive lever but it is just a lever. The mystique occurs when a fly fisher uses the tool in plying his craft.

Are we any less impressed with the Mona Lisa when we consider that it was painted with common oil paints and brushes? The obvious answer is no. Let us not confuse the art of fishing with the tools of fishing.
Regards,

Silver

http://tinyurl.com/kkctayx


"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy

jscagline

Quote from: Silver Creek on October 17, 2007, 10:03:33 AM
....Are we any less impressed with the Mona Lisa when we consider that it was painted with common oil paints and brushes? The obvious answer is no. Let us not confuse the art of fishing with the tools of fishing.

I like that.  Food for thought.....
The truth hurts but not as much as a gas guzzling, eco wrecking SUV hitting you at 100 MPH!  Yeah baby, yeah!

troutphisher

The reason I like the study was it gave quantitative data, and that data could be used to predict the action of the rod. With so many different rod manufactures, and the different basic structure of bamboo fibers in the cross section, it seemed reasonable.

But still there is the human element, we are the initial exciting force, that makes this instrument of fishing perform so well. With out human intervention, the rod is just a stick in equilibrium, motionless. 

So will this study make a person a better caster?
Probably not, but it is interesting physics behind the scene.

The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Silver Creek

What I think it will do is help us understand and choose a fly rod that matches the type of rod we prefer. But only if we choose to use it.

I believe that knowing how something that we use works is better than not knowing how something works. Knowledge is always beneficial but only to those to use it. Will it affect the enjoyment we get from fishing? Yes, if we can use it to choose a rod better suited to what we want to do. Will it decrease the enjoyment of fly fishing for those who don't use it? Not really, because they will never know what they are missing.

So just as there are many fly fishing books that are very helpful but never read, just as there are many flyfishing instructional videos that are never viewed, this knowlege is there only for those that take the time to understand and apply the knowledge.

I happen to enjoy this stuff. Others definitely could care less. But that doesn't mean that because it has no value for them, it has no value for you or me.

That leads me to another opinion on the science of fly rods. If any system of rating fly rods is going to reach and influence more than a minority of fly fishers, it need to be a system than can be understood and applied by the majority of fly fishers. I think that is why the line rating system of fly rods has been so successful. It is simple and to the point. But the rating manufacturers give to their rods is not always accurate.

What these researchers are trying to do is to move to the next step - a step that involves actually taking laboratory measurements of the fly rods and trying to correlate them with fly rod performance. Because the work is preliminary and is not in an easy to understand form for the majority of fly fishers does not mean it is not valid. What it means is that more work needs to be done to distill what is still too complicated into a form that is understandable and and acceptable by the industry and consumers.
Regards,

Silver

http://tinyurl.com/kkctayx


"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy

troutphisher

This is some what of a Paradox, sizing rods. Take into account the different materials and variations within the subsets. Bamboo is a classic example of this. The Bamboo plant has some significant variations in the structure of the fibers. No two plants are exactly the same.

Rods made from separate culms have slightly different characteristics. Then you have the variation in drying times and temperature. On top of this you have the rod makers adding variation through different tapers.

To come up with a standard taper for a given line weight, would be quite a chore, and may not satisfy all the anglers out there, especially in bamboo.

But it would be nice if there were some standard tapers matched to a line weight to start with. Then you could experiment and have a benchmark to gage from.

Graphite is a more controlled man made element, with tight controls or limits on process variation. This allows them to make "cookie cutter" parts with very little variation between parts.

It seems to me the best one can hope for, is to find a taper you are comfortable with, and match a line to that taper, where you line up for more flex, and slower action, Or line down to get faster action with less flex.

I may go broke trying to solve this  ;D
The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Silver Creek

Lets not forget that when we fish, we do not cast a given length of line but with a range of line lenghts that vary as cast and as we fish. Even under the AFTMA system of rating lines and weights, the actual weight of various 5 wt lines, for example, are not identical from brand to brand, nor is the distribution of mass along the the initial 30 ft of 5 wt lines.

The requirements of any practical system or rating fly rods is then not to categorize a rod with a high degree of precision but to give more useful information than the current rod/line rating system. We just need a system that is close enough to be practical and yet simple enough to be understood such that an engineering degree is not needed to understand it.

For example, when synthetic fly lines were developed we had level lines and tapered lines. Then we had WF lines. Originally we had just plain sinking lines. Now we have Type 1, Type 2, Type 3, and Type 4 sinking lines in various specialty tapers. We have cold water and tropical formulations of coating. We have a myriad of specialty tapers for bass and pike and large flies. We have tapers for spring creeks and delicate presentations. As fly line manufacturers developed new line technology, they agreed on how fast a line had to sink to be rated type 1 to type 4. This has helped fly fishers understand the various fly lines and compare apples to apples.

Meanwhile fly rod designations have remained unchanged with basically a line wt designation and some sort of generic description of the rod action - something like a 5 wt rod with a med-fast action. We have no more information about the performance of fly rods than we had 30 years ago. I submit that understanding the myriad of fly lines is much more precise now than if it had remained level vs tapered and floating vs sinking as it was years ago.
Regards,

Silver

http://tinyurl.com/kkctayx


"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy