Mr. Emory,

This fomular apply to fix weight of the golf club head, no ? Do you think it apply to a bare rod blank ? Just thinking.

Thank you very much for the info. I will read more and perhap ask more questions if you don't mind.

Ben

Ben,
You make a good point. John Kaufman was interested in golf clubs resonant frequency so his formula tends to be optimized for that. However, it will still work for rod blanks and is the best formula for blank resonant frequency that I have seen. If you are familiar with calculus, I think that what is really needed is a calculus term dM/dL which is change in mass by change in length. Basically a term for mass density.

The task of the clubmaker is completely different from the maker of a fishing rod. Power, club head speed and impact torque at contact drive the design parameters of the golf club designer. I would suspect that Gary Loomis would be an ideal person to dictate a message that would describe the differences in the the primary tasks faced by rodbuiders and clubmakers. The rodbuilder is not required to deal with COR (Coeficient of Restitution) as it relates to torque values. Gary knows there are others reading this thread that reside in both the rodbuilding and golf worlds! This could create another round of espionage that will rattle a lot of cages. One potential question could be - will the advanced material of the future be spineless!

Emory in todays world of rod blanks - Generalizations

All blanks are not perfectly straight

Amplitude, direction of motion and frequency of properly restrained rod blank tips are changed by altering orientation.

If you select a blank by frequency on any axis and build on another is the "feel" diminished.

Is this information to be used for building a better blank?

Will the information assist a custom builder in the selection of the proper blank?

Will the information be valuable to a fisherman seeking a rod?

If a blank manufacturer uses the process to produce a superior product why would the informaion be shared with others who compete?

Will the information ultimately result in marketing information. Will this information be possible with eighth grade comprehension levels?

How do you envision this data to be utilized and by whom?

The (Italian made) Gatti blanks I have handled display noticibly less spine than most, if not all other blanks I have handled. What does Gatti do or use which accounts for this apparently reduced spine?

Thank you Emory.
Finally a precise tool for the quantifiable measurement of the dynamic response of rod blanks.
When coupled with static rate deflection for range the blank can be effectively profiled and matched to any other blank for desirable characteristics.
The analysis can be used to determine differences between blanks and used as a tool for determining variability's in manufacturing materials and processes.
Since the rod is a composite structure the data will see the combined effects of all materials and their relative densities and percentages.
Differences in mandrels, taper variation, resin density, fiber material analysis, fiber weave and fiber density may all be viewed as variables and charted relative to differences and potential trends.
Whether this info is to be made available to the custom builder will determine how much we still have to learn.
The effects of the rod build can then be scrutinized to determine how far the build has modified these characteristics and can the effects be predicted and minimized.
Selection of grip, reel seat, guide number and guide inertia will all carry a quantifiable price tag to the measured efficiency of the blank.
The net result could be the advancement of rod building to another level.
The down side is it will also apply the same measurement values to our errors.
The upside is now we are aware of the value of those errors we can assign priorities to the successful elimination of them.
We may all need to become technicians to properly evaluate what we've built and to learn how to make further improvements.
Would it be possible for Emory to publish an equipment list and procedures for the appropriate results ?

I've got a lot more to learn and only one lifetime to do it in.

Eugene Moore

Eugene,
I worked for Tektronix for many years on this type of equipment and that is the reason that I have it and use it often. I do not think that you want to try to duplicate it though. However, these days this type of equipment is very inexpensive on the internet. But the equipment that I use is really overkill for measuring blank or rod resonant frequency. The type of inexpensive device that is shown on Jon's NFC blog is much less expensive and much easier to use. It operates on the same principle as the Cub Scout devices on the CSFA.com web site. They are just electronic counters with a photo detector input and they just use the backgound lighting as the light source that is interrupted, and counted, as the blank oscillates back and forth in front of the photo detector. I think that if you looked around on the internet you might be able to find one of these that was very cheap.


Bill,
I was an ardent golfer for many years and I think that I have a pretty good though admittedly just basic understanding of what golf club manufacturers are attempting to achieve with their carbon fiber shafts. I think that if you would read over the technical notes on the CSFA.com site you will have a better understanding as well. Beyond that I do not really understand what your point is or what you are attempting to get at so I think that I will not attempt to address your posting.



Edited 1 time(s). Last edit at 04/03/2010 01:54PM by Emory Harry.

I got these terms definition (below) from a golf website. Hope it will help when we reads the tech notes. I am not affiliated with CSFA or anyone else on these board.

Flex - Generally, flex is defined as the relative stiffness or overall bending property of a shaft.
Manufacturers typically categorize shafts by regular, ladies, senior, firm, stiff and extra stiff flex.

Frequency - A more thorough, accurate, and precise way to measure the flex of a shaft is by frequency.
The frequency scale used by Hot Stix Golf is based on the length of the club as well as cycles per
minute (CPM). CPM is measured by clamping the club at the butt end into the frequency monitor and
measuring how many times the club passes a certain point over a given time. A frequency number of 8.0 is
extremely stiff. 1.0 frequency is very soft.

Torque - The amount of resistance to twisting that a shaft has is called torque. Each shaft has a
different torque, and it important to match the correct torque for your individual swing. The lower the
torque number the less the shaft will twist when force is applied. This also will make the shaft feel
"stiff".

Swing Weight - Commonly, swing weight is known as the "feel" weight of the club. To determine the feel,
simply hold the club up waist high and take notice how heavy the head feels. Some golf clubs will have a
heavier swing weight than others by design. Variables in swing weight can result from length of the
club, graphite vs. steel shaft, head weight, and grip weight.

Kick Point - The position on the shaft that exhibits the greatest amount of bending when the shaft is
compressed at one or both ends. This reading is important because it helps determine ball trajectory.
The lower the bend point the higher the ball flight. Likewise, the higher the bend point the lower the
ball flight.

Center of Gravity - The club head balance point that is controlled by the size of the club head and the
location of the head weight. The lower the center of gravity - and the farther back it is from the
clubface - the easier it is to get the ball airborne.


Later.

I shouldn't even be in this "techno" conversation, but from a fishing standpoint only.......If it can be something used by manufacture's to build a better blank, help the rod builder make a better rod, or in the most IMPORTANT END: give the fisherman a product he can tell is significantly better than what he's currently using, then so be it please. If it doesn't fit this realm, it's less than interesting and falls more into marketing areas.

DR

Emory I read the material over three years ago when this subject arose on this forum. We had telephone and email contact at that time.

I am not attempting to make a point.

I made a statement that golf clubs and fishing rods present different design parameters.

I am asking how the resonate frequency measurement will be used in the fishing rod industry.

Will it be a quality control issue for blank makers or a marketing tool used to drive markets..

Bill:

Well stated.

Bill,

Not quite sure, but this is what i think. It's about NFC blanks coming close or exact to G-Loomis Blanks. and quality controls is done using Resonance Frequency. Other topic is on my interest. That's all.

Ben

Bill,
Because all of the characteristics of the blank or rod show up in the resonant frequency manufacturers can, for example, use it to measure the characteristics of blanks over time as a quality control tool, to insure that their processes or their materials are not changing over time. They can also use it as a quantitative measure of a blanks improved performance when they change the material in a blank or change a characteristic of a blank. There are many things that a blank or rod manufacturer can use it for particularly after they have spent some time with it and developed experience with it.

As far as custom rod builders are concerned, I think that there are probably even more applications for it because custom rod builders tend to do a lot of tweeking of his or her rods and making a lot of changes. But the changes at present are mostly just based upon guesses of what the outcome of the changes will be or what he or she has read or been told they will be. In fact, in my judgment, most of what custom rod builders are doing is not based upon something that can be quantitatively verified. The use of resonant frequency would make possible this sort of verification of the custom rod builders efforts.
A good example of my point is, you are a big advocate of micro guides. But can you tell me, not with some of your subjective beliefs but with quantitative facts, measured performance parameters, where the improvements in rod performance are? I submit that you can not but you could if you were measuring rods resonant frequency.
The problem for the custom rod builder is that no inexpensive, easy to use device for measuring resonant frequency is readily available for the custom rod builder. My early conversations with John Kaufman was an effort to get him to modify one of his products, mainly to make it as inexpensive as possible, so that it could be sold to custom rod builders but he was very busy and John is an excellent golfer but not really interested in fishing. I also thought of designing one myself because from a design standpoint it is a very simple device but I did not want to put the energy that would be required into manufacturing and marketing such a product.
The problem for the custom rod builder is not what would he or she do with resonant frequency if he or she could measure it. The problem is that no practical device is available for the custom rod builder. And also unfortunately, though I am a big believer in the Common Sense measurements of Power and Action, I do not believe Common Sense Frequency works in the sense that it cannot be used to make the sort of measurements that custom rod builders need to make. It was developed to give a rod builder a sense of the rods feel. It does not really measure the blanks or rods actual resonant frequency and was not intended for that use.



Edited 1 time(s). Last edit at 04/03/2010 07:04PM by Emory Harry.

For the average builder, it is not the resonant frequency itself that will be useful - it will be the relationship between the resonant frequency of one blank or rod to another blank or rod that matters. No one will ever be able to look at a resonant frequency measurement and implicitly state something like, "This reading indicates a fast action blank, made from IM7, sporting micro-guides and with no exterior finish on the rod blank." The fact that so many variables influence resonant frequency means that it is impossible to draw such specific conclusions from an RF number, at least where blanks and rods are concerned. So such measurements are most worthwhile to rod builders when used as a relative means of comparing one blank or rod's "Speed" to that of another.

That's the major benefit of the CCF (Common Cents Frequency) - it allows the builder to compare one blank or rod's relative frequency to another by a simple means that doesn't require any specialized equipment. The numbers provided by any relative system of measurement mean very little in and of themselves - it is their relationship to other other numbers (higher or lower) that are most important, at least where the average rod builder is concerned. And the CCF will certainly do that and do it very easily.

Few builders will ever invest in the equipment necessary to obtain actual resonant frequency measurements, although major blank and rod manufacturers might. If they did, or do, then you would have a very good overall indication of a rod's "Speed" which I believe would be very helpful and descriptive if added to the standard catalog specs. But the same thing can be achieved with the CCF, if a relative comparison is what you're after.

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

Tom,
I agree with most of your points but not all. RF is certainly most useful for comparing one blank or rod to another as you point out but then what you can infer from the difference is what is really important. And once you have experience using RF then the rod that is being compared against can be a mental one. Actually, I think that if you think about it all measurements are comparisons. The comparison may be against an inch or a pound or it can be against an ideal rod blank.
As far a Common Sense Frequency is concerned I do not think that I agree with you. A number of years ago, long before Bill Hanneman introduced Common Sense Frequency, I made literally hundreds of measurements for a Doctor McGuire at HP labs. He wanted to measure the resonance of blanks with several increasing weights. Weights that would allow the frequency to slow down enough to be counted by eye. He had put together software that performed a regressive analysis. It calculated from the different frequencies at different weights what the frequency would at zero weight. It turns out after a lot of work on both of our parts over a period of months we concluded that it would not work mainly because the relationship between weight and frequency was so non-linear. If you look closely at Kaufman's formula for resonant frequency I think that it becomes apparent why. This is the problem with Common Sense Frequency. When you add weight the resulting frequency is almost meaningless. All it tells you is that the frequency is higher or lower. It is not a quantitative measurement. Jon's technique of dropping the blank on a concrete floor works as well or better for the raw blank.
As you know, Bill Hanneman developed Common Sense Frequency, and he called me and we talked about it several times on the phone before he published it, mainly to give fly rod builders and fly fishermen a sense for a rods feel. He was not concerned with any other use of frequency at the time. I guess he achieved what he was trying to acheive but in my judgment what he achieved is not a measurement of frequency that can be used for any quantitative purposes.



Edited 1 time(s). Last edit at 04/03/2010 09:46PM by Emory Harry.

Hey Guys,
Now you'r starting to gore MY ox.

I have been asking (on other sites) for several years the following question, "What can an angler do with the knowledge of the resonant frequency of a fly rod blank other than to compare it with the value from another blank?" I have yet to recieve an answer.


Certainly, it can be useful for a blank manufacturer to use as a tool for quality control, as he knows the variables he can control to maintain consistency. But he does't really need the resonant frequency value, any precise method for measuring frequency will suffice.

In itself, for the angler, the resonant frequecy value is little more than an interesting number. It has no predictive capabilities whatsoever. For that one needs to know something the K and m values of the rod and the harmonic oscillator formula. Believe me, you don't want to go there. (Been there, done that.) It's not worth it.

To put things in perspective, consider the resonant frequency of a rod blank to be 195 cpm. By the time the builder attaches the necessary hardware (e.g., guides, etc,), the frequency of the rod itself is about 130 cpm. (This is a factor controlled to some extent by the builder.)

Now, before one can use it to fish, one must attach a line and a lure. (Just consider it weight.)

If the blank is to be used as a spinning rod, the amount of weight needed to to be added (i,e,, recommended lure weight) is that which will reduce the frequency of the "outfit" to about 105 cpm. Any more or less is a function of how the angler wants his "outfit" to "feel". That is, to adjust the frequency of his "outfit" to match his own PPF or Personal Preferred Frequency.

If the blank is to be used as a fly rod, the weight of line (ignore fly weight) required is that which will reduce the frequency of the outfit to about 83 cpm. Any more, and the rod will begin to feel like a bamboo rod (CCF=65 cpm.).

Bill,
I think that you and I must have been typing at the same time. And I think that you and I are very much in disagreement.
First of all, to be accurate it is not really the weight that affects the resonant frequency and it is also not the mass either it is the inertia that is a result of the mass and is also a function of the velocity of the mass. Actually if you look at Kaufman's formula it is even more complicated than that it is also the distribution of the mass. And even kaufman's formula is an expression in algebra that can only be accurately calculated using calculus. He uses total weight and weight at the tip of the shaft. This is his shrtcut for mass density or mass distribution but mass is obviously distributed all along the length of the shaft or rod blank.

I agree with your second paragraph that "all that is needed is a precise method of measuring resonant frequency". But Common Sense Frequency is not a PRECISE method of measuring resonant frequency because of the major non-linearities that result when weight is added to the blank or rod particularly when it is added to the tip of the blank or rod.

As far as you third paragraph is concerned, I do not think that you could be more wrong about resonant frequency being only an interesting number but not really useful. Maybe that opinion comes from your use of the text book formula for resonant frequency that you refer to (one over two pie times the square root of the spring constant over the mass). If you look into it you will find that this formula is a simple formula for a beam or a pipe and does not even come close to covering the variables in a structure that that has taper and varying wall thickness.

In your paragraph four, with all due respect, I think that you are wrong. With careful use of resonant frequency a great deal can be predicted. Plus isn't it a little bit illogical for you to argue for CCF and make the statement that all that is needed is a precise method of measuring frequency and then make the statement that resonant frequency is useless???

In your paragraphs 5, 7 and 8, again with all do respect, I do not think that you put things in perpective at all. In fact, I think you do the opposite and show your bisa toward fly rods and fly rod "feel".



Edited 1 time(s). Last edit at 04/03/2010 10:40PM by Emory Harry.

Emory,

What Dr Bill achieved is what he set out to achieve - a means for a relative comparison of one rod's frequency to that of another rod's freguency which relates to the relative speed of reaction and recovery between different rods or blanks.

There is no way you can take the relative frequency number for any particular rod or blank and tell me what it's action, power, weight distritbution, component use, etc., etc., etc. is. This remains a game of relativity and for that purpose most builders will find it far less expensive and much easier to use the CCF than anything else out there.

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

Tom,
You are right I cannot take a blank or rod that I know nothing about and tell you from the resonant frequency what the action or power or or length or the material it is constructed from is. But I do not think that is what the custom rod builder normally wants to know. What he want to know is something like, how much does this set of guides improve the performance of this blank or how much does this decorative wrap reduce the performance of this blank. He or she can get a very good indication of this from the change in resonant frequency. And if, in the case of the guide changes, he or she trys several sets or guide configurations he or she becomes experienced enough with the affect on resonant frequency of different guide configurations that he or she can tell with the next blank that he builds into a rod generally what the affect of different guide configurations will be.
Believe it or not, I can measure the resonant frequency of a blank, look at its characteristics, action, power, length etc, and do a pretty good job of estimating what the affect of a different guide configuration, or most any other change, will have on the rod performance of that blank. I believe most other custom rod builders could do the same if they became familiar with the measurement of resonant frequency. However, I do not believe that this is possibe with CCF because of major non-linear relationship between frequency and added weight to the tip.

I hope this Internet Fourm thread gets placed in the "Rodbuilders Time Capsule" for future opening.

There are very few people who have specific knowledge of the importance of the terms "resonate frequency" and "frequency" as they apply to design, use and marketing of golf clubs. Emory please check the date of Mr. Kaufman's work and validate the current status.

Here is my prediction:

The terms "frequency" and "resonate frequency" will have the exact same impact on the fishing rod industry of the future as they have on the golf industry on this date.

Bill,
I do not understand what you are attempting to get at. And, please, it is not a question of marketing @#$%&, it is a question of physics. Resonant frequency has been a useful tool to electrical and mechanical engineers and physicist for a couple of hundred years.