Emory-
You may have not seen Bill Steven's post several days ago about supporting a finished rod at the center of the reel seat and weighing the tip. Same could be done prefinished using different sizes of guides temporarily attached to examine the differences in tip weight. As you mentioned -weight distribution is an important factor-guide weight differences will have a bearing on distribution.

Chris

Emery

If you change to being right everytime, we may loose our interest. Thanks, you may have just shown your "man-card".

Bobby

Emory;
What you are saying about measuring “the distribution of the weight” makes a good point.

While reading it I had an idea for a method to do so with out destroying the blank, but do not know if it is practical or would be accurate. This is what I was thinking and would like your input on it.

If you built a little stand placed at the center or front of the reel seat just high enough to allow the rod to pivot freely then took a slightly shorter stand with a V-fork top that the blank could rest in. Using exact distances marked down the blank or on a table top. Say tip then 6” then 12”, 18”, 24”, and so on. Then placed the forked stand on a flat gram scale like what Bill Stevens is using, and measured the weight of the blank at each predetermined location.

Would that effetely create a weight distribution scale that could be adopted in general and used to accurately make comparisons in “the distribution of the weight”?

New topic for future discussion... robbing from other post...

spacing micro guides

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Chris,
I did miss that but I do not think that approach will be a whole lot better, as far as determining efficiency is concerned, than weighing the whole rod. The problem is that the affect of added weight on rod performance increases approximately exponentially from the butt to the tip of the rod. The added weight that we as rod builders add toward the tip of the rod is what mainly drives the rods performance.
Weight distribution or what is called sectional weight is measured by essentially chopping the blank or rod up into very small pieces and weighing each one. There is software called Finite Element Analysis, that most mechanical engineers are very familiar with, that can do this knowing the materials and the dimentions. But the software is not very user friendly. I have screwed around with it a little and did not really get anywhere. It takes some training and also a fairly powerful computer.
I used to have a bunch of mechanical engineers working for me and are still close friends. If I were not so lazy I would get off my butt and have one of them put together a model for a graphite blank. I have got to believe that at least one of the blank manufacturers uses Finite Element Analysis but I do not know of any that do.



Edited 1 time(s). Last edit at 11/11/2008 12:49AM by Emory Harry.

Bass rods are build for many different applications. Rods for Shaky Head and Drop Shot present different challenges than those used for large swim baits. Critical thought on how these rods are used by fisherman and what are the desired features of each will reveal different sets of build priorities. There probably will not be a single fixed formula that will apply the same constants to all - each is different and even the words sensitivity/balance will be revisited on later Volumes of the M&M thread.

One thing that will not change is the fact that the lighter the rod that will perform the required tasks in the desired manner will prove to be a superior rod. The funny thing about this is the difficulty and importance of making a complete and accurate list for the "required tasks". A couple of them could be if it is too light it may not be durable enough or if it is too heavy it can not be used for extended periods of time.

Other parts of the ultimate puzzle for building a better custom rod will detail the relationship of the following:

Rod, Reel, Line, Lure, Fisherman



Edited 1 time(s). Last edit at 11/11/2008 07:48AM by Bill Stevens.

"Other parts of the ultimate puzzle for building a better custom rod will detail the relationship of the following: Rod, Reel, Line, Lure, Fisherman"

Bill imo you bring up a most critical point. However I would substitute the word puzzle with system - that is your "parts" plus target species, most fished habitat (e.g., open or structure filled water), most prevailing conditions (e.g., high likely hood of wind), ... all form a dynamic System. There is a principle of system's thinking that helps me think through the compromises (and I agree with Emory and others that there are always compromises) that have been raised when solving the "puzzle": If you optimize the parts of a system, you will sub-optimize the system. The converse is true as well: If you optimize the system you will sub-optimize one or more of the parts.

This is why I think your point about "complete" requirments is so important. This imo helps define how the System should perform (be optimized) and therefore allows the builder to decide intenionally which parts should be suboptimized, e.g., adding weight in components for durablity for hauling hawgs out of tree tops or eliminating every single grain possible for casting distance on SW flats.

I think this relates to Russ's thread up above about the value of books and other's comments about the value of this board. Threads like this Volume 1 helps me understand the "why to" just as much as the "how to" and this helps me understand the effect of suboptimizing a part - i.e., thoughtful compromises.

Thanks for Volume 1. I will not always use micros but I now know more about when I should consider them, and when I shouldn't.

PS: There is also a design principle that I think applies to this thread: Great design is not when there is nothing left to add, it's when there is nothing left to take away" (Antoine De Saint-Exupéry, pioneering aviator and suthor)

I use FEA software, and information gained from the analysis everyday in designing parts and assemblies (turbochargers) for my day job, it is an amazing tool that can give you tremendous insights into your design. I have toyed with doing analysis on rods, but as I am sure you all know the apparently simple structure of a fishing rod blank is extraordinarily complex. It is not a homogenous material, you have various fibers of different modulus at different orientations, different scrims, different flag patterns, different resins, different resin to fiber ratios, different finish sanding amounts, and of course compound tapers of the mandrels. None of these variables are knowable to anyone but the blank designer. I know that specialized carbon composite analysis software is available, it is used by the aerospace and race car industries to name a few, I would like to believe that some of the better manufacturers have tools like this, but they are extremely expensive.

Things like center of mass or polar moment don’t even require FEA software, any modern solid modeling CAD system will give you information like that once you have an accurate model constructed. With FEA you can get much more like modal frequencies or deflection curves for a given load, sort of a virtual CCS. All of this would be very valuable information, but the complexity of accurately modeling the blank itself is quite a hurdle to get good results. The only way the end user could get close would be to take many load deflection measurements of the blank, then build your CAD model and iterate until the results matched the measurements.

Mike,
I could not agree with you more about how extraordinarily complex a carbon fiber fishing rod can be. The more you think about it the more complex they get. However, I think that most of the variables that you mention are available with a little work plus some of them only have second order affects. Even if some of the variables had to be estimated that would still be better than nothing.
I do not share your belief that the blank manufacturers are using FEA. And I think that there are a number of things about blank/rods that are just not known. There are a lot of guesses but in some cases I think that is all they are is guesses but could be determined with FEA.
What is your estimate of the time it would take to do the model assuming someone else came up with the variables?
If you are interested in possibly pursuing this send me an e-mail. My e-mail address is [[email protected]]

I wonder how many fishermen are reading all this science stuff and saying - geez, it's only a fishing rod.

If they only knew what the warped minds of builders contrive in an effort to make their fishing success better.

Billy;
I am quite sure you can now sympathize with Science Fiction buffs who are required to scan read the Liberl Arts magazines while sitting in the lobby of the dentists office waiting to have holes drilled in their teeth. One question for you - how many pounds of lead do you hang on your "drop shot jig rod" on a typical party boat in 500 feet of water. Have you ever thought about weighing your tip weight on a typical 10 inch Spyder closed fancy wrap on that rod.



Edited 1 time(s). Last edit at 11/11/2008 07:32PM by Steve Gardner.

Well the ones saying "Geez it's only a fishing rod" will never build a very good rod nor perhaps even recognize a good one from a not so good one. I suspect they can get all they'll ever be able to put to good use at Wal Mart.

I'd be the first to agree that you can go overboard and get involved in all sorts of stuff that doesn't amount to a hill of beans once beyond a certain point, or in practical use out on the water. But I'd also say that the more a builder considers these things and even worries over them to a practical amount, the better the rod he's going to build.

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

Mike,

You probably know this but for others, once the prepeg has been heated and cured, you arrive at a situation where you really no longer have all those separate pieces in play - you simply have a tube; a single unit for the most part. Granted, it's not completely simple - the diameter and wall thickness vary and you may even have different materials at different locations of the blank, but much of the original varied pieces are now part of a single unit and behave as one. You may find different characteristics at different points in the blank, but most of what you'd want to know (I think what you'd want to know) would be found by examining the blank as a unit although at different points.

I have worked with several blank designers and the current process is not nearly as technical as you might think, although it is more precise than it used to be. But the current technology in blank making is getting ready to be tossed out the window. In the future, blanks will be poltruded and/or molded. The process will be easier to control and quality control will be higher. The entire process will be revolutionized in the next 5 to 10 years.

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

No telling what will fly through the air and land on these boards when the blank structure is truly amorphus throughout! I can see it now order a tube of thermo plastic nano material and squeeze out the blank of your dreams.



Edited 2 time(s). Last edit at 11/11/2008 10:00PM by Bill Stevens.