I have been watching this thread for sometime and have come to the conclusion that it is "much ado about nothing important to fishing!" I'm of the persuasion that 99% of rod failures are due to abuse or accidents.

Robert,
As to the blank failure you've described, I believe the guide placement was quite good and the failure would take place at a lower value if this position had been centered between two guides. This is how I've read the math. Please correct me if I'm wrong. The only better choice would have been to place the guide directly on the break location. Sounds like the blank was incorrectly rated for the line used. The blank manufacturer missed the mark.

Phil-I agree with the your 99% assessment. But I think it l makes for interesting reading. I don't pretend to understand all the technical stuff. I like Billy V's injection of practical sense-gives my brain a chance to rest between the other stuff. I think nearly all blank and production rod builders attempt to balance performance and durability. Interesting also to watch the occasional production builders push the envelope and market rods with a greater emphasis on high modulus and low weight (or just low weight) at the expense of durability and then watch them sweat and backpeddle when warranty issues threaten their future business lives.
That 's not something I see as often in production builders who make their own blanks....St. Croix. Loomis, Rogue, Lami, etc., but more often in the new guys on the block grasping for a market share they have not earned but have attained on hype and slick marketing

Chris, you bering up a good point regarding warantees on pushing the envelope with high modulus blanks. I was fearful abotu teh warantees when I built all my rods on GUSA blanks, but the way I fixed that was to actually fish teh rods for a coupel of seasons and figure out the limitations of the blanks myself, and pass tha tinfo onto my customers. I never allowed a defective blank to walk out of my shop, everyone who got a rod from me got a stern explanation that if the rod broke it woudl be on them, and their fault. I also taught them how to properly use the rods, and fortuantely the only peopl ewho have broken rods have broken them due to their own screw ups, and don't ask me for freebie replacements. A lot of the warantee issues can be handled up front, but for a guy doing high volume sales of rods, especially through cosignment where they do not have the opportunity to make the warantee issue clear as day - it has to be a nightmare to deal with.

REgarding a blank Manu releasing a blank which had breakage issues - it happens. I know the GUSA SW65H was notorius for breaking, as well as the Dragon - both were redesigned and the problem taken care of. Obviously, teh fault is with the Manu for releasing the blank, but I also lay blame with teh builder for just building on a blank they are not familiar with.

Mark
My commiserations.................opportunities lost are often gone forever.........if there is a next time you know to keep your ears pinned ...........hey.
The thing is you never know what the pearls of wisdom are when you first hear them.............the regrets come later...............usually much later when you twig to the potential significance of those few words...................Don't feel too bad..............I've heard and read stuff I thought was psycobabble until a penny or two dropped much later.
In the next few weeks we will run up some numbers and see just what significance they have in the technical side of things one issue at a time.............. if no flaw is found in the physics & formulae I originally posted.

Robert
We will use the experience you encountered to see what difference a range of guide locations might have made.

Mike B
He He.................you are not playing fair...............I post up 2 lousy short formulae and bring the wrath of @#$%& on my shoulders..................Owen posts up 10 pages of reference formulae and you are happy................. He He.......................not fair..............

sorry, double post



Edited 1 time(s). Last edit at 07/12/2009 06:11AM by Owen Dare.

Mark,
Go to the blackboard and write 100 times
"I will pay more attention on class excursions"

What you describe does sound like some sort of Finite Element Analysis system, but it would be unusual (though not impossible by any means) for a manufacturer to write such software themselves.

For the naysayers that feel that any complex theoretical analysis of the loads in a blank have no benefit, let me throw out a scenario for consideration.

It would seem to me that the limiting factor in trialling new designs is the steel mandrel upon which it is built.
These are very expensive to make and by virtue of the fact that they have to be withdrawn from the blank from one end, the shape must be essentially a cone.

A similar limitation used to exist in anything that required dies to manufacture, such as in injection moulding.

Then along came something called stereo lithography.
In rudimentary terms, a 3D model is created using software.
Then lasers are fired into a special gel which cause it to harden in the exact shape of the original design.
This gel model is then used to make a casting at much lower cost than having to make a new die for every design modification.

It is even used in medicine.
I saw a human skull being modelled once. they took a ct scan and fed it into the machine so the surgeon could practice on a 100% accurate model before the main event.

Now what if....
A blank manufacturer came up with a new material or design concept using FEA that required a complex compound shape other than a tapered cone?
You can't make it on a mandrel.
But using Stereo lithography and some investment casting techniques we could see some really revolutionary designs and materials.
Until now we have only seen Evolution, not revolution.

Would the advantages be worth the cost?
That's the 60K question.
Is there a better form than what we use now? probably
For the reaasons I stated earlier, I doubt we'll accept anything too radical, but why should we not explore all the possibilities?

Such methods have already been employed to make rod banks and if not for cutbacks in a certain company's R&D work due to new ownership it might already be on the market. In the future rod blanks will be molded or pultruded. And it won't be one of the blank companies you're familiar with that brings this newer blank manufacturing method to the market.

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

Mark,
What you probably saw was the computer running their IPC algorithym.
This was derived in-house from from a series of equations for curve fitting developed 40 - 50 years ago.
The equations enabled an exact curve to be developed to minimize acceleration factors.
They are quite proud of this acheivement and rightfully so.
In the hands of a skilled rod designer he can tailor a rod for any condition requested.
The question is given manufacturing capabilities can the rod be made to the tolerances the program is capable of ackowledging.
Given the capabilities of CNC turning and grinding this accuracy level is rising. There need be only a minimum of polishing for a finished mandrel. The curves are created by the program and can be read directly by the CNC turning centers.
The FEA is run on the model created by the IPC program. This allows fine tuning of the program to be sure the parameters for the rod have been achieved. The mandrels can then be machined and the blank rolled.
As Owen pointed out this must then be verified by physical testing.
It does enable a very fast development of a rod for a particular fishing need with multiple iterations between IPC and FEA before commiting tools.

Eugene, it could have been what you are talking about. I really need to start paying attention in the classroom (lol). I think they may have been a little over my head any way. I haven't watched the video from St. Croix, but they use a cnc cutting machine from easton (the arrow people) that can make very exacting cuts for the graphite flag. The tech advances made in the last few years really amaze me, I think we are on the edge of some very interesting things to come.

There are already extruded graphite blanks but they are solid like the old glass blanks. Also there is a new material in the works that might be a carbon replacement called M5 fiber.

Owen: [www.rodbuilding.org]

NASA and the Military typically stay in advance of the sporting goods industry pertaining to the developemnt of new fibers. Many think the lead is approximately five years for the fishing rod industry. Work is presently underway to upgrade by some sponsors on this board.

Some interesting parameters come into play with pultruded blanks
1.
to be of any significant engineering value the minimum fibre length must be not less than 5:1 length to thickness.
2.
to be of any significant value in engineering a rod blank the longitudinal fibres need to be bonded with a thermoplastic that has both a surface & interstitial bondstrength that is equivalent to the elastic modulus of the fibre................such a thermoplastic/resin material does not currently appear to exist & is the next breakthrough in fibre bonding technology necessary for most of the' new' fibres to be applied to fishing rods.
The history of development in the fishing rod industry demonstrates the necessary link between thermoplastic/resin development & fibre technology for significant steps forward to occur.
3.
a technology to 'order' ( orient ) the fibres lengthways into the rod blank to be made, is also required................otherwise the blank is stronger in hoopstrength than necessary & heavier than necessary to get the required longitudinal strength\, in a pultruded injection moulded rod.

These are big hurdles to overcome.

I have been using pultruded carbon fibre rods in specific parts of some of my constructions for some 3 yrs..............they were sourced from the extreme Kitebuilding industry exponents. Excell Composites have been making this stuff for some time...............as have other specific manufacturers..................as a logical development of the pultruded fibreglass industry , which has been around for decades.
A number of pultruded die injection fishing reel bodies have used this pultruded carbon fibre technology for some time........................the issues experienced with those applications and their limitations clearly identify the key developments in the technology that need to occur before they can be applied to long skinny things like fishing rods, with any advantage .

Current developments are primarily in the adaption of long string fibres that can be manufactured and utilised in a similar manner to C/F in a pre-preg cloth.
I agree with Bill S the time lag between the aerospace industry and the fishing rod industry is about 5 yrs.

The issue for rod builders is that the more technically advanced the materials are that we use in our rods............the more necessary it is to understand the engineering implications of our constructions ( guidetrains primarily ) in order for us not to exceed the inherent properties of the blank .
Multi-modulus blanks are likely to become more common ..............we already see Kevlar reinforcement and different pre-pregs in use in different sections of different rods .................the issue for us as rodbuilders is understanding what this means to us, in what we do to that blank when we get our hands on it.
and
what we need to know about that blank, before we start constructing with it.

Denis,

You are obviously not privy to the latest advances in blank technology. They do not involve carbon fibers. Kevlar will not play a role. There is no prepeg involved.

...........

All very very interesting. Good read. I happened to be wondering about this topic recently. Couple of questions:

1 I'm wondering if any of you who are using a new blanks that is literally new on the market, whether you intentionally load a sample until it breaks to see how it will load until breakage?

2. If a built rod that has an obvious point in which the bend of the rod is significantly sharper at that one point than any other point on the rod, does that mean this is very likely a breakage point? We're talking high modulus graphite blanks.

Thanks,
Mo

Tom

Its pultruding technology...........identified in the first line of my response. Thought you would have recognised that.

Mo

1.
yes , Rod purchased for a particular anticipated load, test it at , at least , that load and replicate actual use conditions of load angles...............saves building a rod that will not meet the duty requirements.

2.
Absolutely certainly Yes. big problems can be seen in a std static test....................other dangers lurking in waiting not seen until other test variations are employed.
ie
a rod in real world use spends a lot less than 5% of its time under load in the shape seen in a std static load test.

MO, regarding question #1 - I try to fish all the blanks I build on, and push them to their limits. I've broken a couple, and learned that some of them I could push really, really far. The blanks I'm working on with Seeker, I have tried to break the prototypes, but there comes a point where it'sjust not going to happen: [northeastrodbuilders.com]

#2 - St. Croix MXF blanks have an extremely sharp point way out on teh tip of that particular series of blanks. Ergo, XFast action. If you are looking to create a problem where one doesn't exist, you can sa that is a possible breakage point - or you can look at teh real world and realize that there are thousands of those blanks & rods being fished right at this very moment, I promise you all of those guys will call that point the spot where the action shuts off (or something along those lines), they would not call it a breakage point.

Billy
The noticeable taper change you refer to is exactly the stuff Eugene is referring to I believe.
Some of those points are externally visible others are less easily visible.
any blank with a defined 'shut off' point effectively locks the deflection forward of that point.................conventional visual loaded rod curve examination does not identify the increased stress level that accompanies any additional loading beyond the "shut off " point.
any such additional load is focussed on the area immediately infront of the 'shut off' point. The stress is logarithmic relative to the increased load.
Where any such change in blank section properties occurs the angle of attack of the load and the guidetrain design there become critical.
To 'know' how to respond in your guidetrain you need either some numbers to assess the situation or fly by the seat of your pants.
and
Don't get me wrong.....................there has been a long history of successfully flying by the seat of our pants..............and some failures.................the issue here is how can we potentially optimise the situation & what do we need to know to achieve that.................thats all.

I look forward to Eugene's contributions on the subject.

My point has been, and Eugene even mentioned it in his first post - the blanks are not breaking, so what situation are you assesing? THere isn't a problem. THe rod has an XF action, thousands of people use the rod every day - if there was something wrong there would be hundreds of breakages. ou can spend days and weeks determining the oen millionth percent best place and best size guides for that particualr blank...and there won't be any noticeable difference whatsoever once people take teh rod out and fish with it. The rod didn't break before, it still won't break, it will still cast teh same, it will still fish the same.

Now, if you guys really want to spend some worthwhile time - you need to figure out a way to prevent breakages from feet, windows, and cieling fans. Then you'll be onto something major. I know that if you suply your customers with a pair of Crocs adn tell them to always wear them which fishing this rod, they won't be able to break them by foot. So I solved one problem for you guys already.

There was a time when rodbuilders would not build on 2-piece blanks & some still won't.
There is an engineering approach to the issue .............as one of the simple stress related applications

In the development of micro guides the objective & benefit is reduced additional weight on the blank for increased reflex velocity............from an engineering approach can we reduce the number of guides..............or will this lead to other issues...............how do we know..............one way or the other.

If we switch from one blank to another made from a different material , should I use the same guidetrain or another.
Only those with short memories forget the high level of breakages in the shift from fibreglass to carbon fibre blanks............why do we tend to have one more guide on C/Fblanks.
Is the guide spacing progression optimal...............how do we know.

In the evolution to the next blank fibre ................what do we do...............break a few before we get it right.................how do we know what to do.

There is a lot of attraction to a sound engineering approach to guidetrain design.

Whilst a blank manufacturer might use FEA and PCAD to design a blank action ......................did that FEA include guide forces ?????

John M
is the next fibre for fishing rods likely to be M5 (PIPD)................ I doubt it.
Why
Compression strength and compression strain are the key issues for fishing rods
M5 has just over 3/4 of the compression strength of Carbon fibre, but at the same time only just over half the compression strain capability of carbon fibre.
Its elongation is the same as carbon fibre , but is 5.5% lighter.
That means that nearly twice as much M5 has to be used to achieve the same resistance to compression failure as carbon fibre and the weight would be 80% or so higher than the same carbon fibre.
Is this a likely direction....................don't think so..................unless a further development of the M5 molecular chemistry can be achieved....................based on the published information currently available................. or the whole light weight market hype for fishing rods takes a radical change in direction.

There are a few other fibres around that have potential ................ the principle attraction to development of alternative fibres to C/F is the cost of manufacture and the high degree of process control required for C/F. The principle difficulty with a lot of other fibres is the low surface bond strength characteristic they exhibit in thermoplastic/resin etc.
Time will tell if further improvements in M5 (PIPD)can be made to make it a viable competitor to carbon fibre in fishing rods.