Emory,

I have a degree in that field. Trust me when I tell you that I understand it and know how to deal with it.

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Edited 1 time(s). Last edit at 09/03/2008 01:23PM by Tom Kirkman.

I have a large stash of blanks bought at the big rod expo the last couple of years. Many of them are two piece models. I hate to do it but you have convinced me it will be worth it. I'm going to take a couple and hold them at forty five degrees to the floor. Then I'm going to hang a bucket off the tip and have water added until the blank blows up. Then you can argue with the pictures I'm going to take and show that the rods did not break forward of the ferrule. I'll try to get to this tonight.

These threads remind me of Voltaire's observation: "Perfect is the enemy of good".

Bill,

You might want to ask yourself if it's really worth breaking blanks that could be put to better use. No, they aren't likely to break ahead of the ferrule, but so what if they don't? You're out the blanks and I doubt you'll change the opinion of those who disagree with you, me or anyone else for that matter.

I think Travis got the information he was after.

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I certainly got the information I was after. No need to destroy perfectly good blanks.

Tom,
If you have a degree in that field, I assume that you mean mechanical engineering, you no doubt kept your test books. Look in your Strength of Materials text and see what it has to say about stress concentration.

I know a great deal about stress concentration, moreso, I know how to minimize it and deal with it. If that couldn't be done, we'd all be in trouble - most of the world's infrastructure would have failed long, long ago.

If multi-piece rods were routinely popping ahead of the ferrule or failing in great numbers because of the ferrule, they wouldn't be making them. And, they're made in greater numbers today than at any time in history. Ferrules do not cause inherent problems and multi-piece rods do not break with greater frequency than single piece rods.

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I can unequivably state that I have had many dozens of times more single piece rods come back due to breakage than multi-piece.

My belief is that single piece rods are actually MUCH weaker.

Weaker than car doors, weaker than boat locker lids, weaker than tonneau covers, weaker than trim limbs, most assuredly weaker than ceiling fans ...

Multi-piece rods rule my personal collection and for VERY good reason. My only wish is that the general public would just try one good travel rod, with an open mind.



Edited 1 time(s). Last edit at 09/03/2008 07:28PM by Jim Gamble.

Tom,
I did not say that two piece rods routinely popped ahead of the ferrules or failed in great numbers because of the ferrules Those are your words not mine. The stress that is concentrated ahead of the ferrules is not large but if the rod is very highly stressed in the area of the ferrule it will fail a few inches in front of the ferrule, where the stress is concentrated. And a one piece rod does not have that same failure mechanism. Now if as you say you know how to deal with stress concentration so that is not the case you are genious.

Then there are a lot of geniuses around - they do it every day. I used to as well. If we couldn't, then many structures that serve us each and every day would not be possible.

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Hey Jim - I think you hit it right on!!! The point is that 2 pc. rods hold up every bit as good as 1 pc. under fishing conditions, and way better under travel conditions. If I had my way, I would build only 2 pc. rods. I look at it like 4 wheel drive on your truck, you don't need it every day, but when you do, it's nice to have.

Now, the real trick is how do we convince the general fisherman?????????

imo, the issue is not if multi-piece blanks are inherenty less structurally sound, but if ferrule design and manufacturing provides sufficient structural integrity to withstand the stresses that are incurred in the fishing for which the blank is intended - species and size, line & lure sizing, techniques, etc. And, accomplish this task without unduly negatively impacting other factors - action, weight, cost, etc. imo, ferrule design and construction from reputable manfacturers achieve this balancing goal (many exceed it).

As has been stated so many times, there is no reason at all to forego the additional advantages of multi-piece blanks. To continually to reinforce a "negative" based on the perfect analysis of structural properties and not to include in the observations the material lowering of the probablity of an incidence actually occurring imo does not help us serve customers as custom builders. As is the case in so many life choices multi piece versus 1 pc is a matter of probabilty. Not so long ago, it was a very high probability that an angler would not be completely satisfied with a mult-piece rod, but would endure the faults to get a travel rod (usually bought "extra" rods to get travel rods). Now, the probability that they will be completely satisfied with a multi-piece rod is the norm and not necessary to buy extra rods in the same length, power, action, etc - if they would only try a well designed and built mult-piece.

On the kick of stress concentrations-

There may be a slight stress concentration ahead of the ferrule. However, if it caused the rod to break under an applied load, then it wasn't designed correctly in the first place. It turns out that rods don't break unless abused- and sometimes they don't break when abused. There is a thing called "design stresses" which are > "actual stresses". Objects are designed using design stresses which take into account such things as stress concentrations. Apply a factor of safety and BAM! you have a unit built to withstand use + some amount of abuse.

Anthony