Well your probably right....but don't blame me, I didn't coin the term! I don't think the term "lockup" is scary, or wrong....it's just a term that has been used for a long time to describe a specific anomolie in a blank.

Actually now that I think about it, Power Point is really a pretty good way to describe it.


Andy Dear
www.lamarfishing.com

Guess I got to yell at Tom ?? LOL

OK, so the other day, I was fooling with a rod I was about finished with and I accidentally found the Lock Up point and proceeded to then find the Break Point which was only slightly different in load! I am like Bill, I dont get it. If I take a very limber rod (boy there is an old term), and I add more and more load to it, it seems to me that it bends until it cant bend anymore and then it ruptures BECAUSE it cant bend any more. You get to a point where the allowable stress and the load are equal and with any more load it must fail. So is the Lock Up Point and the Break Point the same on some rods?
I am lost.

You just bent it toooo much, and way over loaded it. Bend you too much and you will break also LOL

Well I suppose it can be if you stress it incorrectly. Then again you can break any rod if you stress it so acutely that it hinges. I think the key is to stress the blank "through" the lock up point and not stress it so acutely that it "hinges" at the lock up point. When I was a kid, my old man used to jump all over me when I was fighting a fish..."KEEP YOUR ROD TIP HIGH" he'd say....what terrible advice! If you keep your rod at a high angle under a severe load it will break obviously. But if you stress it through the tip, so that the tip straightens and the load is on the butt, it's a different story altogether...at least that's how I look at it.
That's why guys who fish big tarpon with (flyords especially) keep their rod tip low and stress the rod such that the tip/mid straightens out , and the load is on the lower mid/butt.
Rich Forhan's article on guide placement sort of alluded to this. He was measuring the amount of force put on a single foot guide to see how much it would withstand before it pulled out of the wrap. What he ended up finding was that there is actually very little force on the tip guides, because on a rod stress correctly the tip actually straightens out and the load is transferred further down the blank.

Andy Dear
www.lamarfishing.com

What I wanted to add on my last sentence was:

"On a rod stress correctly the tip actually straightens out and the load is transferred further down the blank, usually past the first lock up point"

Andy Dear
www.lamarfishing.com

As in so many things, certain terms have their own distinct meaning when used within certain applications. A gamble who is "sweetening the pot" isn't putting sugar into a pot. He's adding more money or making something more lucrative.

Same with the terms "shut-off" or "lock-up" in rod building. Technically a rod would never stop bending if you keep applying more and more load to it. But on many stand-up blanks, you will find a place where the blank suddenly requires an exponetially greater load on it for the flex to continue as it had been doing prior to that point.

If you or anyone else has a better, more intuitive term for this sort of thing, let's hear it. If it's good, it will catch on.

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

Boy, Boy it sure would be nice if we could get some of the blank engineers/designers to comment on this thread. Werefore Art Thou - Todd, Jason and anybody else who actually sets these things up or designs flag patterns. It would seem to me that anyone defining a "lock up point" could better describe this effect as a zone of transitional deflection arc change due to applied stress. Somehow lock up point or lock up points just does not tell me anything that will help me describe or sell a popping rod.

Stephen Pratt is already aware of this post and will be weighing in shortly with me. I'll post his response here.
Bill, I think your over complicating this thing.....it's not meant to be used as a selling tool, unless you choose to use it as such. It's just a term to more accurately describe the action of a particluar taper....that's all.


Andy Dear
www.lamarfishing.com

I have used this term for many years to describe to the customer the location on the blank where the flex finishes and the power really takes over. I like Andy's description from CTS. That is pretty much what I use all the time. Logically it varies from blank to blank but it is still there whatever blank you use. Most customers will explain what type of blank they want and they can understand the term "lock up point" better than some other fancy yet less description terms. The CTS system is what they refer to as a Triple Taper system.

Regards
Mark Fisher

Mark...exactly the Triple Taper System....I didn't want to get into that and confuse the issue further. However, that's the reason for the 2nd lockup further down in the blank.


Andy Dear
www.lamarfishing.com

Thanks Mark for your comment. If a rod used for "popping" is typically one normally called moderate action by most where would you expect the "lock up point or points" to be approximately located on a seven foot blank. Can one blank be said to have a better lock up point than another for the same general technique. If builders can better describe a particular blank by the location of lock up points how would you go about doing it. Is this a term that could be used to say one blank is better in any way than another?

Tomatos -- Tomotos I still think Power Point explanes it better --IMHO

Multiple lock up points??? Why would anyone want a blank that had multiple points where the stiffness rapidly increased. Why not just have the stiffness increase uniformly and rather than have multiple points were the blank's stiffness increased very rapidly over a short distance and just make the stiffness transitions more smoothly. Abrupt changes in stiffness will create points where the blank is more likely to break under load plus the blank will not cast or handle fish as well with abrupt changes in stiffness.
I can understand how it might make sense with a heavy boat rod to have a point where the stiffness increased fairly rapidly but I do not understand it with any other type of rod. Someone will have to explain it to me and in terms that are more than just marketing hype.

Where the blank locks up or shuts off would have nothing to do with one blank being of better quality than another, or being better than another (unless you need that point to be in a specific place for what you're wanting to do). A fast action is not better than a slow action, unless your particular requirement demands that you employ a fast action rod. Then it would simply be better for that particular purpose.

On short stand-up rods you do not want a rod that will flex deeply into the handle. If it does, you will not be able to keep the rod tip far enough out over the gunnel. You have to have at least some minimum amount of length that doesn't flex - that stays "out in front." Many stand-up type blanks are made this way and for this very reason. If the rod folds or flexes all the way into the reel seat under the max expected load, you aren't going to like it very much. I can promise you that.

I think many customers may actually be referring to something else, however. Generall, if you take a rod blank and flex it until the tip is at 90 degrees, you can then look at that initial flex and see if the blank is fast, medium or slow in action. When you have the blank at the point where the tip first hits the 90 degree mark, the portion of the blank that is still straight could be considered the lock up point. I suspect that is what your customer was referring to.

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

I think Tom and Andy's descriptions fit pretty well, except that many rods will start shutting off well before the tip angle hits 90 deg. The lock -up or shut- off refers more to the deflection shutting off, but you could call it the onset of the power zone from that point of view as well.

Emory, The shut off is distinctive, but it's more of a transition into another zone rather that a sharp or sudden point. Take a look at this graph I made of a power vs. deflection for a Loomis fast action.

[www.cptelecom.net]

The plot on the right of load (power) vs. tip deflection shows two linear regions with a transition between them. When the rod is initially loaded, there's a linear region up to a point at which the rate of deflection slows and the power transitions into a zone with a much higher slope. If you look at the values, I was able to get to 30% deflection with less than 500g, yet it took more than 1000g to generate another 20%+ deflection on top of that. Beginning in the transition region, the rod deflection starts to slow or shut down (not really off) , and the rod will require a significantly greater load in order to generate further deflection..... further out in the power zone the tip will eventually go to 90 degrees, and somewhere beyond that it will break. In this case, I'd define the shut down, or lock-up point at that zone around the 35% deflection where you'd feel a distinctive transition in power. If you extrapolate lines tangent to the linear regions, you'll find that corresponds to the same region where the tip rolls off in the plot of tip angle vs. deflection on the left.

mark

Mark,
That's EXACTLY what I was going to post next was that the "lockup point" is a transitional zone that allows you to access greater power in a different area of the blank, without sacrficing durability like you would if the transition was a "sudden or sharp point as you put it" I think that's where some folks are getting leary of the term "lockup". In my previous post I mentioned that the lockup zone is actually several inches long, and not just a "point"
In many cases, one can look at a cut flag pattern prior to layup and see exactly where the lock-up will occur.

Maybe we should modify the term to "lockup zone" instead of "lockup point" this would infer a wider area of transition as opposed to a specific point, which I think people would grasp onto better.

That was a great post Mark., and you should be comended for being able to balance the technical jargon with the layman's description.


Andy Dear
www.lamarfishing.com

Mark,
I guess I do not see any "lock up point" on your graphs. "Transition into another zone"? I am sorry but I think that is as bad as "lock up point". If you would have labeled your curve force on the vertical and deflection on the horizontal it would be a curve of stiffness, stiffness being the slope of the curve. I guess what you are calling the lock up point is the point on the curve where there is a significant change in the slope of the curve or a point of inflection. But maybe we are just debating the meaning of words now which I guess is probably not going to get us anywhere.

I think I have the information that I originally needed. Generally the quality of a blank is not determined by the number or positions of lock up points. I guess the guy who stood there shaking a blank and commenting on lock up point was using infomration based upon shaky ground to start with. Maybe everyone will think twice before using this concept to compare quality of blanks of the same action type.

Bill,
Lockup points have nothing to do with quality at all....it's just what it is, a performance aspect of the blank. Like Tom said, a slow action blank is no better than a fast action blank...just different.


Andy Dear
www.lamarfishing