I was just toying around with some blanks I have, and clamped the butt end of a blank in my chuck, used one set of rollers placed about 18 inches from the chuck. I locked teh chuck in place with the indexing pin, with the spine of the rod placed up. I pressed straight down on the tip, and released. I did this 4 times, every 90 degrees from what I found to be the most effective spine.

On some blanks, the rod would oscillate straight up and down. On others, it would go up and down, then in an ellipse, into a circle, and then back into a straight line, over and over again. On the blanks where it oscillated staight up and down with regards to the spine - I think that is a good thing. I will cast, and the tip will move straight up & down. I assume this will increase accuracy and distance (not for me the way I cast!!)

Now on the rods where it would oscillate all over the place, I feel these blanks will not cast as far or accurately as the others. Am I overthinking again? I remember Don Morton doing this at the National, but since my brain was already full with all the other iinformation he was giving me, I do not remember what he was trying to achieve by doing this experiment.

Although I am building Inshore Saltwater rods, where distance and accuracy aren't really as important as in other types of fishing, I feel I should at least understand how to further refine my rods in my quest to build the "perfect" rod each time i build one.

I sometimes get the feeling we over do things: the weight of an underwrap being too heavy, sensitivity issues, this whole post, etc. But I also feel this is what makes the "perfect rod". Maybe I will gain only an extra 1 foot of distance, or save 1/8 ounce in weight, or feel the bite 1/1,000,000 of a nano second sooner - but I know in my head I am fishing with the best possible rod I can build.

Billy

Billy,

What the rod does when clamped to a table is not what it does when cast by hand. These types of tests do much to tell us about the inner workings of the blanks, but often have little to do with what happens out on the water.

In the meantime, I'm sure Don will weigh in with his opinion. He has done similar tests to what you have done and reached his own conclusions.

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Tom is correct Billy. What you have found has much more to with the very finest make up of a rod than what really hapens when you fish with a rod. The guides don't have to be placed related to the spine and the guide spacing don't have to be any certain distance apart for a rod to catch fish. Take the average rod off the shelf, it is not usually spined or set-up using the criteria of a custom rod builder but people fish with them. The custom rod builder is concerned with building a better rod or perfect rod, that is the difference. If you are looking for an average rod buy one at the cheepest price you can find at the discount store and that is what you will have, the cheepest rod you can find.

Off my stump, Yes the rod will vibrate in different patterns depending on the blank and the position the rod is held in relation to the spine and probably many other factors. In my opinion the more we look at these factors and apply them to the construction of a rod the better rod we have produced.

I'm no expert and could be way off base here but it is my observation that most modern graphite rods don't oscillate when you cast them. At least not for more than a split second. I think what is causing the long term oscillation when you clamp it to a table is that there is nothing to bleed that energy off so it just sits there and vibrates. It won't do that when you cast by hand as it is not attached to a fixed and stationairy object.

I had been building my rods with a guide on the nodal point until recently when I realized that today's high performance blanks don't oscillate or vibrate like the old ones did. The nodal point only comes into play if you sit there and shake it back and forth, which you don't do when casting.

I'm going to weigh in on this and I don't know squat. One has ones auto tires "balanced" in order to tune out inconsistancies in the construction of the tire and wheel, the same thing is done on the fans of fan jet engines. Seems to me that if one turns a blank that is properly supported what is really being done is a "quality check" of the blank, One must,however, bear in mind that an object that is spun about its axis has a "natural" vibration range which is normally at lower rpms; in fan jet engines its known as resonance, Since rod blanks aren't designed to be spun it's difficult to know what that range is. As someone astutely noted stiffer blanks like graphite don't wobble as much as glass.
I do wonder,however, if one were to mark the stiff and soft points on the blank if they would correspond to the points of least and greatest flex?Just some commentary from the "Resident Dummie".Warren

I did this same thing a while ago and thought what a wonderful demonstration of the effect a spine has on rod stability. When deflected along the axis of the spine, oscillation was in a straight line. When deflection was in a plane out of the spine, the tip would oscillate in an ellipse or circle. It did this with about 5 flyrod blanks up to 6 weight. I then made the mistake of trying the same experiment after the tip was mounted. That small amount of weight from the tip negated the effect of the spine. The rod would oscillate in a straight plane irrespective of the plane of the spine.

Thanks for all the responses. While Graphite is stiffer then glass, and thus resists "wobbling", I did this on composite Graphite/Glass blanks. John - the wierd thing is that one of the blanks would not osillate up and down, regardless of the spine. I guess the guides would negate this though - never even crossed my mind while I was experimenting.

Good points made by all, thanks. Billy