Thanks to Tom Kirkman and Don Morton for their help with my issue but things look worse now at least to me. In following Don's direction to flex the blank with the guides in the up (on top) position, I decided to make a wooden jig to hold the blank while flexing it. I got even more creative and took two bearings, stuff them into a plastic sleeve, clamped it to my jig to hold the butt end so the entire blank could "turn freely" while it was being flexed.

I also discovered not only did the tip section have two spines 180 degrees apart, but that the 2nd section did as well and it is somewhat noticeable in the 3rd section (butt section is too stiff to tell). With my designated spines aligned, the blank WILL NOT stay steady with the spine on the top or on the bottom. It will jump back and forth to either soft spot between the two spines. And when flexing the blank while in the "fishing position", the tip top just jumps to one side or the other.

Then I got to looking at the white spots Sage puts on their blanks to indicate where they recommend the guides to be placed. I dug out my gadget I used to check my arrow to broadhead concentricity (another hobby) and these dots are on the straight section of the blank that will droop slightly down in the fishing position. The dots on the 2nd section are extremely close to "my indicated spine" and the tip and bottom two sections are slightly off.

I realigned the sections according to Sage's dots and with the dots on the top side, the blank would still roll from one side to the other. HOWEVER, when I flexed the blank with the dots in the down or fishing positon, the blank seemed to "lock in" and become extremely stable.

I value everyone' expertise on this board but this blank really scares me. With one spine directly on top of the other of almost equal strength, it feels like I'm trying to balance a knife edge on a marble with this blank.

If I should put the guides on what I think is the spine then I'll do it, but where Sage says to put the guides is really looking good to a dummy like me! If there's any more suggestions to try I would appreciate it. Thanks.

The soft spot is the spine. The locations where the blank wants to kick or jump are not. You have confused the position known as the effective spine with that or those points where the blank wants to jump or kick away from. The effective is found when the blank jumps or kicks and then comes to rest. The outside of the curve while it is at this place of rest is marked as the effective spine.

Sage has their spots on the straightest axis. Most manufacturers build on the straightest axis.

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Edited 1 time(s). Last edit at 12/20/2004 03:24PM by Tom Kirkman.

I have no idea what I'm doing then - I know less right now than I did before I heard a spine ever existed. I think I'll put this blank on @#$%&!

Dummy Rod Builder

There's nothing wrong with your blank. Go to the FAQs page and read the short bit on rod spine and how to find it.

Many people look for the place where the blank kicks or jumps thinking that's the spine - but that's not what you're looking for if you're looking for the spine. You're looking for the place where, when you stress the blank (flex it) it naturally spins to and wants to stay put. Any attempt to move it out of that position only causes it to return to that position. When the blank is in that position, the outside of that curve is referred to as the effective spine.

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I think there is far too much enphisis put on building a light rod on , or in refrence to the spine . I personaly put the sections on a flat , hard surface, tip up , 45 degrees to the floor , push down in the center , let it spin where it wants to , mark the inside , and place my guides on that plane ( fly,spinning ). That's it , done in 5 min. heavier rods for boat and such get some more attention to where the spine is located . John

Tim,
Part of your problem may be that the spine on many blanks will actually rotate slightly as it goes up the blank. It does not run directly up the blank or exactly parrallel with the center axis of the blank. This means that as you apply more and more force the spine will tend to move a little. In other words the spine will tend to be in a little different location when the blank is deflected different amounts. This may be part of what is happening to you as you first deflect a section of the blank and then deflect several sections together.
My suggestion would be to assemble the sections of the blank, get it reasonably close and then do not worry about it. As was suggested by several others, there is way too much heat and smoke dissapated over the spine.

THought Sage was better then that??? Hay, for the price??

Tim I think that Tom gave you the information you needed. I did not understand what you thought was the spine. The place where the rod comes to rest and resists turning is what you are looking for, not the place where it tries to turn or pops/snaps to one side or the other. Go back and repeat the process you did before and try to get the rod to a position where it resists turning. You are not far off.