Tom, or others, would you please answer my latest four questions on the topic Kazillion Spine Questions so I can stop taking Zanax and go to sleep at night. I am kinda a newbie to this board and since the topic is now on page two....I don't know if anyone is going to read it. If my own answers are correct to those 4 questions I will have finally settled it in my mind.

Jim Williams

You're worrying far too much over something that has very little effect on your rod. In fact, if you just select the straightest axis of the blank and mount the guides there, your rod will cast and fish just fine.

I did go back and answer your final questions as best I could.

.........



Edited 1 time(s). Last edit at 05/13/2005 07:28PM by Tom Kirkman.

Jim,
There are a number of manufacturing problems that can result in one axis being a little stiffer than another axis. Any void in the blank wall such as an air bubble will result in a localized spine, the way the material is put on the mandrel will result in an overlap of material which results in the wall thickness being one layer thicker in one axis which results in a spine that often will spiral up the blank, any area in the blank where the wall thickness is a little thinner or thicker due to several manufacturing problems will result in a spine, if the blank is very slightly oval or elliptical in shape will result in pronounced spine, if the blank cross section is eccentric it will result in a pronounced spine, if the blank is not straight this curve in the blank will result in a slight spine. The sum of these in a blank is what we measure and call the effective spine.

There will usually be two soft or less stiff planes or axis that are almost always 180 degrees from each other, with usually only a very slight difference in stiffness between the two, and there will usually be two stiffer planes or axis that will also usually be 180 degrees from each other and 90 degree out from the softer planes and again with usually only a slight difference in stiffness between the two. The softer or less stiff of the two soft axis is normally considered to be the spine.

You can choose to mount guides on any of these axis or planes. Some advocate putting the guides on the effective spine, some advocate putting the guides 180 degrees from the effective spine, some advocate putting the guides on the plane of the cast which is usually 90 degrees out from the effective spine or on the stiffest axis.

It is my feeling that on very heavy off-shore boat rods that can sometimes have a very pronounced spine that it is probably a good idea to put the guides on the spine or opposite the spine, particularly if the rod is not spiral wrapped. If the boat rod is spiral wrapped or on most rods that will be used to cast it is not going to make much difference. The positioning of the guides on the blank and weight of the guides and the torque or lack of torque that result from guide positioning is going to swamp the effects of the spine.
I think that the advice that you have been given by others, not to worry very much about it is good advice. Personally on casting rods I mount the guides on the straightest axis and do not worry about the spine.

As far as measuring it is concerned, there are a number spine finders or static of techniques all of which will give you about the same results. There is also a dynamic technique that I feel is better than the static techniques because it will tell you where the spine is dynmically which is often a number of degrees off of the static spine. This involves mounting the butt of the blank on a stable surface like your work bench, deflecting the tip 8 or 10 or 12 inches and releasing it. If the tip of the blank tends to vibrate or oscillate in an oval after a few oscillations it is not oscillating on the plane of the spine. If you rotate the blank a few degrees and then repeat the process until the blank oscillates straight up and down it is oscillating on the spine.

I hope that this helps you a little.

Jim, stay on the ZANAX, as the spine is only the beginning of the rod building process.. You end up with the Color Change Weave !!!!!!!!!!!!!!!!!

Tight lines,

Art