The effect of guides on spine is hard to evaluate, if it can be.
Merlin,
I agree that analyzing the overall effect of varying scrim overlap on a rod section would be difficult if not impossible since the only way to know how much overlap there was at a given point in the rod would be to cut through different cross-sections as Dr. Spolek did in his spline paper.
That is why Tutleman (and I for that matter) find it amazing that something as complicated as spine can be accurately modeled with a simple quadrature spring model.
The important FLO is the one of the butt as demonstrated by Graig Spolek, and you can rotate NBPs of other sections to minimize bending assymetry which is important to avoid lateral deviation of the tip.
And I think that Tutleman's FLO approach provides a way of doing such a dynamic spine alignment in a straight forward manner.
I would start the process by aligning the weak FLO plane vertically. Then I would align the other sections with their strong FlO plane oriented horizontally. Thus the weak spring constant of the butt section would be added to the strong spring constant planes of the upper sections. That would tend to minimize the different of the spring constants in the overall rod and thus reduce the net spine of the rod.
I still would not want the rod to twist when fighting a fish so at that point I would put the dynamically aligned section in a static spine finder, add a significant mass to the tip and let the rod spin to its static neutral bending plane (NPB). I would expect that unless the rod had severe curvature the amount of that spin to the NBP would be relatively small since you started with the stronger butt section aligned to its weak FLO plane. Then I would put the guides on the bottom of that NBP plane.
If the guides add much stiffening (and Spolek thinks the amount of stiffening would be insignificant) they would be one the weak FLO plane of the butt and the strong FLO plane of the upper sections. Thus any stiffening they added would further reduce the overall spine in the rod, and yet you would have no twist when fighting a strong fish.
I am not convinced tip whirl is a problem since the tip will tend to follow the pull from the line but the above approach should minimize it.
Tutleman is adamant that spine finders should not be used to properly align golf clubs. As he says (and his comments would also apply to fly rod blanks)
What happens when there is both spine and residual bend? Unless the spine effects are large enough to overwhelm the residual bend, you will get spine and NBP directions that do not conform to the laws of phyics -- and therefore are wrong.
FLO finds the real spine and NBP, unpolluted by non-spine properties like residual bend.
Because conventional, bearing-based spine finders are not a reliable way to find a spine. They are thrown off by any residual bend in the shaft. If the shaft is very straight and has a lot of spine, then they will give the right answer. But, for most shafts, the residual bend is enough to partially mask a modest spine, and the spine-finder gives the wrong direction.
I would be interested to see if people are using a different approach to minizing the overall spine and rod twist when building a rod. I am a convert to Tulteman's FLO approach. With a high speed camera it is easy to measure the vibration frequency to find the strong and weak FLO planes then it just a matter of using the above approach to get a finished rod with the least amount of overall spine and rod twist.
Gordy