Spine and FLO plane

[byerxa]

I built a spine finder over the holidays (like a NF2 but cheaper) and sure enough it does a good job of profiling a shaft (steel at least). However, when I attempt to FLO analyze the shafts, things are not so clear cut. I built a cheapo rig where I clamp the butt end and put a ~200g rig on the tip with a laser pen. I then twang horizontally to try to find the FLO plane. This has proven difficult to do and required much practice. I eventually got a "feel" for it and seemed to be able to identify the FLO plane. However, in 2 Rifles I did the FLO plane appeared to be almost 20-30 degrees off perpendicular to the spine/NBP plane. The 3rd one I did was almost bang on 90 degrees. For the real club makers out there, how far off have you seen the FLO plane from the expected 90 degrees from the spine plane in steel shafts? What is the average you have seen? I am really suspecting my methodology here so I am looking for some feedback.

[Chieflongtee]

I have not seen your jig therefore I do not know if you are doing FLOing correctly. All I can tell you is that what you are finding in your spinefinder(bearing type) is not a spine but rather a residual bend also called out of roundnesss or not symmetrical. There is not such thing as a spine 180* from the NBP. There are 2 planes in alll types of shafts 90* from each other. That is why FLO does not jive with your findings.
Anyway steel shafts are not even worth aligning as there is hardly any difference between the soft and hard plane(1-2 cpms). I would suggest you read the following from John Kaufman's web site. http://www.csfa.com/techframe.htm

Wobble



NOTE 3: If you get into the hairiest of mathematics you'll find any shaft has two natural frequencies and they are always located 90 degrees apart on the shaft. At one point you will get one of these frequencies and by rotating the shaft 90 degrees you'll get the other. If the shaft is flexed anywhere in between both frequencies will be excited and the two will beat against one another causing the shaft to wobble. The two frequencies in a steel shaft or a filament wound graphite shaft are generally very close such that very little wobble will occur. In wrapped graphite shafts this is not always the case due to the seam and wobbling can be pretty wild. I've seen as much as 12-cpm difference between these two frequencies in some shafts. If a shaft is regular along one axis and stiff along the other how do you install it in the club? It's best to buy good shafts. Again the frequency analyzer is a great quality control device. By the way, that vibratory gyro I mentioned in an earlier Tech Note had its two natural frequencies matched to a small fraction of a part per billion. Like I said it wasn't a cheap device

[BC MIST]

If you can sight down the shaft looking into a light bulb and actually see a bend, or feel a hard resistance in your spinefinder, don't use the shaft. Otherwise, align the shaft in the head any way you want it as any spine that it has will have negligible affect on the club's performance. I have installed roughly 120 Rifle shafts in clubs in the last year or so and they are very well made. It's the True temper shafts that I have found to have a lot more bends in them.

If when FLOing your shafts, you come across one that ovals very quickly, either don't use it or just keep turning it until you find a flat line. Mark that point and align it to the target or align a point 90* from the original point, to the target as any spine is always 90* from the NBP, as Andre says above. You will still hear a lot of clubmakers say that the spine is 180* from the NBP, bit this is not so. Use of a frequency analyzer will confirm this.

I find that when using my NF2 with graphite shafts, it does find the NBP, if one exists, and the "spine" is almost always 90* from that NBP as determined by FLOing. I think it is really essential to FLO all graphite shafts. Some companies like Mercury and SK Fiber, are producing excellent shafts and other manufacturers are slowly catching up in their quality control.

[byerxa]

I realize the term "spine" is a misnomer (throw back to before my time!) and I am actually finding the residual bend planes. I was just curious if it is reasonable to see a FLO plane that far off perpindicular from the residual bend planes. I am seeing that doing all of this with a good steel shaft like a Rifle is probably a waste of time. Of 4 Rifles I have, 3 had definable NBPs, while the fourth was almost non-existent (although still there). Consequently when I do my FLOing it takes a lot of trial and error to really find a plane that is flatter than others. However, I processed a TT TX-90 R flex wood shaft I had lying around (I hate them) and it snap/spun so quick in the spine finder it was scary. I have a few other TT DGs around that I will experiement with to gain more experience.

Next month some time I will be re-shafting my fairway woods (UST ProForce 65s suck in fairway woods), and I am leaning towards SK Fiber LR Is. That will be my first run with graphites doing this.

Thanks for the feedback guys!

[BC MIST]

I realize the term "spine" is a misnomer (throw back to before my time!) and I am actually finding the residual bend planes. I was just curious if it is reasonable to see a FLO plane that far off perpindicular from the residual bend planes. I am seeing that doing all of this with a good steel shaft like a Rifle is probably a waste of time. Of 4 Rifles I have, 3 had definable NBPs, while the fourth was almost non-existent (although still there). Consequently when I do my FLOing it takes a lot of trial and error to really find a plane that is flatter than others. However, I processed a TT TX-90 R flex wood shaft I had lying around (I hate them) and it snap/spun so quick in the spine finder it was scary. I have a few other TT DGs around that I will experiement with to gain more experience.

Next month some time I will be re-shafting my fairway woods (UST ProForce 65s suck in fairway woods), and I am leaning towards SK Fiber LR Is. That will be my first run with graphites doing this.

Thanks for the feedback guys!

You will find an occasional shaft where the FLO plane is well away from the residual bend. I guess that it just means that the shaft is bent a lot, ie., snap in the spinefinder.

I have used the SK LR I's for a couple of years now in my own woods and those of a few others, and it is an excellent shaft.

Interestingly, I profiled a LR "R" flex and a LR "S" flex. In the butt end the "S" was stiffer by 13 cpms, which is logical, however, in the tip end, the "R" was stiffer by 8 cpm's. Now, the stiffness of which end of the shaft would have the greatest affect on performance? It is obvious that profiling shafts will be of great value in the fitting process, at some point in time, probably by the end of 2005.