All Shafts have a Principle Plane of Oscillation
The subjects of Spining and FLO go hand in hand together when dealing with perfecting shafts for your clubs. The subject of FLO (Flat Line Oscillation) refers to how the golf shaft and is supposed to oscillate when loaded in your back swing through ball impact. All clubs experience some amount of oscillation during the swing. The goal of Flo Plane Orientation is to align the shaft and club head so that a straight line (plane) of back and forth oscillation is correctly placed in the direction of the ball at impact. A non-flat line consists of oscillation in a circle or an oval pattern, which causes the club face to wobble coming into impact and the golfer’s shot tends to spray.
Although produced by computer-aided precision devices and machines, golf shafts are not perfect. They are considered to be asymmetrical – not symmetrical. Symmetrical balance is when everything is perfectly and evenly balanced out. Asymmetrical balance refers to a design that has dissimilar elements but still appears balanced. Golf shafts are never perfectly round as there is always a small flat area on the cylinder (tubular) shape. This creates stable (strong) and unstable (weak) planes when theoretically dividing up the 360 degree circumference of the shaft into quarters on two planes of access. Imagine a circle evenly divided into four sections similar to a target sight.
Put simply, a shaft is a spring, which is affected by restoring force when load is applied to it. This is proportional to the amount of deflection and the stiffness of the shaft. Because the cross-section of the shaft is not perfectly symmetrical, then it will have a weak plane and strong plane. The purpose of FLO is to identify the most stable plane (as per SST Pure or the process of Puring).
Flo Plane Orientation starts by identifying the weak and strong oscillation planes on the shaft. The stable plane will provide FLO for the shaft during swing motion. A spine finder is used to find the natural bend point (NBP) of a shaft, and then used as a reference point to find FLO. The NBP is the weak plane and the strong plane (not necessarily the spine) is 90 degrees opposed. The stable plane should be installed to face the target.
When the FLO is oriented to (pointed toward) the target, this results in a more consistent center of face strike and repeatable ball flight patterns. There are quite a few theories about what causes misaligned shafts to result in bad clubs. Hence, it is possible to orient a golf shaft into the club head at a specific position to maximize its capability and performance.
If you play shafts installed in the factory, you run the risk of having a full flex difference between certain clubs due to where and how strong the spine is located. This is presuming that halfway decent shafts were used in the first place to build your set. Of greater importance is the need to profile and sort shafts prior to installation. Swing weight and frequency are a smaller part of the total equation anymore. To have a set properly built, you may benefit from Spining and then FLO. The top grade (also high priced) shafts designed and made today are very consistent in their manufacturing methods and specifications, so spining is of little value. Yet, the lower budget graphite and steel shafts placed into 2nd and 3rd tier golf clubs are of below average to poor quality and would perform better with Spining then FLO. Proper club assembly is so important and does not happen at the OEM level. It happens in the shops of Professional Clubmakers like us – who not only understand the theories – but practice them.
We have the tools to spin test by single degree increments – for FLO in disassembled golf shafts. A basic test can even be performed on finished clubs that can identify whether or not your club head oscillates in a circular oval pattern or the proper pattern on a linear plane towards the target. Obviously, a non-linear pattern indicates erratic behavior by the club when loading it and striking the ball.
NOTE: If you think that the major manufacturers FLO their shafts during mass production – think again. FLO orientation takes time and effort – which equates to higher cost. Supposedly, the graphics on a shaft, which face the golfer at address, place the strongest most stable plane towards the ball. This is simple not true in the majority of cases. In about 60-65% of shafts tested, proper FLO orientation was not correct with the graphics on the upside of the club shaft face.