Conventional shafts are made of these different pieces because it’s a way to change the profile of a shaft. For example, stiffer material may be added to the tip section of a shaft to lower trajectory and reduce torque. But as each piece is added by hand, the shaft becomes more inconsistent. One reason for this is the margin of error that exists even for the most experienced shaftmaker. The second reason has to do with the orientation of the shaft fibers and how they change during the roll-wrapping process.
Think back to the example of gift-wrapping a megaphone. As you wrap the paper around the megaphone, the angle of the paper changes as overlap occurs. The same thing happens when you wrap shaft material over a mandrel. Because the mandrel is tapered like a megaphone, the orientation of the fibers changes as the material is wrapped around it.
To control torque in a golf shaft, for example, the most desirable fiber angle is +/- 45 degrees. This “X” orientation increases torsional stiffness, thus reducing shaft torque. As a general rule of thumb, the more +/- 45-degree angle fibers in a shaft, the lower the overall shaft torque will be.
The problem is that in the roll-wrapping method, fiber angles can shift 10 degrees or more by the time they’re wrapped all the way around the mandrel. This weakens the material, and the fix is to apply additional layers of material to create the desired stiffness. And as you add more layers in the roll-wrapping method, you also add more areas of overlap, which further reduces consistency and performance.
When we were developing TPT shafts, we knew we didn’t want to leave any room for human error. We needed to create a manufacturing process that would allow us to maintain the precise orientation of our fibers around the shaft.
That’s why from the start, a fully automated method was the only choice. The manufacturing of our shafts had to be driven by advanced machinery and robotics. That way, we could ensure the consistency of every shaft we made and create a new standard of performance.