This step is where the shock cord is attached to both the body tube, and the graphite rotor shaft. The Rotary Revolution is a new competition style helicopter duration rocket. Specifically, this rocket is designed for use in FAI style competitions. The model meets the requirements of the S9 event, in that the rocket is 500mm long, 40mm in diameter for 50% of the length. What makes this a very competitive model is the lightweight hub that free-spins on the rotor shaft, and the lightweight balsa blades. I designed the hub for my daughter to use at the World Space Modeling Championships in Bulgaria this past summer, and she had pretty good results.