The Adaptive Shuttlecock is larger than regular shuttlecocks and it moves more slowly through the air, in fact the adaptive shuttlecock is an unpowered drone.

This is a tennis ball with three long eagle feathers coming out the back of it, and a spring attached to it, that stores energy. The spring should be weighted correctly, shaped in an adaptive sprial with the center being tight and a gradual loosening, and tuned to perfection, in the research stage, and then permanentized by making the whole thing out of one material or adaptively fading one material in the the next, so that the spring would be iron and the feathers would be something lighter and the iron can be printed to fade into the other material, so that there are no articulations.

The spring will store energy imparted to the tennis ball when it is hit by the racket, and distribute the energy adaptively to the feathers which will be flapping back and forth at the same resonance as the spring.
-- JesusHChrist, Nov 26 2016

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