chgpa.org

Mount little pieces of semi-flexible wire to the sides of each cup, then mount a little goat or cow bell on an arm just at the far reach of the spinning cups. Sort of like clothes-pinning playing cards on the fork of your childhood bicycle. As the cups spin they lightly tap the bell..... Music when ...

It is actually the latest in drone testing.
The idea is to trick a terrorist into thinking it is a sport paraglider, then wham, a Coke bottle whacks them on the head and takes them out.