Polyrhythm drum - Exploring patterns in cyclical systems.
Photo credit: Sandra Ciampone
Two suspended vibration motors oscillate against the surface of a central body. When the motors fall, they come into contact with the rigid face of the object, and the energy they exert pushes them back into motion. Slight discrepancies between the mechanisms of the motors cause them to oscillate at varying heights, such that they drift in and out of phase.
Photo/video credit: Sandra Ciampone
Method
The bounce height of the two motors is dependent on the alignment of their cycles with the moment of surface contact. If the motors land when they are travelling downwards, there will be a greater impact and resultant repulsion force.