|Wheel and Pendulum 2 (1970)
In 1968, I decided to investigate the kinetic relationship between a
pendulum and a wheel driven by it. I screwed a rod into my studio wall
as hanging point for a pendulum, attached a model airplane propellor to
a small electric motor (slot car type) to its lower end.. When spun,
propellor's thrust would pull the pendulum parallel to the wall but out
of plumb. The electricity to the motor was interrupted by a mercury
mounted on the pendulum when the pendulum was tilted so. This negative
feedback allowed the pendulum to swing back to vertical which would let
electricity flow again pulling the pendulum out of plumb. Thus, the
would swing at a rate determined by its natural periodicity, its
overcome by the rhythmic thrust of the propellor. Transferring the
momentum to a wheel via a spring caused the wheel to spin and interfere
with the pendulum's natural periodicity. Adding passive pendulums and
spring-linked wheels produced complicated behaviors.
The interplay between potential and kinetic energy was fascinating. I tried to balance pendulums' periods and wheels' momentums, varying the springiness of pendulum-to-wheel connections, adjusting pivot points on the pendulums and the wheels and counterbalancing the pendulums to produce behaviors that were nonrepeating. These systems of multiple pendulums and wheels could settle into a rhythm of movement for relatively long periods of time but then suddenly behave erratically for even longer periods. Sometimes they would change rhythms. A single arrangement could have several rhythmical behaviors and move from one to another, punctuated by random behaviors.
Years later, I was reminded of these patterns as I read about chaos theory with its strange attractors.
WHEEL AND PENDULUM 17(1971)
Double loop Feedback Tower (1972)
Collection of Allan Stone
Besides being free-standing, the tower was different from the Wheel
and Pendulum series, in that it consisted of two interrelated wheels
pendulums. They were connected by having the mercury switch that was
by wheel and pendulum A control wheel and pendulum B and vice versa.
is the "double loop feedback" of the title.
When I finished this piece. I was ready to attempt once again an artwork that would use a stimulus outside itself.
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