I had this idea after I studied a tulip on my roof garden. In the morning the blossom opened, in the evening the blossom closed. If I forgot to water it, it let its head hang down. During the day the flower always tried to move to the brightest sunlight. The blossom is like a gripper, I thought, and the stem like a thin robot arm (maybe I should stop taking these drugs...).
However, next day I started to construct the robot prototype. The stem is made from a strong spring, a former toy RC TX antenna. The spring is actuated by a small cable winch. The cable winch is driven by a small geared motor and controlled by a magnetic encoder and a micro switch (position calibration at start up).
The gripper is made from 2mm ABS sheet and two small plastic gears and actuated by a micro servo.
The turn table is driven by a common unipolar stepper motor and has a micro switch on one of its two end positions for position calibration at start up too.
The next idea would be to construct a spring whose spring force could be electrical manipulated on different positions, so if you force it down, it only bent on according manipulated positions.