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Two of these mechanisms would be used for each side of the robot and the input crank shafts would be offset by 180 degrees from each other. This means that while one claw is engaged with the rope, the other mechanism is resetting to the top to re-engage the rope. Additionally, a copy of these two mechanisms would be reflected across the line of the rope so that two claws are engaging the rope at a time to provide better attachment to the rope. A top view of one half of the robot can be seen below along with the gears and sprockets used to transfer motion from the motor to each claw:
