Here is a cool robot arm that can sort LEGO parts by size and measure the number of teeth for each gear. You are going to need parts from LEGO MINDSTORMS EV3 core set 45544 to build your own robot arm. Just provide the robot with parts and press the appropriate button to have the robot do the rest.
More gadgets like this: here
Mysterious Gear Sorter
Like what you see? You can buy the building instructions here.
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