Learn more at:
http://www.instructables.com/id/3DPr...

This robot arm is made almost entirely of 3D printed parts that snap together. It has three servocontrolled joints, plus a rotating base and gripper. The arm is controlled by a series of buttons that connect to an Arduino Uno hidden in the base. A simple circuit makes connecting the servos and buttons to the Arduino easy and makes setup and assembly very quick.