Giandomenico De Sanctis made a really clever robot arm, source and schematics included – “I am always been interested in the construction of robotic equipment, but I have no mode to make anything… until now! Some months ago I saw the movie “I, robot”, and I decided: it’s the moment! I want to build a robotic arm! Here I present the results, hoping it would be useful to other people also interested. This robotic arm is a little demonstrator, it uses stock servomotors normally used in RC models, and it’s controlled from a pc, attached with a serial cable.” Link.