Axel32 of Let’s Make Robots! built this nice-looking SCARA robot arm with computer vision capability for about $40. A SCARA robot consists of a multi-jointed arm that is more rigid in one direction (the z axis) than the others (x and y), which makes it particularly suited for dealing with assembly processes where parts might not be lined up perfectly and a bit of compliance is necessary. Axel’s version uses the usual Arduino and Processing suspects to create a pretty sophisticated looking machine that can pick up objects by clicking on their picture. He has hopes of taking it with him on the job to perform repetitive tasks, that sounds like a great idea to me!
Homebrew SCARA robot arm