Jose Julio developed AHRobot air hockey robot from 3d printer parts. AHRobots vision system is made from PS3 Eye camera powered by code in C combined with OpenCV (open source computer vision) libraries for capturing, thresholding, filtering and segmentation..
GitHub repository with all the files, code and manuals:
https://github.com/JJulio/AHRobot
Project homepage with more details:
http://cienciaycacharreo.blogspot.com.es/2014/02/new-project-air-hockey-robot-3d-printer.html
Jose also made B_robot, fully 3d printable self balancing robot:
http://diy3dprinting.blogspot.com/2014/02/b-robot-fully-3d-printable-self.html