This Delta Robot is made from ply wood and aluminium. Cheap servo motors for the positioning. Atmel Attiny2313 for controlling the servos over RS232 with MATLAB. MATLAB calculates full inverse kinematics for the robot. The robot moves to given points. The point-to-point movement is realised with linear interpolation and inverse kinematics.
How does the inverse kinematics work? Look here: http://forums.trossenrobotics.com/tutorials/introduction-129/delta-robot-kinematics-3276/ or here: http://www.cm.mcgill.ca/~paul/clavdelt.pdf