Based on the original design for a delta robot by Reymond Clavel, the double and triple delta robots designed by Dutch inventor Aad van der Geest could have applications to the 3D printing sphere. According to the developer, his lightweight and versatile design overcomes the major limitation of most delta printers; a limited build volume area. By using articulations on multiple axes, the van der Geest design purports to be capable of a greater range of motion than standard delta configurations. You can read more about the design here: http://3dprint.com/32873/triple-delta-robot-3d-printing


Below is a photo to show the potential scale of van der Geest's design: