This is such a cool idea, using a delta robot to function as the print head for 3D printing objects.
Thingiverse user Johann is working on a new delta robot 3D printer prototype called Rostock. The Rostock 3D printer is 30 inches (77 cm) tall, and the build volume is 8x8x16 inches (20x20x40 cm). It uses 6 of diagonal rods that use universal joints and are fully printable. The print speed can be up to 400 mm/s in all three directions.