Cornell University researchers have come up with an interactive prototyping system called “On-the-Fly Print” that prints what users are designing as they design them; the designer can pause anywhere in the process to test, measure and, if necessary, make changes that will be added to the physical model still in the printer. The new system uses an improved version of the “WirePrint” printer developed in a collaboration between Guimbretière’s lab and the Hasso Platner Institute in Potsdam, Germany. WirePrint aimed to speed prototyping by creating a model of the shape of an object instead of printing the entire solid. The On-the-Fly-Print system builds on that idea by allowing the designer to make refinements while printing is in progress. The new system has “five degrees of freedom.” The nozzle can only work vertically, but the printer’s stage can be rotated to present any face of the model facing up; so an airplane fuselage, for example, can be turned on its side to add a wing.