3D print what you are designing as you design it

3D printing is a powerful tool for engineers and designers, allowing them to do rapid prototyping by creating a physical copy of a proposed design.

This wire frame prototype of a toy aircraft was printed in just 10 minutes, including testing for correct fit, and modified during printing to create the cockpit. The file was updated in the process, and could be used to print a finished model.
CREDIT: Cornell University

One of the challenges is making changes to the design, forcing the entire print model to be discarded and reprinted. Cornell researchers have developed an interactive prototyping system that prints what you are designing as you design it. This system allows the designer to 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.

“We are going from human-computer interaction to human-machine interaction,” said graduate student Huaishu Peng, who described the On-the-Fly-Print system in a paper presented at the 2016 ACM Conference for Human Computer Interaction. Co-authors are François Guimbretière, associate professor of information science; Steve Marschner, professor of computer science; and doctoral student Rundong Wu.

Their system uses an improved version of an innovative “WirePrint” printer developed in a collaboration between Guimbretière’s lab and the Hasso Platner Institute in Potsdam, Germany.

The WirePrint technique uses a nozzle to extrude a rope of quick-hardening plastic to create a wire frame that represents the surface of the solid object described in a computer-aided design (CAD) file. 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.

This new system offers greater print freedom. The nozzle works vertically, but the printer’s stage can be rotated to present any face of the model facing up and includes a cutter to remove parts of the model. Extending the nozzle allows for more reach to make interior changes. The system also includes a removable base aligned by magnets allows the operator to take the model out of the printer to measure or test to see if it fits where it’s supposed to go, then replace it in the precise original location to resume printing.

The software designs the wire frame and sends instructions to the printer, allowing for interruptions. This allows the designer to concentrate on the digital model and let the software control the printer. Printing can continue while the designer works on the CAD file, but will resume when that work is done, incorporating the changes into the print.

By creating a “low-fidelity sketch” of what the finished product will look like and allowing the designer to redraw it as it develops, the researchers said, “We believe that this approach has the potential to improve the overall quality of the design process.”

www.cornell.edu