How big an aircraft engine could you make with 3D printing?  Would you believe a full-size engine with propeller blade-span over 10 feet?  That was the result when Autodesk and Stratasys pooled forces on a project to demonstrate how far 3D modeling has advanced.

The engine’s design was created using Autodesk Inventor 2010 mechanical design and engineering software, and it was produced on both Fortus 3D Production Systems and Dimension 3D Printers from Stratasys, using FDM (Fused Deposition Modeling®) technology.

“Our Inventor software with FDM technology takes design innovation to an entirely new level of sophistication,” says Autodesk’s Gonzalo Martinez, office of the CTO. “We’ve shown that with FDM, you can create realistic 3D models of nearly any design.”

The engine’s gearbox includes two sets of gears, which operate two sets of propellers that move in counter rotation to each other. With an engine length of over 10 feet, a blade-span of 10.5 feet, and 188 components, the engine model is massive in size. It includes several large parts, such as six propeller blades, each measuring 4.5 feet.

Building this physical model with FDM helped improve its design by identifying four opportunities to make components fit or operate with better precision. Assembling a physical model helps design engineers be certain of component form, fit, and function.

The turbo-prop engine was designed by Nino Caldarola, a freelance designer for Autodesk. He shared his concept with Autodesk who wanted to bring a full-scale model to life using Inventor software and FDM technology. Caldarola’s design is a hybrid of newer engine and classic engine design and was partially inspired by the Piaggio Avanti II aircraft engine, the TP 500.

Model engine’s gear box includes two sets of gears, operating separate sets of propellers with a blade-span of 10.5 feet.

All 188 components were produced in 4 weeks and assembled in 2.5 weeks for a total production time of 6.5 weeks. Contrast that with conventional fabrication processes, such as machining and casting (with in-house and outside resources); a manufacturer would expect to spend 9 months or more producing a model like this. Using the FDM process in-house, a manufacturer could expect costs of roughly $25,000, versus an estimated $800,000 to $1 million for conventional processes. These numbers represent about a 97% reduction in production costs and 83% reduction in production time.

“It was spectacular seeing my computer design brought to life with a 3D model,” says Caldarola. “I worked under a tight timeline and across geographies with both Stratasys and Autodesk, and I am very proud of the collaborative process and result. Just a few years ago, a project of this scale would have never been attempted.”

“This project shows that 3D printing has made the progression to large format,” says Stratasys CEO Scott Crump. “Hopefully this project will help make manufacturers aware that a designer can conceive and design a product this significant, and then have it physically modeled in about 6 weeks.”  After creating complex models with additive fabrication, manufacturers can then use the CAD files to create perfect-mating jigs and fixtures to support production processes.

Stratasys, Inc.
www.stratasys.com

Autodesk, Inc.
www.autodesk.com

MPF