Fused Deposition Modeling (FDM), which was invented in 1989, is probably what you imagine when you think of 3D printing. Traditionally, the technology melts spool-fed tubes of thermoplastic material and extrude the molten plastics in thin layers on a heated build-plate, building new parts from scratch slowly upwards, layer by careful layer. “It is the technique used by about 90% of the 3D printers in use today,” writes New Equipment Digest (Sept. 12, 2016).
The system—while simple and stable enough to build impressive objects and tools—has always presented a few fundamental limitations. First, FDM machines deposit materials in a closed, heated oven to help each layer properly melt and adhere. This presents an obvious limitation to the size of objects that can be printed—if you want to print a car in one pass, for instance, you would need a printer the size of a car. And then, there’s speed. If you have ever watched a 3D printer run, you know how maddeningly slow it can seem. Finally, the functionality of FDM parts is limited by the single-material nature of FDM.
So Stratasys, the 30-year giant in 3D printing, looked for a new system that could overcome the major roadblocks to FDM. They wanted a printer that could print larger parts in multiple materials consistently and accurately, faster than ever before. Conceived specifically for the aerospace and automotive industries, the Infinite-Build System fundamentally alters the basic “rules” for FDM printing, starting with those space-limiting ovens. The inspiration: just tip the whole system over and open the oven doors. Build the whole thing out instead of up. The new Stratasys system can print objects of any length, as long as the X and Y axes fit into the 4 by 2.5 ft chamber. The Z axis of the part just slides right out the back door as far as it needs to go. This means the system is capable of printing anything from customized car arm rest to an entire aircraft interior panel in one job.
Classroom discussion questions:
- How does additive manufacturing (3D printing) differ from more traditional machining?
- Why is this new system such an important OM tool?