A decade ago, engineers at GE Aviation made a breakthrough while designing a more fuel-efficient jet engine. The breakthrough was a new fuel injector nozzle that sprayed fuel into the engine’s combustor and allowed for better fuel and air mixing. The problem, however, was the geometric complexity of the nozzle’s interior. It was impossible to construct through traditional subtractive manufacturing, which required the welding and brazing of 20 parts into complex internal shapes. Rather than giving up on the idea, the engineers turned to additive manufacturing to solve their issue. Additive manufacturing, or 3D printing of parts from digital models, combined all 20 of the nozzle’s parts into a single unit. This process improvement not only made the construction feasible, it reduced the nozzle’s overall weight by 25% and improved its durability by five times.  The fuel injector nozzle, which was approved for flight by the Federal Aviation Administration in 2015, highlighted the ability of additive manufacturing to make complex parts economically.  Realizing its potential, GE quickly invested significant resources into additive manufacturing and began focusing on an even more ambitious project—the Advanced Turboprop engine (ATP).
Why is additive manufacturing important for GE’s ATP development?
What differentiates the ATP from the fuel injector nozzle is scale and complexity. The ATP, which will be used in the Cessna Denali single-engine turboprop aircraft, originally consisted of thousands of subtractive manufactured parts. Like the fuel injector nozzle, the engine has a complex geometric design which normally would use bolts and welds to fit each of the parts together. These joints are often the weakest points within a design. The revolutionary aspect of additive manufacturing is that it reduces the number of unique parts, thus limiting the number of joints. This fundamentally changes the creative design process for engineers. As Chris Schuppe, general manager of engineering for GE Additive, explains, “When we free an engineer’s mind from the constraints of how a part needs be designed so it can later be assembled, the engineer can activate the creative side of his or her brain to design parts that have never been built before.”  Within the ATP, GE engineers have reduced 855 subtractive parts into 12 additive parts. The additive parts account for 35% of the engine’s total architecture, reducing the weight by 5% and increasing specific fuel consumption, a measure of efficiency, by 1%.  In addition to the engine’s improved metrics, printing parts occurs more quickly than conventional assembly methods. In terms of the product development process, engineers can test hardware sooner and use the resultant test data for next iterations—additive manufacturing expedited initial testing for the ATP 6 months ahead of schedule. 
GE believes the additive manufacturing market could grow to $76 billion within a decade.  In order to capture market share early, the company invested over 1 billion dollars in 2016 to launch GE Additive, a network of manufacturers up and down the additive supply chain. Leveraging the learnings and success of the fuel injector nozzle and ATP, GE Additive looks to move from producer of additive parts to the leading supplier of additive machines and materials over the next 10 years. 
While GE’s advances in additive manufacturing are exciting, the days of 3D printers on every corner to print parts just in time for customers is still far off. In fact, additive manufacturing only makes sense for highly complex and customizable products, like jet engines, and almost all currently manufactured products are standardized.  If GE wants to make additive manufacturing feasible for local manufacturers, they need to focus on the economics of the additive decision. This not only includes offering machines at comparable prices to traditional manufacturing equipment, but also involves making the technical training for the setup, operation, and troubleshooting of printers more affordable to reduce labor costs. In addition, expertise currently does not transfer easily from one type of printing process to another (for example, plastic to metal manufacturing), so GE should develop machines with convenient, multiple-use printing capabilities. 
- In the future, how can additive manufacturing be used most effectively in product development? Should it be limited to prototype development and the production of complex parts? Is it too expensive and technical to be used for mass production of commercial products?
- Is GE making a smart investment in additive manufacturing? In what industries and use cases should they be focusing their efforts?
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