Orbex Rocket Includes Largest 3D Printed Part to Be Made in One Piece

Orbex, a U.K.-based spaceflight company, has introduced what is being called the world’s largest metal rocket engine to be 3D printed in a single piece using the SLM Solutions SLM800.

Orbex develops small satellite launch vehicles, and the 3D printed engine part was produced specifically for Prime, a supposedly environmentally-friendly rocket. The launcher uses only 100-percent renewable fuel to cut carbon emissions by 90 percent. A zero-shock staging and payload separation eliminates orbital debris. The launcher was design-optimized for selective laser melting, an additive manufacturing (AM) process, producing a structure 30 percent lighter and 20 percent more efficient than other launch vehicles in its category. Orbex aerospace engineers partnered closely with the applications engineering team at SLM Solutions headquarters in Lübeck, Germany, to ensure success transferring the design into selective laser melting production—a feat that required the partnership of the equipment provider due to the complexity and size of the component.

Lukas Pankiewicz, applications specialist, headed the consulting team within SLM Solutions to develop a set of parameters optimized for the engine’s particular geometry. Working closely with the design team at Orbex, he consulted on the various design features and orientation options, while ensuring the part built successfully with the required material properties and dimensional accuracy.  “Our aim during the process was to fulfill the quality expectations of the Orbex team, keep the functionality of the part and make it suitable for additive manufacturing. Every single support structure used in data preparation has been customized to obtain the best quality in every section of the engine, taking postprocessing into consideration as well.”

The SLM800 large-format metal AM system features a 260 × 500-mm powder bed that can build parts 800 mm tall, allowing the Prime engine to be built in a special nickel alloy in a single piece. The SLMHUB unpacking system for the SLM800 integrates contactless powder handling and automated build chamber conveyors to transfer the finished part to an unpacking station designed to remove powder through vibration and rotation. Mr. Pankiewicz made sure that a powder removal strategy was incorporated into the build with purpose-driven delivery channels. After production, reference samples built together with the engine were analyzed in the SLM Solutions’ metallography lab, where porosity level and distribution were proven to meet the quality acceptance criteria. The rapid iteration times inherent to the SLM process allowed Orbex to realize both time and cost reductions, reportedly saving 90 percent in turnaround time and over 50 percent in costs compared to traditional CNC machining production.