Orbex has introduced the world’s largest metal rocket engine 3D printed in a single piece, produced on an SLM800 system from SLM Solutions.

Founded in 2015, Orbex develops small satellite launch vehicles. The spaceflight company introduced Prime, its revolutionary, environmentally-friendly rocket at the grand opening of its new headquarters in Forres, Scotland. The novel Orbex launcher not only uses 100% renewable fuel to cut carbon emissions by 90%, and a novel zero-shock staging and payload separation resulting in zero orbital debris, but was also design-optimised for selective laser melting (SLM), helping to create a structure 30% lighter and 20% more efficient than any other launch vehicle in its category.

Orbex aerospace engineers partnered closely with the applications engineering team at SLM Solutions’s headquarters in Lübeck, Germany, to ensure success transferring the design into SLM production – a feat that required the partnership of the equipment provider due to the complexity and size of the component.

Applications specialist Lukas Pankiewicz headed the consulting team inside SLM Solutions to develop a unique set of parameters optimised for this particular geometry. Working closely with the design team at Orbex, Pankiewicz consulted on the various design features and orientation options, while ensuring the part was 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,” he explained. “Every single support structure used in data preparation has been customised to obtain the best quality in every section of the engine, taking post-processing into consideration as well.”

The SLM800 large-format metal additive manufacturing system features a 260mm x 500mm powder bed that can build parts 800mm tall, allowing the Prime engine to be built in a special nickel alloy in a single piece. The SLM HUB unpacking system for the SLM 800 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. Pankiewicz ensured a powder removal strategy was incorporated into the build with purpose-driven delivery channels to be certain as much powder was removed as possible while reducing material loss.

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 realise both time and cost reductions – saving 90% in turnaround time and over 50% in costs compared to traditional CNC machining production.

“This has always been what SLM Solutions is about,” said Dr Axel Schulz, Chief Sales Officer of SLM Solutions. “Members of our team helped invent selective laser melting technology! We’ve always wanted that technology to succeed – which isn’t just about selling SLM machines but creating that paradigm shift for the customer to be successful with their process. SLM Solutions consulted Orbex on how to make the technology best work for them and transferred that knowledge to ensure their successful implementation as they ramp up to production.”

Jonas Bjarnoe, Chief Technology Officer of Orbex, stated: “The SLM Solutions team showed true dedication and in-depth knowledge of our work. I’m looking forward to continuing this collaboration in 2019 and onwards. Orbex and SLM Solutions have solved some important puzzle pieces which will change the space business.”

Pankiewicz concluded: “I think it is a dream of every engineer to build a rocket and I feel honoured to be a part this project with SLM Solutions and Orbex.”