LEGO Group, the Danish toy manufacturer known for its interlocking plastic bricks, has taken a decisive step in its production history. The Icons Holiday Express Train (10361) set includes the first 3D printed element ever to appear in a retail product. A miniature blue locomotive, designed as a replica of the main train, represents nearly a decade of work by the company’s Additive Design and Manufacturing team in Billund, Denmark. The set went on sale in October 2025.
Ronen Hadar, Head of Additive Design and Manufacturing, described the achievement as comparable to one of the company’s foundational milestones. “This feels like a move similar in magnitude to when our founders purchased their first injection moulding machine back in the late 1940s,” he said. Hadar and the Billund-based team have spent nine years developing an in-house 3D printing system capable of producing high-quality elements at industrial scale. Until recently, additive methods were used only for prototypes, with a single brick sometimes taking hours to complete. The new process enables production rates suitable for mass manufacturing while maintaining the dimensional accuracy that defines the brand’s construction system.
Injection moulding remains the backbone of production, refined over decades to ensure consistency and throughput. Hadar emphasized that 3D printing is not intended to replace this process but to expand design possibilities. “We can make all kinds of geometries that are not possible with injection moulding—bricks with internal mechanisms, for example,” he explained. The miniature train demonstrates those capabilities through spinning wheels and a puffing chimney—features difficult to achieve with conventional tooling.
Bo Park Kristensen, the designer behind the smaller train, said the element’s selection was intentional. “It could have been many things,” he noted. “But in the end, we decided that this train would be the first mass-produced 3D print in a LEGO box.” Jae Won Lee, designer of the main Holiday Express Train, saw the printed miniature as a way to connect the new set to the Creator Expert Winter Holiday Train (10254) released in 2016. Two minifigures from that earlier edition reappear as adults delivering toys, linking past and present within the company’s holiday collection. The design team identified the miniature as an ideal candidate for debuting the first printed element while maintaining continuity with earlier sets.
Engineers in Billund had to develop much of the production process from scratch to reach this point. Rapid industrial-scale additive manufacturing was not established when the project began, requiring new methods to control material behavior, color matching, and surface finish. Collaboration between additive specialists and product designers proved critical, Hadar recalled. “We’re additive manufacturing experts, but they’re designers,” he said. “They have that creative power to really apply the technology outside of what we thought was possible.”
Efforts now focus on refining throughput and reliability. Hadar said his department has already doubled the output rate of its printing machines and continues to push for further efficiency. The long-term objective is to make 3D printed parts a standard option for designers, indistinguishable in quality from injection-moulded bricks. “We still need to learn more about how to apply the technology, and where to apply it,” he said. “My task is to make 3D printed elements boring—so people don’t think about how they were manufactured; they just think it’s a cool element that gives them something fun to play with.”
The miniature locomotive in the Holiday Express Train may appear small, yet it signals a significant transformation within one of the world’s most recognizable toy companies. Additive manufacturing is moving from experimental prototypes to functional production components, marking the start of a new chapter in how future generations of bricks will be made.
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Featured photo shows LEGO Icons Holiday Express Train (10361) set featuring the first 3D printed element ever released in a retail LEGO product. Photo via LEGO Group.
