Back in September, 3DPrint.com reported that LEGO was preparing to release its first mass-produced 3D printed element inside an upcoming LEGO Christmas set. At the time, details were limited to a LinkedIn announcement from Ronen Hadar, Senior Director of Additive Design and Manufacturing at the LEGO Group, and a description of the miniature blue locomotive that would debut the company’s high-throughput polymer AM process.
Now the set, called Holiday Express Train from LEGO Icons, is officially available for purchase worldwide, and LEGO has published a look at the technology behind the tiny train, confirming both its importance and the long development timeline that made it possible.
According to the brand, the miniature locomotive included in the Holiday Express Train is the first 3D printed part ever sold at retail in a LEGO set. While the company has released a handful of AM-made elements in limited quantities over the past several years, including a drafting arm, duck, and pogo stick, this marks the first time a printed piece is being produced at scale and distributed through one of its standard commercial sets.
This 3D printed train piece is part of the LEGO Icons Holiday Express Train set.
The part itself is a micro-version of the set’s main train, complete with spinning wheels and a functional chimney. LEGO designers Bo Park Kristensen and Jae Won Lee collaborated with the additive manufacturing team to create a geometry that could not be achieved through injection molding. For LEGO, the point was not to replace molding but to open up entirely new forms and functions for future play features.
“October 2025 marks a milestone that has never been done before,” described Park Kristensen in a social media post. “I have been so fortunate to explore and develop a new brick in additive manufacturing for a retail product in mass production for The LEGO Group. We have for many years used 3D prints in our development phase, but it is the first time we use it on a full scale. Many things needed to be settled for this to come alive, but in the end, we succeeded from all ends to deliver this piece. This marks a new addition to our product offerings. Hope you enjoy.”
Park Kristensen also explains that the 3D printed element could have been many things, but in the end, the team decided that this train would be the first mass-produced 3D print in a LEGO box.
LEGO Icons Holiday Express Train set.
For the LEGO Icons Holiday Express Train set designer Won Lee, the 3D printed train was the perfect way to add an extra dimension to the new set, which was itself an update on the LEGO Creator Expert Winter Holiday Train set from 2016. Two child minifigures from that earlier set now feature in the Holiday Express as grown-ups delivering toys to a new generation of kids, and the design team, curious about the potential of 3D printing and eager to try it out, realized that these small toys could be an opportunity to create that first printed element, noted Won Lee.
LEGO engineer working on 3D printed parts.
LEGO also confirms several new details not previously disclosed. Hadar says the company spent nine years developing the AM platform in Billund, Denmark, building a system capable of producing high-quality parts at a rate suitable for consumer products. The team has already doubled the output speed of the machines and is targeting further improvements as more sets incorporate printed components.
LEGO Icons Holiday Express Train set.
While LEGO does not mention the specific machine configuration used to produce the element, the company previously referenced EOS technology in internal communications. What is clear is that LEGO considers this release a major milestone, with Hadar even comparing it to the company’s adoption of injection molding in the 1940s. He says his long-term goal is to make 3D printed elements “boringly normal,” a standard part of the LEGO design toolkit rather than a novelty.
Although for now, the Holiday Express Train is just a first real glimpse of that future Hadar describes so passionately, the printed micro-train represents a huge step in bringing industrial additive manufacturing directly into the hands of millions of LEGO fans. As more designers begin experimenting with the technology, LEGO hints that similar “dynamic elements” could appear in upcoming sets.
LEGO Icons Holiday Express Train set.
Images courtesy of LEGO
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