In‑House Production: The Fuse 1 Builds Its Own Parts

The Fuse 1 prints end‑use parts directly.

An IR sensor purge, fabricated in Nylon 12 powder, was produced on the Fuse 1.

Building the Fuse 1 was an engineering feat. Delivering industrial‑grade performance in an affordable, sleek desktop selective laser sintering (SLS) printer required years of meticulous design and engineering.

Formlabs engineers used the Fuse 1 itself as a prototyping tool. Today, every unit shipped to customers includes multiple production parts printed on the machine using Nylon 12 powder.

According to Seth Berg, engineer program manager for the Fuse 1, using the SLS printer to prototype and produce end‑use parts offered three key advantages:

• The freedom to create complex geometries without internal support structures.
• Shortened supply chains by handling prototyping and production in‑house.
• Elimination of outsourcing, enabling affordable small‑batch production with the versatile Nylon 12 material.

SLS Prototyping and In‑House Production: Fabricating an IR Sensor Purge

Seth Berg discusses printing end‑use parts on the Fuse 1.

When customers install a new Fuse 1 and the Fuse Sift post‑processing unit, they may not realize that five distinct parts were printed on the printer itself. Among these, the IR sensor purge exemplifies a component ideally suited for small‑batch production with in‑house SLS printing.

One of the biggest challenges in developing the Fuse 1 was accurately measuring and balancing the internal temperature of the build chamber. Berg explained that the team needed a custom IR sensor purge to regulate heat within the print bay. Because temperature control was so sensitive, dozens of prototypes were expected before finding the optimal purge design. Outsourcing or injection molding would have been impractical due to the required iterations, so the team turned to their beta Fuse 1 units, powered by Nylon 12 powder, for both prototyping and production. “We needed a 3D printing technology that didn’t constrain geometry or add unwanted support tips to smooth airflow surfaces, so SLS was the only viable option,” Berg said.

Using early production units, the team designed, tested, and ultimately manufactured custom parts at scale, enabling the Fuse 1’s timely launch. Over time, more parts—door handles, IR handles, and Fuse Sift handles—were produced in‑house on beta units. Today, every shipped Fuse 1 contains multiple production parts printed directly on a Fuse 1. “We rigorously tested these parts, operating nearly 50 printers at headquarters nonstop to produce thousands of hours of print time,” Berg noted.

After refining dozens of prototypes, the team finalized the IR sensor purge design and transitioned seamlessly from prototyping to small‑batch production on the same printers. Thousands of parts are printed each week, validating the machine’s readiness for market. “At Formlabs, we prioritize product accessibility—both in price and maintenance. Seeing the Fuse 1 function as both a prototyping powerhouse and a full‑time production machine is highly gratifying,” Berg added.

Thanks to the Fuse 1’s dense build volume, a single print cycle can produce 12 IR sensor purges. For smaller parts such as the IR sensor handle, that number increases to 60 per cycle. While in‑house 3D printing is not yet cost‑effective for mass production of millions of parts, running multiple machines in tandem offers an excellent solution for small and medium batch sizes. The IR sensor handle consumes 22 g of powder, costing $2 per part; the main IR sensor purge uses 70 g, costing approximately $7 per part.

“Having the Fuse 1 in‑house absolutely resulted in an IR sensor purge that worked more effectively because we could iterate quickly and test numerous designs. We then moved directly to production using the same material,” Berg said. This eliminated the need to adjust tolerances between prototyping and production.

Seth Berg

Having the Fuse 1 in‑house absolutely resulted in an IR sensor purge that worked more effectively because we could iterate quickly and test numerous designs. We then moved directly to production using the same material.

Without the Fuse 1, Berg noted, the team would have been forced to outsource SLS services. “If we hadn’t had the Fuse 1 in‑house, we would have outsourced SLS parts to a service bureau, paying more and taking longer to obtain them. The Fuse 1 prints industry‑quality end‑use SLS parts in‑house at a fraction of the price and time,” he said.

Berg is confident that these parts perform reliably in their application, as every Fuse 1 shipped includes parts printed on the machine. The IR sensor purge, IR handle, door handle, and interlock magnet cover were all made possible by the Fuse 1.

Nylon 12 Powder for End‑Use Parts

The first material Formlabs launched for the Fuse 1 is Nylon 12 powder—a highly capable material for functional prototyping and end‑use production of complex assemblies with high environmental stability.

While other 3D printing processes can produce end‑use parts, SLS offers distinct advantages. SLS parts tend to last longer, especially under daily handling or use. Compared to stereolithography materials, Nylon 12 prints exhibit longer lifetimes, low creep, and superior wear, chemical, and UV resistance. “Almost all end‑use parts need to be tough and resistant to temperature and impact. Nylon strikes the sweet spot across these material properties. If you can think of an application where a part will be used, nylon is almost always the right choice,” Berg explained.

One notable feature of SLS powder printing is the ability to produce parts without internal support structures. Other processes require supports for internal crevices and openings, adding design constraints and post‑production time. SLS eliminates this issue, enabling complex parts with reduced post‑production effort.

Finally, Nylon 12 allows the Fuse 1 to print with up to 70 % recycled powder, a significant advantage for both prototyping and production. Berg’s team identified this as a core reason the Fuse 1 is a competitive production option: “All parts printed and installed on the Fuse 1 use 70 % reused powder. That’s one of the secrets that make in‑house manufacturing cost‑competitive.” He added, “We didn’t use recycled powder only for prototypes. On the production line, every part is printed with 70 % recycled powder, delivering end‑use parts that are both sustainable and economical.”

Learn More

Nylon 12 Powder

Nylon 12 powder is a highly capable material for both functional prototyping and end‑use production of complex assemblies and durable parts with high environmental stability. We put together a post covering your most frequently asked questions.

Learn More About Nylon 12 Powder

The Fuse 1: Now Shipping

Formlabs designs additive workflows that make industrial‑quality 3D printing accessible to businesses of all sizes. The Fuse 1 and Fuse Sift empower teams to control design, print production‑ready nylon parts in‑house, increase throughput, and bring industrial‑level SLS 3D printing to the benchtop at an entry‑level price point. All these elements—versatility of Nylon 12 and the unique benefits of SLS—helped Berg and the engineering team create a better Fuse 1.

Want to see how a part printed on the Fuse 1 looks? Request a free sample part now.