On the left a conventional 3D printing machine, on the right the rotating machine from Rapture, in which the laser continuously melts the powder. © Michael Tucker / ETH Zurich

The students have now built what ETH Zurich reports to be the fastest multi-material metal printer: The new laser melting machine rotates powder and gas nozzles simultaneously during printing. This allows it to process several metals in a single pass without pauses. The machine could fundamentally change the 3D printing of metal parts by significantly reducing production time and costs.

Project Rapture: students develop the machine

The six-person team of Bachelor students in their fifth and sixth semesters developed the new machine as part of the Rapture focus project at the Laboratory for New Manufacturing Technologies under the direction of ETH professor Markus Bambach and scientist Michael Tucker. In just nine months, the students turned the idea into concrete plans, built and tested it.

3D printing in rotation

A completed guide ring for a high-pressure turbine with a diameter of 75 millimeters. © Michael Tucker / ETH Zurich

The core of the new machine is a rotating platform that enables a fast printing process. Unlike conventional rectangular laser melting systems, where a new layer of powder has to be applied after each fused layer, Rapture's machine works continuously thanks to the rotating platform: the machine can apply powder and have it fused by the laser at the same time. This significantly increases productivity. The production time for cylindrical components is reduced to less than a third.

Rocket nozzles, rotating engines and numerous aerospace components are ideal for this process, says Tucker. They typically have a large diameter but very thin walls. Although the machine can also produce non-axisymmetric parts or entire arrays of components, the rotating process is particularly efficient for ring-shaped geometries.

Two metals in one pass

The rotating machine can process two different metals simultaneously in a single pass. Conventional systems require several steps and significantly more metal powder. As mixed powder is difficult to separate and reuse, it is usually lost as waste. The new process only applies the material where it is actually needed on the component, thus saving material.

The machine blows a special gas over the area where the powder melts to stabilize the process. Nitrogen prevents the component from oxidizing during printing. Soot, spatter and other by-products are removed via a fume cupboard.

"We initially underestimated how much this gas flow device affects the quality of the product," says Tucker. "Today we know that it is crucial."

Thanks to the rotating architecture of the newly developed machine, the gas flows at the processing point can be controlled much more precisely than with conventional systems.

3D custom work instead of standard components

The students had to overcome several technical hurdles when developing the innovative laser melting machine. One of these was to precisely synchronize the laser beam with the rotation of the gas supply and the powder supply. Many of the components required for the machine were not commercially available, so the team designed them themselves. These included a rotating connection for the gas supply system and a system that automatically refills the powder during operation.

Despite this, the student team managed to build a machine that looks almost industrial-grade. For Tucker, this was one of the highlights of the focus project: "For a team of students to develop and build a functional machine in nine months is extraordinary."

Potential for space travel and e-mobility

In addition to specific applications for Aris and the aerospace industry in general, the team also sees potential applications in other areas, such as aircraft or gas turbines and electric motors, where ring-shaped geometries are typical.

Due to its novelty and great economic potential, ETH has applied for a patent for the rotating multi-metal laser melting technology. It has now also been nominated for the ETH Spark Award.

The components produced so far with the prototype have a diameter of up to 20 centimetres. The research team is now working on scaling up the process to higher speeds and larger diameters. To this end, the researchers are currently looking for industrial partners who would like to work with them to further develop and apply the technology.

Publication:
Bambach, M., & Tucker, M. R. (2025). Design and analyses of powder deposition, gas flow, and productivity for a rotary laser powder bed fusion system. CIRP Annals, 74(1), 315-319. DOI:10.1016/j.cirp.2025.04.005

Source: Swiss Federal Institute of Technology Zurich, Deborah Kyburz