Lumenium (Rapid Prototyping) | Case Study

Introduction

Lumenium is a Virginia-based startup company from America that develops a range of innovative combustion engines. Known for the production of powerful and efficient internal combustion, Lumenium’s Inverse Displacement Asymmetrical Rotational (IDAR) engine is a novel and totally singular design that enables dramatic yet efficient output.

Sub-assembly of the Lumenium IDAR
Sub-assembly of the IDAR

Challenges

Lumenium’s IDAR engine technology is the fourth and new category added to the $350 million internal combustion engines market. These engines are subjected to substantial heat and stress during operations, so they must withstand dynamic loading conditions, combustion forces of 1500psi, and combustion temperatures of 1500 °C.

With strict performance requirements for such a complex product, multiple generations of engine designs with long phases of designing, prototyping, and iterating are inevitable.

Machining complex geometries with CNC of the majority of parts usually involves many complicated tool paths, and sometimes more than 80 different machining operations. A trained, dedicated operator is usually required for programming the CNC machine, and the process could take weeks for a single, more complex job – from design to creating the CNC tool path to fixturing to machining.

An additional time of three weeks is required for parts that require post-processing by outside vendors. The remaining parts, typically conventional, round parts – are sent to an outside machine shop where the average lead time is three weeks.

Assembled saddle and swing arm next to an installed swing arm within the Lumenium IDAR test engine
Assembled saddle and swing arm next to an installed swing arm within the IDAR test engine

The long lead time thus limits Lumenium’s ability to iterate on the design and improve engine performance, so a faster and more cost-effective approach to prototyping was critical.

Part weight too is an important factor, as it not only has a direct impact on engine performance but is also crucial to maintaining the overall power density and efficiency of the engine. With traditional manufacturing, there’s little to do beyond just selecting a lightweight material.

Earlier versions of the engine used parts machined from solid blocks of aluminum, a lightweight alloy. However, as aluminum expands as temperatures increase, it was an unfavorable property as a material for engine components that operates at high temperatures. Steel meanwhile has a coefficient of thermal expansion that is 68% less than aluminum.

Solution

Three parts – saddle carrier, swing arm, and connecting rod were submitted by Lumenium for initial benchmarking. These parts fit together in a sub-assembly of the IDAR engine, with design modifications made to adapt them for 3D printing on the Studio System.

Drilling and threading holes of Lumenium saddle
Drilling and threading holes of saddle

Through the implementation of 3D printing with the Studio System, printed parts comes with closed-cell infill – an internal lattice structure printed throughout the part. Strength and weight values can be adjusted with infill spacing to meet specific requirements, while infill printed parts also have significantly lower thermal transfer. This allows Lumenium to continue using steel as the material choice while reducing part weight and maintaining strength.

Results

For startups like Lumenium, functional rapid prototyping is particularly essential. With the implementation of 3D printing, Lumenium was able to quickly iterate on part features that can adhere to specific requirements, tackle complex part geometries, and enable a cost-effective approach to prototyping parts within the engine assembly.

Lumenium Case Study Comparison

Instead of the usual 3 to 5 years of product development by traditional manufacturing, the use of the Studio System reduced the one-year concept phase by 25%, the one-year design phase by 33% and one-year fabrication/iteration phase by 50%. This approach sees the overall product development timeline significantly reduced by 25%.

The ability to quickly iterate on part features and designs is critical for time to market and engine performance. With the Desktop Metal Studio System, they can bring affordable metal 3D printing in-house, and realize faster design iteration and functional prototyping.

Visit our Marketing Collaboration page to learn more about enjoying unparalleled innovation and design freedom with 3D printing implementation for your business.