Advanced industries require the development of special tooling, but some of these tools cannot be made using traditional manufacturing and machining technologies. These tools need to be engineered and developed from scratch and 3D printing helps bring them to life. Any-Shape is an expert in the creation of specific tools for the high tech industry with additive manufacturing (AM). Through its engineering department and AM production capacities, the company helped improve an aluminum tool for aerospace. Previous versions of the aluminum tool incorporated less complex embossing of the inner surface. As a result, machining was used as default process. For this new tool design requirements implied a much more complex inner surface with areas that are impossible to machine. Thus, it was decided to manufacture the tool using AM on an EOS M 290 combined with some post-machining. By EOS.
The project started when Any-Shape received a request for an aluminum tool with a very complex embossing of the inner surface. These tools are usually machined, but this design made that impossible as some zones of the inner surface just could not be reached and could therefore not be machined.
In addition, the technical requirements for the tool mandated extremely high precision combined with a very low tolerance as it was destined to be a precision tool:
- Surface roughness of the nonmachinable inner surface of 3.7 +/- 0.5 μm Ra
- High dimensional accuracy on the final assembly (0.05 mm on control points position, +/- 0.1 mm inner surface tolerance)
Two additional challenges were also on the table:
- The tool had to be as lightweight as possible for a more convenient handling by the operators during the final usage
- The integration of a part that had to be assembled by hybrid joining after additive manufacturing due to build size limitation of the EOS M 290
The expertise in additive manufacturing of Any-Shape helped fulfill all these requirements. The company has a very deep knowledge of design for AM and post process machining, enabling them to easily translate the requirements into production features. Using their EOS M 290 machine and unique EOS Aluminium AlSi10Mg material and process, Any-Shape had all the skills to meet the design and technical requirements for this complex tool as well as the production and post-treatment capacities to deliver the project on time.
A complete aAM strategy was set up to answer all challenges at once, both technical and ergonomic. Any-Shape had to take into account all the parameters for the AM itself but also the assembly operations that had to happen afterwards.
One of the first actions undertaken was to position the inner surface at the correct angle to optimise surface roughness. This position constraint then defined how the part support had to be placed underneath.
Shrinkage lines also had to be monitored very closely, especially because of the aforementioned position constraint. The design of the zones close to the articulation was slightly modified to allow for smoother exposed area transition, completely eliminating the shrinkage lines.
Another impact of the position constraints was the obligation to define how the cut had to be made on the largest component that had to be reassembled after manufacturing. Therefore the cut was designed specifically to:
- Leave one translational degree of freedom to enable assembly, as this assembly had to really fit due to the stringent tolerance on the surface accuracy
- Maximise the shear loading mode in the adhesive bond line area
- Ensure a 0.2 mm bond line thickness thanks to spacers integrated into the manufacturing design
Finally, additional features were designed to be used for referencing positions and clamping during post manufacturing machining.
Thanks to the 3D printing expertise of Any-Shape and its manufacturing strategy, the different parts were successfully printed, post-machined, re-assembled and successfully passed quality control.
The main part went through sandblasting for surface treatment, offering an average roughness of the inner surface after processing of 4μm Ra that complied with customer requirements based on previous tests.
Quality controls were made based on the initial design of the parts. Tolerances were met for all references. The surface accuracy after post-treatment was well within +/- 0.1 mm on each of the articulated arms inner surface taken separately, and +/- 0.2 mm on the final tool.
Finally, on the full assembly, no deviation jump could be observed either at the locus of the articulation or at the cut and re-assembled interface.
Leveraging the capabilities of 3D printing, Any-Shape was able to create a unique tool by going beyond the limits of traditional manufacturing and machining. The team could manage a very complex project in a very short time thanks to the skills of Any-Shape and the capabilities of EOS.
Regarding this achievement, Frédéric Lani, CTO of Any-Shape has commented, “It was a very challenging and complex project from beginning to end. Thanks to our 3D printing expertise, we were able to develop an end-to-end manufacturing strategy, from re-design for AM to final quality controls using additive manufacturing and post-machining. All along this project, we had full support from EOS and their reliability, quality and support.”