According to a study by the Finnish research centre VTT, 5% of spare parts can be digitised and 3D printed. It’s a godsend for vehicle manufacturers, which are therefore able to manufacture on demand and reduce stocks. This is the very idea behind a project conducted by Siemens Mobility, which recently opened its first digital railway maintenance centre.
Saving time and reducing costs
The RRX Rail Service Centre of Siemens Mobility is located in Dortmund-Eving, Germany. There you can see a Fortus 450mc 3D printer by Stratasys manufacturing spare parts and bespoke tooling. Previously the group used classic subtractive manufacturing methods, such as injection moulding. Thanks to additive manufacturing, however, it has managed to reduce production time by 95% for certain parts. A 6-week production cycle can now take as little as 13 hours.
In addition to the reduced production time, Siemens Mobility is able to benefit from significantly reduced storage costs. The rail transport specialist will now produce its spare parts in accordance with need. It will no longer hold any physical stock, just a database of 3D files. Michal Kuczmik, Additive Manufacturing Manager at Siemens Mobility, explains:
“All trains are maintained several times a year. As you can imagine, all our customers would like the process to be as quick as possible, but they still expect our work to include attention to detail and maximum safety and quality. We also have to take unplanned and last-minute work into account, and given the different train models and companies we serve, this means numerous personalised solutions. This is where our Fortus 450mc is perfectly suited, enabling us to produce unique and personalised parts quickly and at lower cost.”
This level of efficiency is not insignificant. The railway maintenance centre takes in around a hundred trains each month.
3D printed tooling
Siemens also uses 3D printing for complex tooling applications. Let us take the example of the essential connector tool used in train bogie maintenance (the bogie is the chassis or structure that bears the wheelset axle). It is quite difficult to produce using conventional methods. It has a highly complex shape that requires a high degree of personalisation. Furthermore, bogies weigh several tonnes and robust and durable materials are required to stand up to the significant stresses exerted when the vehicle moves. But by using an industrial grade ULTEM 9085 thermoplastic material, Siemens is able to print complex tools adapted to each individual bogie.