German vehicle manufacturer Daimler Buses has started three-dimensional (3D) printing of small batches of parts, as well as replacement parts for the Mercedes-Benz and Setra bus brands.

Daimler Buses says 3D component production is the ideal solution to enquiries, received on a daily basis, from customers seeking special equipment features, or replacement parts.

Some 780 components have been printed for customer vehicles to date.

In addition, more than 150 different replacement parts are being scrutinised and validated to determine their feasibility as 3D-printed parts.

“In the medium term, we see digital production technologies as harbouring vast potential to enable us to address market and customer requirements in a flexible manner, while at the same time minimising investment risks,” says Daimler Buses head Hartmut Schick.

The 3D printing process avoids the costs related to tool production, component storage, production bottlenecks, surplus production and the disposal of surplus materials.

Special parts and low-volume parts can also be modified at will and adapted to the special requirements of customers.

In most cases, 3D-printed parts also prove more favourable than their conventionally produced counterparts in terms of weight, as the design engineer is no longer restricted by the constraints previously imposed by the production process, which means he or she is able to adapt the components ideally to their given functions, for example.

The parts correspond to the injection moulding standards stipulated by parent company Daimler.

The printed special and replacement parts consist of high-quality polyamide plastic components.

They are created with 3D printers based on the selective laser sintering printing process. In this process the 3D structure of the preprogrammed 3D parts are produced layer by layer from the powder-form polyamide materials by means of a laser.

The 3D printing process has proved particularly economical in small series involving batch sizes from 1 to 50 units.

The entire process, from the initial idea through to design, costing, production and delivery, takes a matter of days.

One example of a special 3D printed part is the stowage compartment for banknotes which Mercedes-Benz integrates, on request, in the side panelling on the left-hand side of the driver’s area, in place of the cup holder.

This component comprises a number of individual parts: the housing, various assembly clips, hinges, lid, handle and compartments.

The conventional production process would entail manufacturing all of the individual parts using various thermoforming and injection moulding tools, followed by the joining of the parts. 3D printing, however, produces the compartment in a single step.

“The 3D printing process allows us to install local printers at the production plants operated by Daimler Buses worldwide. In this way, the availability of parts can be sped up considerably while avoiding long transport distances, as well as high transport costs and customs charges,” explains Schick.