Foundry Corporate News Topic Patternmaking, mouldmaking and tooling & Rapid Prototyping, rapid tooling Topic Hand-mould casting

voxeljet: Imperia GP Roadster – History reinterpreted

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There will be a little bit of voxeljet technology in every Imperia GT retro-roadster. Using trend-setting hybrid technology, this Belgian eco-sports car combines pure driving fun with a clear conscience.

A hybrid engine with 350 HP and outstanding torque helps the Imperia ( achieve the driving values of a super sports car. It only takes four seconds to accelerate from 0 to 100 km/h. And that's only the beginning: The roadster also boasts sensationally low levels of CO2 emissions at 50 grams per kilometre.

The firm behind this technical innovation is Lüttich-based Green Propulsion, which has already brought several hybrid vehicle concepts to series readiness. For marketing the new roadster, the three company founders Yves Toussaint, Nicolas Naniot and Bernard Loly resurrected the Belgian automobile brand Imperia, which produced a vehicle with a fuel-electric motor as early as 1907.

Resurrection of a legend

The Imperia GP Roadster is the resurrection of a legend with entirely new technology. It derives its power from a 1.6 litre turbo gasoline engine with 200 HP, and an electric motor with an output of 150 HP. It also features an in-house developed gear unit with 4x2 gears. The production of the gear unit required some creativity, given the lack of large-series products available from suppliers' shelves.

But anyone developing innovative vehicles also knows a few innovative development partners. Hence the Imperia developers turned to French foundry Sicta, which specialises in the production of aluminium die casting prototypes. It looked to 3D printing as the solution for manufacturing the required sand moulds. After the initial discussions with voxeljet's service centre, everyone agreed: The Augsburg 3D experts would be the right partner for this ambitious project.

voxeljet Services is one of Europe's largest service providers for the on-demand production of plastic models and sand moulds for metal casting. More than ten 3D high-performance printers, including large format printers, which can generate moulds the size of a sports car, guarantee the rapid and efficient implementation of customer orders. A monthly print capacity of over 200,000 litres ensures short lead times even during times of high demand.

voxeljet is among the pioneers of the 3D printing field, and also offers a lot of experience and know-how. "The 3D printing of sand moulds for a prototype gear unit is one of those classic voxeljet tasks. These projects are always about producing small batch sizes quickly, efficiently and at a high quality. That is precisely the type of product for which our technology is considered the first choice," says voxeljet CEO Dr. Ingo Ederer.

Rapid and efficient: 3D printing of sand moulds

In contrast to the conventional manufacture of moulds, in which the production of model plates or core boxes alone can take several weeks, the sand moulds for the gearbox were printed on voxeljet's VX1000 high-performance printer in just a few days. The moulds are created without cumbersome and expensive mould set-ups, and are produced in a fully automated process purely based on CAD data using the layer building method, which consists of the repeated application of 300 micrometer thick quartz sand layers that are selectively glued together with a binder using the print head of the system.

The voxeljet print technology offers another advantage by using fine quartz sand. Compared to hand-made sand moulds, these finished cast parts feature a significantly smoother surface and impress with perfect quality. "The past few years have seen veritable quantum leaps with respect to printing quality as well as printing speed. The high-performance print heads of the new machines achieve excellent resolutions and printing speeds that are five times higher than even just a few years ago," says Dr. Ederer.

In addition to time aspects, there are also cost savings considerations that favour the use of layer building technologies. When examined with respect to total costs, up to a certain batch size 3D printing is significantly cheaper than conventional methods due to the lack of tool costs. The smaller the batch size, the greater the cost advantage offered by voxeljet's technology.

Imperia and the Sicta foundry were very impressed with the performance of the voxeljet service centre and the printed sand moulds. In addition to the cost advantages, the time aspect was also considered a very important factor. In this context, Sicta was able to deliver a gearbox of perfect quality to the Imperia team just three weeks after receiving the order. This is a big step towards bringing the legend back to life.


Aluminium casting

Imperia GP Roadster