NEHER GROUP, a large German manufacturer of metal gearbox and steering casings, motor blocks and cylinder heads (as well as PCD and CVD tools, clamping fixtures, conveyors, lifters and leak test systems for the parts machined), reported that numerous of these tools have been manufactured by AM since the acquisition of a new 3D printer with a larger installation volume.
Because of the large bore diameters in stator housings of electric motors, ever-larger tools are required. Machining with a different type of tool would not be economical. The difficulty with this is that the current machine concepts cannot support the weight of such a large tool. So far, these tools have been designed as welded constructions, which, however, are very complex and therefore cost-intensive. This is one of the reasons why the NEHER GROUP has opted for a 3D printer that can achieve significant weight savings and clearly lower costs.
Several individual tools have already been manufactured since January 2020 and are currently being used by customers with process reliability. A very complex, multi-part, modular tool is currently in the testing phase.
The NEHER GROUP sees another advantage of AM in the arrangement and design of the cooling channels. Trials have already been started with customers with shell-type milling cutters in the 50 – 125 mm diameter range. In comparison to previous alternatives, significant improvements in the service life of up to 50% were achieved. The company is also moving in the direction of bionics. Based on the structure of a particular plant, a lathe chisel was designed that improves the damping properties of the tool. Such structures can only be designed generatively and produced additively, as conventional production reaches its limits.
The NEHER GROUP also sees additive manufacturing as a great opportunity to reduce CO2 emissions both in-house and with customers. Compared to a conventional system, the system requires less energy to create the same tool. By reducing the weight and, as a result, the mass moment of inertia, energy savings are also achieved for the customer.
In view of the change in the automotive industry, new types of components are of course also being manufactured. These are, for example, frame structure parts that are quite demanding in terms of manufacture and handling. Due to the thin-walled construction of the components, the challenge is to design the tools that minimize the milling noise through the arrangement of the cutting edges.
Another point is the development of chips, which is also of enormous importance here. The aim is to shape the chips in such a way that they are transported away by means of the cooling emulsion in the machine, thus ensuring trouble-free production. Furthermore, bores should be made absolutely burr-free, this requires know-how which the NEHER GROUP has developed over the years.