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energy

Finally united: two giants for the future of wind energy

The second large machine is ready for use – a new production duo has been put into operation in perfect harmony at HACO A/S.

The Danish family-owned company is now equipped for the future of wind energy: It can now machine huge rotor housings and brake discs for offshore wind turbines in the 14 to 15 megawatt class even more efficiently and precisely.

The small town of Rødekro in southern Denmark, near the German- Danish border, is developing into a logistical hub for the offshore wind industry. The proximity to the port of Esbjerg, Northern Europe’s leading offshore wind hub, and to the ports of Aabenraa and Sønderborg, enables efficient transport routes for wind energy components. The close cooperation between HACO and SM Industrie A/S, a leading supplier of steel wind energy components, is a current example of sustainable logistics. The new machine duo will be used in a hall on SM Industrie’s premises.

Machine duo with standardised operation

A large Droop+Rein gantry machine with a travelling gantry, which can flexibly machine very large workpieces in a single clamping operation, has been in use since the beginning of 2024. It has recently been supported by another very large Dörries gantry machine with a fixed gantry and sliding base. Despite all the differences, both machines are based on the same core components, making maintenance and operation simpler.

The new large gantry machine significantly expands HACO’s machining range. Thanks to the improved main drive and the increased swing diameter of the workpiece, it is now possible to manufacture more substantial, welded rotor housings and other large components with precision. “Our two large machines – two true giants – are now in production,” says a delighted Hubert Erz, Senior Consultant Sales/Renewables at Starrag, who has been supporting the southern Danish contract manufacturer for more than a decade. “We are setting a new benchmark in the machining of workpieces for gearless wind turbines in the 14 and 15 megawatt power classes. The focus here is primarily on rotor housings, i.e. generator housings, and brake discs, both of which currently have a diameter of around 9,000 mm and are manufactured with an accuracy range of +/- 0.1 mm.

When the specifications call for high precision

This is where precision comes into play: The wind energy industry typically demands tight tolerances in its specifications for large components such as rotor housings and brake discs. “Regardless of the size of the machine, it is important to precisely calculate and dimension the main components using modern design tools,” explains Erz. “We achieve the first static compensation as early as the moulding stage.” In addition, there are precisely adjustable mechanical components and final electronic fine-tuning as well as a precisely designed machine foundation that takes static and dynamic loads into account. Precision stands and falls with automation and control. Yet HACO also prioritises production reliability and continuity. That’s why the family-run company deliberately decided against the latest Siemens control system. Instead, Managing Director Henning Albrechtsen favours the tried-and-tested version: “We rely on tried-and-tested technologies. This not only ensures production reliability, but also the flexibility of our employees.”

The Dörries large gantry machine has been in use since the end of 2024.

Better safe than sorry: simulation of complex machining processes

Instead, the managing director invested in programming and simulation. New post-processors with an integrated simulation module from the British Starrag subsidiary TTL enabled his team to create NC programmes in the main factory and simulate the machining process, including measuring programmes, in advance – an approach that significantly increases productive machine running time. In addition, the second machine was equipped with a modern magazine concept with automatic loading and unloading of tools as well as six machining heads for turning, milling and drilling, which enable flexible and precise machining of large parts in a single clamping operation. The two 870-tonne machines required a foundation that could cope with the enormous static and dynamic loads and thus ensure precise machining. Starrag took extensive assembly and handling precautions during the design phase to ensure the transport and precise alignment of these substantial components. A central element is the two-storey basement, which serves as a stable base and facilitates access to central components. HACO and Starrag also tackled this challenge together. The customer is satisfied: “We integrated units into the foundation, so that noise emissions were virtually eliminated – a clear plus point for the quality of work.”

A Droop+Rein gantry machine with a travelling gantry, which can flexibly machine very large workpieces in a single clamping operation, has been in use since the beginning of 2024.

Sustainable concepts for the wind energy industry

The new machine duo was created in Starrag’s LPMS (Large Parts Machining Systems) business unit – a unit that specialises in innovative manufacturing solutions for large parts and is guided by the strict criteria of the VDMA BLUECOMPETENCE label. This also had a lasting effect on this project. Modern, energy-optimised components, advanced drive technology and the recovery of surplus energy ensure reduced energy consumption at HACO’s plant in Rødekro. These measures lower material consumption, reduce waste and optimise energy use – a competitive advantage for industries that focus on sustainability.

Take two: machine duo sets the benchmark

The investment in two large machines offers excellent opportunities for the machining of current and future large components for the wind energy industry and other sectors. The deliberately chosen flexible design and equipment of both machines set virtually no limits for the machining of large components. Erz: “The courage of Henning Albrechtsen and his team is now paying off. Together, we have created a new plant that will enable our regular Danish customer to manufacture future, larger generations of wind turbine and XXL components sustainably, efficiently and reliably.”

Interview with Henning Albrechtsen, Managing Director of HACO, meets the high demands of the wind energy industry with three innovative strategies.

Into the future of wind energy with XXL efficiency

Mr Albrechtsen, why do you rely on the combination of milling and turning in one system?

Henning Albrechtsen: For years now, we have been practising complete machining – i.e. production in as few clamping operations as possible, including turning, drilling and milling – with our Dörries machines at our main site in Barrit. The experience we gained there flowed directly into the planning of our systems in Rødekro. The larger the workpieces, the more complex the handling becomes. Reason enough for us to develop a clamping device with which rotor housings, for example, can be finished in a single clamping operation.

With the basement and the new layout, you are breaking new ground in production. How does this structure affect ergonomics and ease of maintenance?

Henning Albrechtsen: There are two main objectives behind the joint, intensive planning and foundation work. On the one hand, to reduce noise emissions and, on the other, to optimise access to all machine assemblies. This enables fast maintenance and repair work and keeps machine availability at a high level – a decisive advantage when production pressure is high. We were also able to integrate units directly into the foundation, i.e. in the basement. This has further reduced noise emissions and noticeably improved the quality of our employees’ work.

The wind energy industry is increasingly focusing on new materials: How does HACO ensure that its production is also optimised for future materials?

Henning Albrechtsen: Our machined components – including rotor housings, brake discs and stator laminations – remain predominantly welded workpieces, even though they will be manufactured in larger dimensions in the future. At the same time, our product portfolio has expanded. In addition to traditional parts, we now also machine castings, such as generator housings and adapter components for connecting the nacelle and tower. This puts us in an ideal position to meet the requirements of the next generation of wind turbines.