Vertical turning lathe in practical use: Premiere of the new Dörries VT series

Virtual in Hanover, live action in Bielefeld

Production specialists will not only be able to experience the new vertical turning lathe virtually at the EMO 2025 trade fair stand: For the first time, they will also have the opportunity to see two machines in action under real-life production conditions at the nearby Starrag plant in Bielefeld – with a demonstration of large and complex components being machined.

Visitors are spoiled for choice in Hanover:
Should they experience the new vertical turning lathe digitally to save time – on a VR headset or on a large screen? Or take up the offer of a quick trip to the nearby Starrag plant in Bielefeld, which is less than an hour’s drive away?

Taking the machine for a spin in Bielefeld …

Heiko Quack, Sales Manager of the Large Parts Machining Systems (LPMS) division, recommends the somewhat more time-consuming option to all industry specialists who are faced with challenging decisions relating to their machining needs for large and complex components. For example, when they are considering the most productive way to manufacture planet carriers, engine housings or rotationally symmetrical structural parts with strict requirements for dimensional accuracy and surface quality.

“You can only see how a machine actually works under real-life conditions – how precisely the axes move, how smoothly a cut is made, how cleanly and quickly a tool change is carried out,” emphasises Heiko Quack. “Anyone who wants to machine these kinds of components in a cost-efficient manner should experience the Dörries VT 28 live in action – not just on a screen.” Two machines from the new Dörries VT series will be ready for action in Bielefeld, around an hour’s drive away.

In focus: Pre-machining and finish-machining of components

The new Dörries VT series from Starrag has been specifically designed for the sophisticated machining of large workpieces. The core of the machine is a water-cooled direct drive in the table, which is designed for a constant torque of 11,000 Nm at up to 85 rpm and a peak power output of 98 kW. It is designed without gear steps to reduce friction losses, enable highly dynamic positioning and lower maintenance costs. The drive unit is thus fully equipped to perform high-powered, continuous machining processes – even in three-shift operation (24/7) under industrial conditions.

These requirements can only be met by machine concepts that are designed for maximum performance in all areas: This applies not only to the drive, but also to all load-bearing and moving assemblies – from the guide geometry to the machine table. A key feature of the Dörries VT 28 is the use of Ultra High Performance Concrete (UHPC) in the table base. This replaces the classic cast part and ensures a high damping effect and thermal stability – an advantage under changing ambient temperatures and high machining volumes.

For the linear axes, Starrag continues to rely on tried-and-tested wear-free, hydrostatic guides with progressive flow control. These ensure constant rigidity over the entire travel path and minimize thermal influences during operation. The closed ram with extended cross-section (310 mm × 310 mm) also contributes to the overall rigidity of the machine structure.

Greater productivity due to handling during the machining time

In addition to the basic mechanical structure, the handling during the machining process is also designed for efficiency across the board. A robot-based tool handling system with up to 108 spaces allows rotary holders, milling heads and special units to be changed on an automated basis. The masterhead concept allows the flexible use of different attachment units – for example for angle machining, deep drilling or Y-axis machining. Loading and unloading processes run during the machining time to avoid any unnecessary downtime.

The modular architecture of the Dörries VT 28 further enhances the concept, as it permits more flexible application. The modular design makes it easier to adapt the machine configurations specifically to the respective application – be it for structural mechanical components for aviation, rotationally symmetrical workpieces for the energy sector or complex components for wind turbine gearboxes.

The concept has already been well received in India: The company Thaai Casting from Sriperumbudur near Chennai uses a Dörries VT 28 in a newly built, air-conditioned plant. The machine is specially configured for machining planet carriers for wind turbine gearboxes. Machining takes place with just two clamping operations – with automated tool changes, high dimensional accuracy and reproducible quality in continuous operation.

Two machines live in action: At the nearby Starrag plant in Bielefeld, trade visitors to the EMO 2025 (September 22-26) will experience two machines of the new Dörries VT 28 type under real-life production conditions – turning and cutting complex large components.