Once again, the wheels are turning

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Once again, the wheels are turning ...

Introduction to the new Dörries VT 28 vertical turning lathe

Many industries value these machines because they have been running smoothly for over 20 years: We are talking about the Dörries Contumat VCE vertical turning lathes, which have proven themselves, for example, in the high-precision complete machining of components in many industries. The VT series is now set to continue this tradition.

Many industries value these machines because they have been running smoothly for over 20 years: We are talking about the Dörries Contumat VCE vertical turning lathes, which have proven themselves, for example, in the high-precision complete machining of components in many industries. The VT series is now set to continue this tradition.

Heiko Quack:
It’s a very robust machine with a stable design and generously dimensioned structural components for heavy and ultra-heavy machining, which is very durable and reliable. Many of our customers have been using the machine for many decades and are still using it today. Added to this is the hydrostatic guide concept with its outstanding damping properties. We’ll be retaining these features.

As a machine manufacturer, Starrag is characterised by its resilience. What were the reasons for introducing a successor to such a successful product as the Dörries VCE?

Quack: The last redesign of this successful series took place in 2009. So we need to develop a new generation that’s state of the art and retains the advantages of the VCE. We’ve analysed the market requirements and know that a new generation of turning lathes is needed. We’re moving away from heavy-duty machining towards multifunctional, high-precision and flexible pre-machining and finish machining. This requires less power and torque, as well as flexible interchangeable systems.

How has the newcomer affected the strategy?

Quack: Our strategy’s changed. After intensively analysing our products’ life cycles, we’ve decided where upgrades and new developments are necessary. We received help from other business units that think in terms of larger quantities. The Dörries VT 28 is designed for planetary carriers and large engine housings. Smaller machines for more compact engine components and housings will follow in 2025.

What about service and spare parts supply for the Dörries VCE series?

Quack: Our machines have been in use for 30 to 70 years and are looked after by a support team in Mönchengladbach (western Germany). The service also includes follow-up training – also in view of the shortage of skilled labour. We’ll continue to support the Dörries VCE series, just as we still handle old Schiess and Wotan systems that have long since been discontinued.

What does Starrag expect from the new high-performance direct table drive and the introduction of new hydrostatic guide systems?

Quack: The water-cooled direct drive in the rotary table enables more dynamic positioning and faster start-up. We’ll also continue to use hydrostatic guides in all linear axes, primarily in the RAM, to dampen vibrations and ensure high precision. A new hydrostatic system, which has also proven itself in Droop+Rein machining centres, ensures stable gaps and better geometry control. It reacts more robustly to temperature fluctuations and changes in viscosity.

Cool and dynamic

The water-cooled 98 kW direct drive in the rotary table of the Dörries VT 28 enables dynamic positioning and reduces processing times.

What new functions and technoloogies are you also introducing?

Quack: The new Dörries VT machines feature flexible robot mould handling, minimum lubrication of the table bearings, digital IFM sensors for recording and analysing data and a Siemens One control system. The use of ultra-high-performance concrete (UHPC) instead of cast iron for the table base ensures low vibration and temperature stability. UHPC is characterised by its exceptional strength and durability. In order to machine high-temperature materials like titanium and Inconel quickly and reliably, we use a high-pressure coolant supply of up to 350 bar. It reduces the machining time and increases the tools’ service life. For complete machining, the machine’s already equipped with a 64 kW integrated water-cooled direct drilling and milling drive as standard.

But this huge investment in new technical equipment does have an impact on costs: Hand on heart: Will the machine be more expensive?

Quack: No, because we can significantly reduce costs through standardisation and higher quantities. For example, the new head interface improves the precise transmission of forces, movements and commands from the machine head to the mould and offers more functions than previous interfaces. As long as we can cover significantly more than 90 per cent of all requirements as standard, we offer fast delivery times at attractive prices.

With its high degree of standardisation, can the machine still be customised?

Quack: We offer a high degree of flexibility in workpiece automation and integration into flexible manufacturing systems (FMS). The standard version of the machine can be set up without a deep pit or, if the hall height is low, it can be optionally lowered into a pit. Our aim is not to individualise too much. The Dörries VT 28, for example, is designed as standard for a turning diameter of 2.6 metres and can be extended to 2.8 metres.

The best of both worlds:

The new Dörries VT 28 builds on the successful Dörries VCE series and adopts its proven features to offer maximum precision and efficiency in machining

What measures have been taken to reduce the Dörries VT 28’s carbon footprint?

Quack: We reduce energy consumption through numerous measures like using special cement with its good technical and ecological properties. The adaptation of the drives, minimum lubrication and the use of components of the highest efficiency class also pave the way for sustainability.

What further developments or improvements is Starrag planning for the future of the VT series?

Quack: We’re looking for field test customers for the first machines and will provide close support. We’ll use this customer experience for further development. The development process for the first machine size has now been completed, with further sizes to follow in 2025.