Automatic Turning Expands Into All Its Variations

This horizontal turning center provides different modular expansion options for complete six-sided machining of workpieces, from the two-turret version using the TWIN concept through to automatic lathes with three turrets and a B-axis for production demand.

The brand name SPRINT in the DMG/Mori Seiki USA (Hoffman Estates, IL) portfolio continues to be synonymous with premium-class high-speed automatic turning. But the only thing this new machine has in common with its predecessor series is its name.

The SPRINT 50 has been radically re-designed as a platform concept that now offers the perfect basis for different expansion options, starting with the twin turret version with up to two Y-axes and on through to a model with three turrets and a B-axis.

In other words, this machine promises an enormous plus in efficiency and flexibility in every possible area of application.

This is true in particular for the two-turret version, thanks to the integrated TWIN concept and due to the (patented) cross traversable counter-spindle/tailstock combination.

It says a lot about the high ambitions for the latest innovation from the Gildemeister Turning Association (Bielefeld, Germany) if a graduated (Swabian) engineer such as Dr.Ing. Jürgen Walz, the managing director of the Gildemeister Drehmaschinen GmbH (Bielefeld, Germany), allows DMG/Mori Seiki to quote him using such bold words as, “In the future any user that objectively assesses the technical characteristics and their benefits will certainly decide on our SPRINT 50 wherever high-speed automatic turning is concerned.”

This automatic turning machine is the prelude to a whole new series. As an overall project strategy, this automatic turning machine constitutes the entry into a completely new model platform.

Dr. Walz goes on to explain, “Up to now our turret machines for production and automatic turning have been divided into different series with three tool holders in the case of the former SPRINT series, or rather two turrets in the TWIN models.”

He continues, “This new generation will remove these boundaries and therefore replace both predecessor series in the respective design size and will itself cover all requirements of both production turning (chuck-held or from the bar) as well as automatic turning (only from the bar) at an even higher level.”

This exceptional diversity derives from a modular high-tech building block concept which allows the new series to be tailored individually to meet the needs and requirements of the customer.

In addition to the SPRINT 50 with its two turrets and up to two Y-axes, there is now also a three-turret version available with up to three corresponding Y-axes.

Another version with an integrated B-axis in the bottom turret will also be available as of autumn. And all preparations are already in the pipeline for a 65 version.

The general field of action of the SPRINT 50 is complete six-sided machining of workpieces up to 52 mm (2.05 in) in diameter and 600 mm (23.62 in) long with a speed of 7,000 rpm on both the main and the counter spindles.

The choice of working either with a chuck or from the bar in this range is in the last instance up to the user.

However, generally speaking the two-turret version will probably be used more for “either or” and the three-turret model more for bar material in everyday machining processes.

What you first notice where concept is concerned is its space-saving design with a 37 percent smaller footprint.

This compactness is achieved thanks to the vertical machine bed with its three-point support that in addition ensures optimum chip flow as well as offering the best framework conditions for both wet oil machining and dry machining.

PRODUCTION TURNING WITH THE TWIN CONCEPT FOR MAXIMUM FLEXIBILITY
The highlight of the different SPRINT 50 models with two tool mounts is the cross-traver­sable counter-spindle/tailstock combination, namely the (patented 1,500 times proven) TWIN concept, which increases the application possibilities enormously, as reference to the machining options of the two-turret machine demonstrates.

Utilization Option 1
Collision-free machining with two turrets and tailstock; 2 × 2-axis machining supported by the tailstock for long thin shafts; Y-axis for complex complete machining.

Utilization Option 2
The cross-traversable counter spindle makes front-sided machining of long workpieces on main and counter spindles possible; collision-free machining with two turrets; 2 × 2-axis machining.

Utilization Option 3
Collision-free 4-axis machining with two turrets and tailstock on a single workpiece – for long narrow shafts with a workpiece length of up to 600 mm (23.62 in).

Utilization Option 4 – 3-tool strategy (optional)
Tool 1 is set on the main spindle and tool 2 on the counter spindle (coupling operation in turret 1), while tool 3 is on the main spindle (turret 2). This enables 2 × 2 axes machining.

AUTOMATIC TURNING WITH 3 TURRETS AND (OPTIONAL) B-AXIS
The focus of the SPRINT 50 in the expansion options with three turrets, possible three Y-axes and additional (optional) B-axis is on their suitability for mass processing, which covers the ‘classic’ field of action of the previous models.

The generously dimensioned minus 2.5 deg to +182.5 deg swivel range of the B-axis also makes working at a negative angle possible.

FAST TURRETS FOR SHORT IDLE TIMES
Depending on the expansion stage, the two or rather three 12× VDI 25 turrets of the SPRINT 50 are equipped with driven tool stations throughout and each achieves a speed of 8,000 rpm.

The fast ramp-up times and dynamic switching of the turrets resulting in chip-to-chip times of now only 0.8 seconds are also particularly worth mentioning.

TRIFIX: EVEN MORE PRODUCTIVITY
Even in the standard version the 12x turrets are equipped as a basic principle with the TRIFIX® precision tool quick change interface in all tool stations. This means time-consuming adjustments inside the machine are a thing of the past.

Instead, the tools are positioned in the fixture during changeover via the TRIFIX® interface leading to a 35 percent reduction in set up times. This also impresses with a repeat accuracy in the micron range and a highly stable tool holder.

It also guarantees maximum precision and process reliability on the one hand, even with difficult workpiece materials, and a longer service life for the tools used on the other.

OPTIMUM WORK AREA
The benefits of the TRIFIX® effect gain additional value due to the fact that the overall ergonomics of the machine have been perfected.

The work area of the SPRINT 50, for example, has been designed in such a way that the turret is now within the operator’s reach allowing him direct access. This makes setting up simple and clean work with the added plus that it can be carried out quickly and efficiently.

Due to the interplay of flexibility and performance capacity in the process even medium-sized quantities can now be handled economically, where formerly only continuous runners were seen as the basis for amortization and called for in automatic turning.

TOP EFFICIENCY: CONTROL AND PROGRAMMING
There is one thing that cannot be disputed, whether you are talking about the electrical engineering branch with its need for drive shafts and special jet components or the car industry requiring steering linkages and small crankshafts (to name just a few representative examples).

As of now the SPRINT 50 will play a decisive role in all these and similar applications of automatic turning. This is also, and in particular, true thanks to the adapted control technology, namely the Siemens ShopTurn 3 G-control.

Highlights here include up to 60 percent shorter programming times due to innovative multi-channel programming, multi-channel 3D workpiece simulation and the flexibility offered by the unlimited combination of ShopTurn cycles and DIN functions.

This leads in the last instance to a 30 percent reduction in set up times ensuring even more flexibility for small and medium-sized batches.

The simplicity and clear structure of the integrated tool management rounds off the perfect overall image of the SPRINT 50 series just as much as the final mention of complete ShopMill functionality of the ShopTurn 3 G control from Siemens.

Other highlights of this advanced automatic turning center include:

• Optimum chip flow thanks to vertical machine bed with 3-point support for wet, oil and dry machining

• Patented work area concept (TWIN) with cross stroke of the counter-spindle/tailstock combination

• Space-saving design, 37 percent reduced footprint

• TRIFIX® precision tool quick change system, set up time reduced by 35 percent

• Highly-dynamic, fluid-cooled main and counter-spindle

• Two turret version: with up to two Y-axes

• Three turret version: with up to three Y-axes

• Sturdy roller guides on all linear axes

• Oil-air lubrication for turrets and spindle bearings

• Powered tools with 8,000 rpm

• Integrated tool loading device

• Fast and simple workshop programming with Siemens ShopTurn 3G and 3D simulation

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