Description

ELHA VTG 502 – Year 2021
ELHA VTG 502 CNC Vertical Turning Grinding Machine Center for the Complete Machining of Large Parts

Manufacturer: ELHA
Model: VTG 502
Year of construction: 2021
Condition: like new (used)
Functionality: fully functional

Grinding width: 5,000 mm
Workpiece weight (max.): 40 kg
Grinding height: 700 mm
Grinding wheel diameter: 650 mm
Table length: 5,000 mm
Grinding wheel width: 150 mm
Table height: 950 mm
Grinding spindle motor power: 36 W
Equipment:
rotational speed infinitely variable

ELHA VTG 502 Vertical Turning Grinding Machine Center

with integrated CNC-control Siemens Sinumerik 840D sl
for workpieces up to Ø 5.000 mm

ELHA VTG 502
Grinding, turning and drilling machine for the complete machining of large parts
„The final touch“ –
Contouring on a grand scale
The decisive operations always come at the end. Even with large parts, grinding is often the method of choice. However, because other processes are also required, ELHA has designed the VTG,
a customizable vertical machining centre for complete machining tasks.

The vertical large machining centre VTG from ELHA for
finishing large-format workpieces
by grinding, turning and drilling

Even with large-format workpieces, grinding is the first
choice for reliably producing the required quality in a
final, all-determining operation. If you choose the wrong
machine now, you risk immense damage towards the end
of the value-added chain – after all, grinding is supposed
to refine the workpiece and give it the final and above all
valuable quality. But grinding alone is not enough in many
cases: High-precision features for the ground surfaces
must be milled, drilled and turned in the same clamping
for economic reasons. A combination of metal-cutting
machining processes in one machine is the most effective solution.
Prioritization is important
However: What is the main task in this context and what
are the secondary requirements? Only those who know
the main task, i.e. who know what leads to a significant
increase in the value of the end product and what has
to be done „for better or worse“, will be able to achieve
an economical and effective compromise in the resulting
machine design. The answer to this question always has
a direct impact on
Characteristics of the frame components (cast, welded
or polymer concrete design, passive/active sag compensation)
Type of main spindle (tool holder, automatic balancing,
chip-in-spindle detection)
Type of guide elements (linear roller bearing guided or
hydrostatic)
Characteristics of the drive (indirectly via pinion and
rack and pinion/toothed wheel or directly via direct drives (ELHA SDD)

Type of measuring systems used
Coolant supply inside and outside as well as on pressure and quantity, temperature control and its preparation
Tool change methodology, with number of the tools,
their monitoring and additional equipment such as
dressers
Geometrically defined and indefinite in tailor-made
combination
ELHA-MASCHINENBAU has taken up the challenge of
combining several machining processes – after prioritization by the customer – in one vertical machining centre. The maximum benefit in terms of achievable quality,
required productivity and flexibility can only be achieved
for the customer with a solution tailored to the tasks at
hand.
In the present case, ring-shaped workpieces with a diameter between 2500 mm and 6000 mm are machined
on the ELHA VTG. On the one hand, machining with a
geometrically defined cutting edge is carried out by turning and drilling on the right-hand work unit, while on the
other hand the left-hand work unit is used to machine the
workpiece with a geometrically undefined cutting edge by
grinding. As an additional function, it is also possible to
carry out turning operations with the grinding unit.
Secret weapon in the table
However, the focus of the ELHA VTG is clearly on the
grinding of round bodies. As a „secret weapon“ for highprecision grinding of rings, ELHA uses the table drive concept „SDD“ – Segment Direct Drive – developed in-house.
This drive works similar to the principle of the magnetic
levitation train, in that permanent magnets mounted on
the table follow a magnetic field rotating around it. The
result is an absolutely symmetrical, uniform and above all
shock-free force input into the rotary table. With a positioning accuracy of ±1 arc second, high acceleration, high
torque and high control stiffness, this table can nevertheless be used for highly accurate and dynamic positioning
and interpolation processes. These features of the table
drive have an extremely positive effect on both drilling
and grinding processes. In this case, a magnetic chuck is
used as the chuck, which, together with the ELHA-SDD,
represents the perfect solution for clamping and machining with regard to grinding.
In addition to the innovative table drive concept, the frequency response analyzed machine architecture – consisting of a combination of polymer concrete and adjustable welded steel constructions – as well as the use of
hydrostatic guides in all axes, ELHA-MASCHINENBAU
guarantees the user to find the perfect machine for his
task

Even in its basic version, the VTG carries two working units – one for geometrically undefined grinding
work (supplemented by turning functionality if required)
and one for geometrically defined work using turning and
drilling