Heavy Duty Lathes and Turning Centres

Nowadays, Tacchi are one of the most appreciated manufacturers of medium and large heavy duty lathes in the world machine tool market.

Our production includes exclusively flat bed CNC heavy duty lathes.

Our models are industry 4.0 compatible, highly customizable, and built for medium to large applications in terms of weight and size.

The CNC lathe is a machine equipped with only two axes, X and Z. Depending on the requirements and the component to be machined, we are able to offer additional units to perform boring, milling, and grinding with a single set-up.

We have in our range machines that can reach 6 meters of turning diameter for a distance between centres that can even exceed 30 meters.

Thanks to our longtime experience, we set no limits for ourselves. We are open to study customer requests and offer the best tailor-made solutions allowing not only turning operations but also boring, milling, grinding and super-finishing.

The three ranges of CNC heavy duty lathes

Our offer to the market covers:
– Two-slideway lathes with monolithic bed;
– Four-slideway lathes with monolithic bed;
– Double bed heavy duty lathes.

In their standard configuration, these lathes are compact, solid, and simple and, thanks to a wide range of available accessories and devices, they can undertake a variety of machining applications, even the most complex ones.

They feature high spindle revolutions, with substantial power and torque values. All these technical elements allow excellent performance both in precision turning and heavy roughing operations.

One specific two-slideway lathe series incorporates a sliding bed configuration.

The main technical characteristics are the same as the common two-slideway lathes but with the difference of having the bed divided into two parts, a lower one on which the upper part slides.

As a result of this, the gap is adjustable in length to be able to machine parts with flanges or discs that otherwise would require lathes of a much larger size.

One of the most common applications of this type of heavy duty lathes is related to aerospace components.

Heavy_duty_lathes monolithic bed two slideway

Heavy duty lathes monolithic bed four slideway

This series of heavy duty lathes consists of 6 different models, each one with L and H variants, depending on the:

Turning diameters;
Weights supported;
Required spindle torques;
Expected performance.

Beyond the weights and dimensions of the component to be machined, one of the structural features of this Series of lathes is that the saddle moves on slideways that are independent from the other machine components, allowing it to perform operations of the tailstock to the chuck without interruption and interference due to the repositioning of the steady rests.

Heavy duty lathes monolithic bed 4 slideway

Two separate beds are the main feature of the DB Series: the first one supports headstock and tailstock, while the second one, separated from the first, supports the longitudinal turning saddle slides.

This allows to cover very large turning diameters (even up to 6.000 mm) and weights admitted between centres up to 320 tons.

The Power Generation industry is the most common application for these heavy duty lathes due to the high precision required on turbine rotors and generator shafts.

We have a range of 6 beds with different widths that can be combined according to the size and weight of the workpieces to be machined.

The main components such as bed, headstock, saddle and tailstock are made of EN-GJL-300 cast iron, which is what eliminates internal stress which is possible on units with fabricated steel structure. This guarantees the utmost rigidity and stability of these heavy duty lathes even in the heaviest working conditions.

Complementary configurations

In addition to turning, Tacchi’s heavy duty lathes can be configured to perform multiple operations, including boring, milling and grinding to produce even complex-shaped components in a single set-up.

This solution allows for reducing the dead time necessary for repositioning the workpiece, increasing available floor space for additional machines capable to carry out complementary operations, and, last but not least, a reduction of skilled labour workforce.

All of the above results in higher quality and productivity.

We can complete the supply with the most suitable steady rests based on the size and the shape of the components, in various configurations: closed-type, C-type, bridge-type, self-centering or hydrostatic.

Most common applications:

Boring

Tacchi has a long and proven experience in internal turning applications for heavy duty lathes with anti-vibration boring bars. Over the years, we have developed more and more stable and rigid saddles and boring bar supporting structures, to be able to use boring bars with size-length ratios up to 16xØ.

Milling

We can offer several solutions for milling on heavy duty lathes.

The simplest and most practical one is a device to be mounted directly on the tool holding unit. Once the milling mode is selected, the machine switches the spindle rotation into a real programmable axis, identified as the C axis, capable of interpolating with the other axes.

For more challenging applications, our lathes can be equipped with a real milling column.

This can be configured with:

– Y axis programmable for the simultaneous interpolation with the other three machines axes X, Z, and C;
– C axis switching the spindle rotation into a real programmable additional axis, capable of interpolating with the other axes. We can also have some models of heavy duty lathes available even with four or five axes simultaneously interpolating to the machine, for example, crankshafts and other similar components;
– B axis for the radial or axial or even angular orientation of the spindle.

Grinding

Our heavy duty lathes can be equipped with various grinding devices, for either external or internal operations.

As for the external grinding applications, we have various solutions available ranging from simple devices, with a wheel with a diameter of 300 mm or 400 mm max., to be mounted on the turning units, up to real grinding heads with 1000 mm wheel diameter.

For internal machining, our proposal is necessarily more customized, having to consider, in addition to the diameter to be machined, the depth of grinding, and hence a verification of the structural machine components.

To complete the supply, we have available various wheel dressing devices, emulsion coolant plants with different flow rates depending on the kind of operation, several self-cleaning drum or paper filtering units to keep the emulsion in perfect conditions, telescopic covers for bedways and other parts of the machine to be preserved.

Customization of the CNC lathe

We can always study and offer other solutions and we are committed to achieving to best productivity targets for all our customers.

For years Tacchi has been able to design and build very complex CNC lathes, also equipped with single or double hydrostatic saddles.

In addition, we can provide high-level automation systems for tool storage or even pallet changing systems with the programmable replacement of the cutting units.

Our heavy duty lathes are available with several splash guard solutions or with total enclosure configuration, which can be completed with air filtration and suction devices.

For more information, contact us!

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