Even more efficient with eight spindles

The Esslingen multi-spindle specialists supplement the MS22C series by an 8-spindle CNC production automatic lathe MS22C-8. The modular eight-spindle machine built on the multi-spindle modular system can also efficiently machine highly complex workpieces that would have driven the previous multi-spindle machines normally equipped with six spindles to their limits.

The INDEX MS22C-8

The INDEX MS22C-8

The INDEX MS22C-8 CNC multi-spindle automatic lathe opens up additional opportunities for already unbeatably fast multi-spindle parts machining: Highly complex parts that even six-spindle machines have previously had to decline are no problem for the eight-spindle machine.

Two swiveling synchronous spindles for optimal rear end machining

INDEX CNC multi-spindle machines can be configured according to customer requirements in terms of the number of cross-slides, Y-axes, and synchronous spindles

INDEX CNC multi-spindle machines can be configured according to customer requirements in terms of the number of cross-slides, Y-axes, and synchronous spindles

Each of the eight symmetrically arranged spindles are assigned two cross-slides which can travel both on the X as well as on the Z-axis. Each cross-slide can be additionally equipped with a Y-axis. Added to that are up to two swiveling synchronous spindles for simultaneous rear end machining. Combined with a total of up to 16 cross-slides, the eight-spindle machine is therefore a true multi-talent even for highly complex machining. The speed of each of the eight spindles can be controlled separately. The fluid-cooled spindle drum keeps the thermal growth in the spindle carrier to a minimum. The eight spindles are cooled as needed using a reliable fluid cooling system. The advantage compared to the previous air-cooling approach is the higher power density in the spindle drum and the capability of energy recovery from the heated cooling fluid. In addition, the spindle bearing temperature can be kept at a low level, which also prolongs its service life and improves thermal stability.

The cross slides with integrated drive have a low-mass design with hydrostatic bearing support. They are appealing due to their low moment of inertia and the resulting high dynamics, which facilitates outstanding acceleration in practical application. The advantage of hydrostatic sliding guide in the feed axis (Z) is their outstanding damping characteristic that prevents the transfer of the machining vibrations to the adjacent slide via the headstock. This helps to mitigate vibration and rattling while workpieces are being machined – even when the most diverse machining processes are being performed concurrently by the eight spindles. For example, one spindle can be used for heavy-duty roughing while high-precision finishing takes place on another spindle without sacrificing surface quality. In addition, the hydrostatic bearing is wear-free – there is neither friction nor a stick-slip effect.

Another of the machine’s highlights is its double workpiece rear end machining capability, which is achieved using swiveling synchronous spindles that are locked into the end positions by three-part Hirth couplings. The high level of stiffness that this achieves also guarantees that even with bar diameters up to 24 mm, rear end machining operations with very high cutting volumes and simultaneously high machining precision can be performed.

The swiveling synchronous spindles stand out due to their outstanding dynamics, for example, the swivel movement to the rear end position occurs in less than 0.3 seconds. The advantage of the three-part Hirth coupling it is no longer necessary to electronically compensate at the end position. The mechanical lock ensures optimal stiffness and increases the positioning accuracy. This allows even highly complex components to be produced that require complex cut-off side machining.

Front-opening machine – diverse and various uses

The eight-spindle INDEX MS22C-8 can be operated both as a bar lathe as well as a handling machine. The advantage of the front-opening design for the operator is the excellent accessibility during setup and tooling. Moreover, there is the free chip flow down into the chip discharge chute. To save space, the INDEX engineers simply placed the control cabinet “on the machine”. This principle of integrating the control cabinet into the machine roof has been applied to INDEX multi-spindle machines for almost 15 years and has been very well received in the market. Along with its compact size, the machine also comes with higher power density.

The standard version of the machine, the INDEX MS22C-8, already offers diverse and numerous applications: it can be operated as an eight-spindle machine, as a double four-spindle machine or as a machine with double rear end machining. When operated as an eight-spindle machine, the drum indexing angle from spindle to spindle is 45°; if the machine operates with two times four spindles, the drum indexing angle is 90°. Results from double four-spindle machining: two finished parts are produced by the machine per work cycle.

The MS22C-8 in double four-spindle mode actually runs as two machines working with one another simultaneously in one housing. Every second tool station always has simultaneous access to the same tools.

In double rear end machining, there are six spindle positions available for front machining the workpiece and two spindle positions for rear end machining, and they all work simultaneously. With this approach, it is possible to machine the rear end of a workpiece during two drum indexing cycles.

Double four-spindle machine – an interesting upgrade option

Double four-spindle machine – an interesting upgrade option

When it comes to the machining sequence, the INDEX engineers have exhausted all options for further improving efficiency: After front machining, for which six spindle positions are available, the workpieces are picked up by two rear machining units and machined simultaneously on the rear end. Because rear end machining is done during two drum indexing cycles, up to six tools can be used for this simultaneously with the other spindles.

Of course, the MS22C-8 can also be used as a double four-spindle machine or with double rear end machining. Because all cross slides are located at the same travel angle to one another, free chip flow is guaranteed in each position. In addition, the user is completely free in tooling the cross-slides.

Catering to current market demands, which dictate that workpieces be discharged damage-free from the work area and at the same time have to be placed on pallets in the right position for later treatment, the Esslingen multi-spindle specialists also offer elegant optional solutions for the new eight-spindle MS22C-8: For example, machine-integrated handling with external stacking unit that ensures both destruction-free removal of parts from the machine – with connected measuring operations for the workpieces if needed. For example, the current workpiece data can be fed back via corresponding interfaces without delay so that the machine control can automatically correct its machining parameters.

The eight-spindle INDEX MS22C-8 CNC multi-spindle automatic lathe has many applications throughout all industries, ranging from the automobile industry to medical technology. It also produces small batches efficiently and economically. Another benefit for the user is that all standard tool holders and tool holder system interfaces can be used with the appropriate adapters (Capto, HSK, VDI, INDEX systems).

There are already a total of 27 machining tools available in the standard model, of which 16 can be used simultaneously. As usual with INDEX multi-spindle machines, the eight-spindle MS22C-8 can handle all technologies for turning centers, such as turning, drilling, milling, multi-edge turning, hobbing, tooth milling, deep-hole drilling or slotting.

Inherent energy efficiency optimizes energy consumption

For years all INDEX machines have obeyed the demand for reduced consumption. The INDEX MS22C-8 is no exception here and rates high with the following benefits: weight-optimized components for reducing energy consumption and for increasing the dynamic response; energy recovery by means of regenerative drives; energy shutdown of units that consume large amounts of energy after a user-defined time (standby mode); minimized friction based on optimally paired materials and low-friction bearings (hydrostatic circular guide); intelligent cooling principles for targeted cooling of the machine and reuse of waste heat. The INDEX cooling concept ensures that the spindles, hydraulics, and control cabinet are cooled constantly and that the heat can be supplied to a different application via a “cold water interface,” e.g., for service water heating or as process heat for other manufacturing steps.

Source INDEX-Werke GmbH & Co. KG