Complex Complete Machining with Compact Turn-Mill Spindle

The trend towards complete machining continues unbroken. On one hand, the diversity of products and configurations is growing across a multitude of different industries and this, in turn, leads to a reduction in lot sizes on an increasingly wider scale. In view of such conditions, complete machining in a single setup quickly becomes the only economic alternative. On the other hand, workpieces are getting more and more complex while at the same time placing higher demands on precision. Adding to this, global competition is aggravating the earnings situation in manufacturing plants.

To meet these demands, DMG MORI USA (Hoffman Estates, IL) has been revolutionizing turn-mill complete machining with their the CTX TC series machines that were first introduced eight years ago. These machining all-rounders have now entered their second series with the CTX gamma 2000 TC, a turn-mill machining center of the second generation that uses the new turning/milling spindle compactMASTER®.

The smaller CTX beta TC model is already in its second generation and larger sister machines CTX gamma 1250 TC and CTX gamma 2000 TC were developed in 2015. The outstanding features of these two turn-mills are the X-travel, which has increased by 5.9 in to 31.5 in, and the compactMASTER spindle of the B-axis, developed together with the Japanese engineers as a cooperation project. The unique selling point above all is that torque increased by 120 percent to 162.3 ft-lb.

With a diameter of 8 in, the length of the compactMASTER spindle has been reduced by 2.8 in so that it now measures only 17.7 in – and all this with 120 percent higher torque. The interplay of the 5.9 in larger X-axis (-1 / +30.5 in) and the 0.8 in longer Y-travel of ±8.3 in brings an enormous gain in freedom for users. It means, for example, that radial machining of workpieces with maximum diameters of 27.6 in is possible with 6.7 in long tools (with the B-axis in a vertical position). The second generation of the CTX gamma TC also has advantages where horizontal machining is concerned: workpieces measuring up to 11.8 in long can now be completely drilled out horizontally or hollow turned with no problem at all on the CTX gamma 2000 TC. The respective turning length is 80.7 in.

The core element of the two new CTX gamma TC models is still the B-axis with its swivel angle of ±120 deg, which is mounted on a highly stable travelling column and ensures milling performance right through to the field of 5-axis simultaneous machining. The machine concept has been radically revised with stability and precision in mind. The machines now have an integral thermal concept that includes integrated bed cooling, as well as cooling of the linear guides of the travelling column, the spindle motors and the drive of the B-axis. Combined with the MAGNESCALE magnetic measuring systems, the thermal displacement of the machine is now ≤ 10 µm.

The travelling column has also been redesigned. The U-shaped basic construction with 3+2 guide shoes in the Z-axis increases stability enormously, which has great impact on machining with the Y-axis. Linearity has been improved by over 60 percent to now stand at ≤ 2 µm. Another innovative feature is an up to 65 percent faster feed rate of 1,968.5 ipm in all axes. The machine can also be optionally equipped with a linear drive in the Z-axis that, with 1 g acceleration, increases the feed to 2,362.2 ipm and ensures maximum long-term accuracy; including a 5-year warranty granted for the linear drive.

These machines are equipped with 36 tool pockets in their standard version. This capacity can be increased optionally to 80, 120 or 180 tools. The user has the choice of a standard HSK-A63 or a Capto C6, Capto C8 or HSK-A100 tool holders. The optional counter-spindle also opens up the possibility of up to 5-axis simultaneous 6-sided complete machining, even for the most complex workpieces. Equipping the two second generation CTX gamma TC models with an optional lower turret as a second tool holder for 12 powered tools with up to 10,000 rpm transforms the machines into veritable 5-axis production centers. Optional steady rests up to SLU 6 with maximum clamping diameters of 19.7 in can be used instead of the second tool mount for the machining of shafts.

As turn-mill machining involves extremely complex processes, DMG MORI focuses its development work on the operation and programming of the turn-mill equipment. Exclusive technology cycles for, among other things, 5-axis machining in the field of application-related shop floor programming have already simplified the work involved enormously. Parameter-driven context menus that enable simple input of the parameters in the dialog box, as well as pre-defined and easy to learn input screens, mean that advanced programming skills are hardly required any more, not even in the turn-mill field. Another example of this is the new gearSKIVING cycle that enables eight times faster and top quality production up to DIN 7 of both straight-cut as well as helical-cut outer and inner spur gears, and spline shaft gearing compared to gear shaping. Even toothing on shoulders can be realized without any damage to the projecting edge, while surface structures for low-noise gears are possible virtually at the press of a button.

Where operation of the turn-mill machining centers is concerned, these machines use the enormous system intelligence of CELOS® and many different CELOS apps that relieve the operator of many problems, as well as guiding them through daily work by means of stored job order and work plans that can be visualized. Employees young and old can quickly learn to manage the dialog-based app operation and intuitive CELOS structure. Trainees can very quickly learn to operate the machines without any great need of training. CELOS also offers the possibility of using a SMARTkey® that organizes individual access rights so that only selected CELOS apps are made available to employees in accordance with their qualifications.

All of this makes CELOS a future-proof key for transition to the era of Industry 4.0. Using CELOS, job order, process and machine data can be managed, documented and visualized via a common user interface for workshop and office. CELOS also enables an open exchange of information with higher-level network structures via defined interfaces and completely integrates the machine tool into the shop organization.

DMG MORI USA, 2400 Huntington Boulevard, Hoffman Estates, IL 60192, 847-593-5400, Fax: 847-593-5433, us.dmgmori.com.