Today’s turning centers are designed for extreme precision machining as in the case of Swiss-type machines, or for heavy duty cutting from multi-axis tools on variable spindles. But modern turning centers are often constructed to perform multiple operations, including milling, cutting, and sanding to enhance cycle-time reduction and high-volume production. While they have been around for a number of years, these mill-turn machines continue to evolve with market needs.
This year reportedly has been a robust one for Swiss-type lathes, which are being leveraged for small precision and highly complex parts. Swiss machines offer sliding headstocks, allowing precise tool approaches, while reducing tool-to-workpiece distances, and their collet design allows them to perform high-precision cutting rapidly. Further, the addition of multiple tooling combines or sequences operations more efficiently, allowing one Swiss machine to turn, mill, drill, cut, and otherwise complete the application relatively quickly.
However, CNC Swiss machines can be expensive, as the high-precision, tight-tolerance operations raise costs due to demanding workpiece variables. Many machine tool manufacturers have sought ways to combine high-precision milling and cutting on conventional-style turning machines.
The DMG Mori/Seiki series of NT turn-mill centers allows manufacturers to machine workpieces via a wide range of tools while delivering high-speed spindle operation and precision cutting capabilities. These large machines can perform a variety of machining operations on a variety of workpieces using variable collets. In this manner, the center can handle a series of operations for complex parts that require different passes, from delicate, complex, high-precision cutting, to heavy-duty milling.
Additionally, the NT series uses DMG-developed technology to ensure heightened precision, including the direct drive motor (DDM) and driven at the center of gravity (DCG) design. The DDM uses a rotary system to power the spindle rotation, which DMG Mori/Seiki says reduces maintenance needs on traditional gear-driven systems. The DCG system also reduces rotational variation and vibration, resulting in higher precision. The mill-turn centers are thus able to perform higher-speed turning operations with a variety of tools.
Watch the video for more information on the NT series of mill-turn solutions.
Absolute Machine Tools has also designed a conventional turn-mill system to make turning options more robust in the QuickTech TT-42/60 CNC turning and milling centers. The TT centers have four spindles, with two of these devoted specifically to turning. The machines can operate on 42 mm or 60 mm bar.
Each turning spindle has a devoted three-axis tooling system, allowing for a suite of tools to service the various needs of the workpiece. The TT turning capabilities include a large number of tools devoted to turning, with four for internal diameter (ID) and six for outer diameter (OD), three axial live tool heads, and three radial live tool heads on the main tool post. The sub-tool post features four OD and five ID turning tools, along with three axial live tool heads, and three radial live tool heads. A quick-change tooling system is in place to ensure the tools move quickly during shifts.
The TT-42 tools are mounted on flat-bed gang slides to allow for multi-axis approach to the workpiece, reducing the bulk associated with slant-bed turning, which requires clearance standards that lead to crowding. With enhanced operator access to the tooling area, users can have a cleaner turning experience that maximizes oversight and precision.
Take a look at the TT-42 in action in the video below.