Innovative turning process for vertical lathes

Author Robert Weinstein
May 21,2018 - 03:45pm

Competition in the automotive industry is driving the need for higher-quality parts and lower manufacturing costs. All aspects are affected, including turning.

The Germany-based toolmaker Vandurit GmbH has addressed this challenge with its development of the rollFEED turning process. Vandurit has, in turn, collaborated with EMAG Salach (Germany) GmbH to use rollFEED exclusively with the vertical turning centers that EMAG builds. The process, which works with chuck diameters as large as 500mm (19.685"), provides a third axis and can be retrofitted to existing EMAG centers.

A major challenge the companies faced was satisfying customers’ demand for processes that helped them machine parts with increasingly complex geometries. Existing processes required a lot of insert changes to meet the surface requirements of the parts.

As an insert moves across the workpiece’s surface, the point of contact along the tool’s cutting edge moves. Image courtesy of EMAG USA.

Vandurit found that adding the third axis to the turning process allowed the insert to move while the part was being machined. “Now, a specially shaped rollFEED insert consisting of radial segments passes along the various sides of the part, one after the other,” explained Maurice van den Hoonaard, Vandurit’s managing director.

The capability provided by this third axis enables the turning tool to pivot. The machine’s X and Z axes compensate for any center offset that results from the pivoting.

In addition, as the rollFEED insert moves across the surface of the workpiece, the point of contact along the tool’s cutting edge moves. “Due to the uniformly or variably sized machining radius segments, it is possible to work with significantly higher feed rates,” van den Hoonaard said. “In addition, the surface quality is better, all the way into the corners.”

Another significant area of improvement is speed. According to Peter Loetzner, EMAG LLC USA’s president and CEO, the rollFEED process is much faster—up to 90 percent—than turning operations that require several tools over many steps. “A complete machining process from three component sides is now possible with only one type of insert,” he said. “As a result, the number of different tools used in production is lower, which makes many tool changes redundant—a true cost killer.” Among the contours that can be produced are end faces and cylindrical surfaces, chamfers, and convex or concave surfaces.

For more information about EMAG LLC USA, Farmington Hills, Mich., call (248) 477-7440 or visit

Related Glossary Terms

  • centers


    Cone-shaped pins that support a workpiece by one or two ends during machining. The centers fit into holes drilled in the workpiece ends. Centers that turn with the workpiece are called “live” centers; those that do not are called “dead” centers.

  • chuck


    Workholding device that affixes to a mill, lathe or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated. May also be fitted to the machine table to hold a workpiece. Two or more adjustable jaws actually hold the tool or part. May be actuated manually, pneumatically, hydraulically or electrically. See collet.

  • feed


    Rate of change of position of the tool as a whole, relative to the workpiece while cutting.

  • turning


    Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.