Multi-Operation Machining:
Milling, turning, and grinding on one machine

On a milling/turning machine with the TNC 640, you can machine the complete workpiece at one time: milling, turning, milling, in whatever sequence is needed. The TNC 640 offers you powerful functions that enable you to switch the NC program as desired between turning and milling under program control. This enables you to decide with complete freedom how and when you want to combine the two machining methods.

The field-proven HEIDENHAIN lathe controls provide the software basis for the turning functions. So you also have contour elements unique to turning, such as recesses or thread undercutting. Besides the standard path functions you can also use FK free contour programming to easily create contour elements.

Simple Switching between Turning and Milling

You can use standard conversational commands to switch as desired under NC program control between the milling and turning modes. There are practically no limitations. The control switches modes regardless of the current axis configuration and the TNC 640 adopts all internally required changes:

  • Transition to diameter display
  • Setting the datum in the center of a rotary table
  • Locking the tool spindle and other machine-dependent functions

Programming as Accustomed

You can program the turning operations conveniently under dialog guidance in HEIDENHAIN conversational format. Besides the standard path functions you can also use free contour programming (FK) to define the turning contour. With FK, you can easily create contour elements that were not dimensioned for NC.What’s more, you also have the contour elements recess and undercut for turning operations. Intuitive help illustrations support you in the definition of these contour elements.

Tools for turning are defined in the same way as those for milling, while the TNC 640 offers the user comprehensive graphical support.

Even grinding operations can be programmed as usual with HEIDENHAIN Klartext dialog guidance. If the contour is available as a CAD file, then you can easily import it with the aid of the CAD Import function (option).

Milling, turning, and grinding cycles

HEIDENHAIN controls have always been known for their comprehensive and technologically advanced package of cycles. The cycles of the TNC 640 include multi-step, frequently recurring operations. While programming cycles, you enjoy dialog guidance and informative help images that illustrate the required parameters. In addition to the well-known TNC milling and drilling cycles, the TNC 640 also provides numerous turning cycles for roughing, finishing, recessing, thread turning, recess turning, and more. These turning functions are based on software from the longproven HEIDENHAIN turning controls, allowing you to program even complex turning operations with ease on the machine.

The TNC 640's more complex turning cycles employ the same techniques as those used for milling. As a result, TNC programmers can build on their prior knowledge to rapidly enter the world of turning operations on a milling machine without retraining. The control also features grinding cycles, including:

  • Define reciprocating stroke
  • Activate wheel edge
  • Profile dressing

Interpolation turning

Although you can create ring slots, recesses, tapers, or any turning contour using conventional turning operations, you can also take advantage of interpolation turning. In interpolation turning, the tool executes a circular movement using the linear axes. For outside turning, the cutting edge is oriented towards the circle center, and for internal turning, away from the center. By varying the circle radius and the axial position, any rotationally symmetric body can be produced, even in a tilted working plane.

Convenient control of facing heads

The TNC 640 makes it very easy to control facing heads. It enables you to produce any desired turning contours on non-rotationally symmetrical workpieces.