R2: Rotary Axes; Brief Description - Siemens SINUMERIK 840D sl Function Manual

R2: Rotary axes

13.1

Brief description

13.1
Rotary axes in machine tools
Rotary axes are used on many modern machine tools. They are required for tool and
workpiece orientation, auxiliary movements and various other technological or kinematic
purposes.
A typical example of an application using rotary axes is the 5-axis milling machine. Only with
the aid of rotary axes can the tip of the tool be positioned on any point on the workpiece on
this type of machine.
Depending on the type of machine, many different demands are placed on a rotary axis. In
order that the control can be adapted to the various types of machine, the individual rotary
axis functions can be activated by means of machine data or special programming.
Rotary axes are always programmed in degrees. They are generally characterized by the
fact that they assume the same position after exactly one rotation (modulo 360 degrees).
Depending on the application in question, the traversing range of the rotary axis can be
limited to less than 360 degrees (e.g., on swiveling axes for tool holders) or may be unlimited
(e.g., when the tool or workpiece is rotated).
In many ways, the responses and features of rotary axes are identical to those of linear
axes. The following description of functions is limited to a description of the special features
of rotary axes and how they differ from linear axes.
Definition of a rotary axis
An axis can be declared as a rotary axis using the following axis-specific machine data
MD30300 $MA_IS_ROT_AX.
Geometry axes are defined as linear axes. Any attempt to define them as rotary axes will be
rejected with alarm 4200 (Geometry axis cannot be defined as rotary axis).
Only when an axis has been declared as a rotary axis can it perform or use the functions
described on the following pages (e.g., unlimited traversing range, modulo display of axis
position, etc.).
Several axes can be declared as rotary axes simultaneously.
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
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