HEIDENHAIN SW 54843x-02 DIN Programming - Manual (Page 183)

HEIDENHAIN MANUALplus 620, CNC PILOT 640 183
4.1 Pr
ogr
amming in DIN/ISO mode
Contour programming
The "contour follow-up" function and contour-related turning cycles
require the previous description of the blank and finished part. For
milling and drilling, contour definition is a precondition if you wish to
use fixed cycles.
Contours for turning
 Describe a continuous contour.
 The direction of the contour description is independent of the
direction of machining.
 Contour descriptions must not extend beyond the turning center.
 The contour of the finished part must lie within the contour of the
blank part.
 When machining bars, define only the required section as blank.
 Contour definitions apply to the entire NC program, even if the
workpiece is rechucked for machining the rear face.
 In the fixed cycles, the defined contour is used to program
"reference values."
To describe workpiece blanks and auxiliary workpiece blanks, use
 G20 "Blank part macro" for standard parts (cylinder, hollow cylinder).
 G21 "Cast-part macro" for blank-part contours based on finished-part
contours. G21 is only used for describing workpiece blanks.
 Individual contour elements (such as are used for finished-part
contours) where use of G20 or G21 is not possible.
To describe finished parts, use individual contour elements and form
elements. The contour elements or the complete contour can be
assigned attributes accounted for during the machining of the
workpiece (example: oversizes, additive compensation, special feed
rates, etc.). The control always uses paraxial elements to close
finished parts.
For intermediate machining steps, define auxiliary contours.
Auxiliary contours are programmed in the same way as finished-part
descriptions. One contour description is possible per AUXILIARY
CONTOUR. An AUXILIARY CONTOUR is assigned a name (ID) that
can be referenced by the cycles. Auxiliary contours are not closed
automatically.
Use ICP (Interactive Contour Programming) for describing
blank and finished parts.