Path Contours - Fk Free Contour Programming (Option 19); Fundamentals - HEIDENHAIN TNC 620 User Manual

Programming contours | Path contours – FK free contour programming (option 19)
5.6 Path contours – FK free contour
programming (option 19)

Fundamentals

Workpiece drawings that are not dimensioned for NC often contain
unconventional coordinate data that cannot be entered with the gray
path function keys.
You can enter such dimensional data directly by using the free
contour programming function FK, e.g.
If there are known coordinates on or in proximity to the contour
element
If coordinate data refers to another contour element
If directional data and data regarding the course of the contour
are known
The control derives the contour from the known coordinate data
and supports the programming dialog with the interactive FK
programming graphics. The figure at upper right shows a workpiece
drawing for which FK programming is the most convenient
programming method.
Programming notes
You must enter all available data for every contour
element. Even the data that does not change must
be entered in every NC block—otherwise it will not be
recognized.
Q parameters are permissible in all FK elements, except
in elements with relative references (e.g. RX or RAN), or in
elements that are referenced to other NC blocks.
If both FK blocks and conventional blocks are entered
in an NC program, the FK contour must be fully defined
before you can return to conventional programming.
Program all of the contours before combining them
(e.g., with the SL cycles). You thereby ensure that the
contours are correctly defined and avoid unnecessary
error messages.
The control needs a fixed point that it can use as the
basis for all calculations. Use the gray path function keys
to program a position that contains both coordinates
of the working plane immediately before programming
the FK contour. Do not enter any Q parameters in this
NC block.
If the first NC block of an FK contour is an FCT or FLT
block, you must program at least two NC blocks with the
gray path function keys before it. This fully defines the
approach direction.
Do not program an FK contour immediately after a LBL
command.
You cannot combine the cycle call M89 with
FK programming.
HEIDENHAIN | TNC 620 | Klartext Programming User's Manual | 01/2022
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