HEIDENHAIN TNC 406 - Manual (Page 134)

HEIDENHAIN TNC 406, TNC 416 113
6.5 P
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Helical interpolation
A helix is a combination of a circular movement in a main plane and a
liner movement perpendicular to this plane.
A helix is programmed only in polar coordinates.
Application
„ Large-diameter internal and external threads
„ Lubrication grooves
Calculating the helix
To program a helix, you must enter the total angle through which the
tool is to move on the helix in incremental dimensions, and the total
height of the helix.
For calculating a helix that is to be cut in a upward direction, you need
the following data:
Shape of the helix
The table below illustrates in which way the shape of the helix is
determined by the work direction, direction of rotation and radius
compensation.
Thread revolutions n Thread revolutions + thread overrun at
the start and end of the thread
Total height h Thread pitch P times thread revolutions n
Incremental total
angle IPA Number of revolutions times 360° + angle for
beginning of thread + angle for thread
overrun
Starting coordinate Z Pitch P times (thread revolutions + thread
overrun at start of thread)
Internal thread
Work
direction
Direction
Radius
comp.
Right-handed
Left-handed Z+
Z+ DR+
DR– RL
RR
Right-handed
Left-handed Z–
Z– DR
DR+ RR
RL
External thread
Right-handed
Left-handed Z+
Z+ DR+
DR– RR
RL
Right-handed
Left-handed Z–
Z– DR
DR+ RL
RR
Y
X
Z
CC