Helical Interpolation - HEIDENHAIN ITNC 530 User Manual

Helical interpolation

A helix is a combination of a circular movement in a main plane and a
linear 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 an upward direction, you need
the following data:
Thread revolutions n Thread revolutions + thread overrun at
thread beginning and end
Total height h Thread pitch P times thread revolutions n
Incremental total Number of revolutions times 360° + angle for
angle IPA beginning of thread + angle for thread
overrun
Starting coordinate Z Pitch P times (thread revolutions + thread
overrun at start of thread)
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.
Work
Internal thread
direction
Right-handed Z+
Left-handed Z+
Right-handed Z–
Left-handed Z–
External thread
Right-handed Z+
Left-handed Z+
Right-handed Z–
Left-handed Z–
HEIDENHAIN iTNC 530
Radius
Direction
comp.
DR+ RL
DR– RR
DR– RR
DR+ RL
DR+ RR
DR– RL
DR– RL
DR+ RR
Z
Y
CC
X
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