HEIDENHAIN TNC 360 User Manual - Manual (Page 117)

5-33 TNC 360
5 Programming Tool Movements
Fig. 5.40: The shape of the helix determines the direction of rotation
and the radius compensation
Fig. 5. 39: Helix: a combination of circular and linear paths
Y
X
Z
CC
5.5 Path Contours – Polar Coordinates
Work direction
Z+
Z+
Z-
Z-
Rotation
DR+
DR-
DR-
DR+
Radius comp.
RR
RL
RL
RR
Internal thread
Right-hand
Left-hand
Right-hand
Left-hand
Helical interpolation
A helix is the combination of a circular movement in
a main plane and a linear movement perpendicular
to the plane.
A helix is programmed only in polar coordinates.
Applications:
You can use helical interpolation with form cutters
to machine:
• Large-diameter internal and external threads
• Lubrication grooves
Input
• Total incremental angle of tool traverse on the helix
• Total height of the helix
Input angle
Calculate the incremental polar coordinate angle IPA as follows:
IPA = n
. 360°; where
n = number of revolutions of the helical path.
For IPA you can enter any value from –5400° to +5400° (n = ±15).
Input height
Enter the helix height H in the tool axis. The height is calculated as:
H = n x P,
n = number of thread revolutions
P = thread pitch
Radius compensation
Enter the radius compensation for the helix accord-
ing to the table at right.
Work direction
Z+
Z+
Z-
Z-
Rotation
DR+
DR-
DR-
DR+
Radius comp.
RL
RR
RR
RL
External thread
Right-hand
Left-hand
Right-hand
Left-hand