HEIDENHAIN TNC 426, User Manual

Page: 180 / 502

154 6 Programming: Programming Contours
6.5 P
a
th Cont
ours — P
o
lar Coor
dinat
e
s
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.
Programming a helix
U
Polar coordinates angle:
Enter the total angle of
tool traverse along the helix in incremental
dimensions.
After entering the angle, identify the
tool axis with an axis selection key.
U
Coordinate
: Enter the coordinate for the height of the
helix in incremental dimensions.
U
Direction of rotation DR
Clockwise helix: DR–
Counterclockwise helix: DR+
U
Radius compensation RL/RR/R0
Enter the radius compensation according to the table
above.
Example NC blocks: Thread M6 x 1 mm with 5 revolutions
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
Always enter the same algebraic sign for the direction of
rotation DR and the incremental total angle IPA. The tool
may otherwise move in a wrong path and damage the
contour.
For the total angle IPA, you can enter a value from
–5400° to +5400°. If the thread has more than 15
revolutions, program the helix in a program section repeat
(see “Program Section Repeats,” page 344)
12 CC X+40 Y+25
13 L Z+0 F100 M3
14 LP PR+3 PA+270 RL F50
15 CP IPA-1800 IZ+5 DR-
Y
X
Z
25
40
5
270°
R3
CC