HEIDENHAIN TNC 426 B, User Manual

Page: 131 / 362

115 HEIDENHAIN TNC 426 B, TNC 430
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.
Internal thread Work direction Direction Radius comp.
Right-handed Z+ DR+ RL
Left-handed Z+ DR– RR
Right-handed Z– DR– RR
Left-handed Z– DR+ RL
External thread
Right-handed Z+ DR+ RR
Left-handed Z+ DR– RL
Right-handed Z– DR– RL
Left-handed Z– DR+ RR
Programming a helix
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 of more than 15
revolutions, program the helix in a program section
repeat (see section 9.2 ”Program Section Repeats”).
ú
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.
ú
Enter the coordinate for the height of the helix in
incremental dimensions.
ú
Direction of rotation DR
Clockwise helix: DR–
Counterclockwise helix: DR+
ú
Radius compensation RL/RR/R0
Enter the radius compensation according to the table
above.
Example NC blocks
12 CC X+40 Y+25
13 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
6.5 P
ath Cont
ours — P
olar Coor
dinat
es
Gkap6.pm6 30.06.2006, 07:04 115
www.EngineeringBooksPdf.com