Circular arc g16 with tangential connection, Helical interpolation, Polar radius, polar angle of the arc end point – HEIDENHAIN iTNC 530 (340 49x-01) ISO programming User Manual
Page 197: 5 p a th cont ours—p o lar coor dinat e s

HEIDENHAIN TNC iTNC 530
197
6.5 P
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ours—P
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Circular arc G16 with tangential connection
The tool moves on a circular path, starting tangentially from a
preceding contour element.
Programming
8
Polar coordinates radius R: Distance from the arc end
point to the pole I, J
8
Polar coordinates angle H: Angular position of the arc
end point
Example NC blocks
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:
N120 I+40 J+35 *
N130 G01 G42 X+0 Y+35 F250 M3 *
N140 G11 R+25 H+120 *
N150 G16 R+30 H+30 *
N160 G01 Y+0 *
The pole is not the center of the contour arc!
X
Y
40=I
35=J
30°
120°
R30
R25
16
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 H
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)
Y
X
Z
I,J