HEIDENHAIN SW 54843x-02 DIN Programming - Manual (Page 306)

306 DIN programming
4.21 Under
c
ut cy
cles
Undercut according to DIN 509 E with cylinder
machining G851
G851 machines the adjoining cylinder, the undercut, and finishes with
the plane surface. It also machines a cylinder start chamfer when you
enter at least one of the parameters Cut-in length (1st cut length)
or Cut-in radius (1st cut radius).
The control calculates unentered parameters from the diameter of the
cylinder in the standard table (see "Undercut cycle G85" on page 304).
Blocks following the cycle call
Example: G851
%851.nc
[G851]
N1 T2 G95 F0.23 G96 S248 M3
N2 G0 X60 Z2
N3 G851 I3 K15 W30 R2 B5 RB2 WB30 E0.2 H1
N4 G0 X50 Z0
N5 G1 Z-30
N6 G1 X60
N7 G80
END
Parameters
I
Undercut depth (default: value from standard table)
K Undercut length (default: value from standard table)
W Undercut angle (default: value from standard table)
R Undercut radius (default: value from standard table)
B Cut-in length (1st cut length)—no input: No chamfer machined
at start of cylinder
RB Cut-in radius (1st cut radius)—no input: 1st cut radius is not
machined
WB 1st cut angle (default: 45°)
E Reduced feed for machining the undercut (default: active feed
rate)
H Type of departure (default: 0):
 0: Tool returns to the starting point
 1: Tool remains at the end of the plane surface
U Grinding oversize for the area of the cylinder (default: 0)
N.. G851 I.. K.. W.. /Cycle call
N.. G0 X.. Z.. /Corner point of cylinder start chamfer
N.. G1 Z.. /Undercut corner
N.. G1 X.. /End point of plane surface
N.. G80 /End of contour definition
 Undercuts can only be executed in orthogonal, paraxial
contour corners along the longitudinal axis.
 Cutting radius compensation is active.
 Oversizes are not taken into account.