HEIDENHAIN CNC Pilot 4290 V7.1 - Manual (Page 240)

240
4.22 Thr
e
ad Cy
cles
Thread cycle G31
G31 machines simple threads, successions of threads and multi-start
threads with G24-, G34- or G37-Geo. The CNC PILOT uses the tool
definition to distinguish between external and internal threads.
Run-in length B: The slide requires a run-in distance at the start of
thread in order to accelerate to the programmed feed rate before
starting the actual thread.
Run-out length P: The slide needs an overtravel at the end of the
thread to decelerate again. Remember that the paraxial line P needs
overtravel even with an oblique thread run-out.
Example: G31, part 1
. . .
FERTIGTEIL [FINISHED PART]
N 2 G0 X16 Z0
N 3 G52 P2 H1
N 4 G95 F0.8
N 5 G1 Z-18
N 6 G25 H7 I1.15 K5.2 R0.8 W30
N 7 G37 Q12 F2 P0.8 A30 W30
. . .
BEARBEITUNG [MACHINING]
N 33 G14 Q0 M108
N 30 T9 G97 S1000 M3
N 34 G47 P2
N 35 G31 NS5 B5 P0 V0 H1
N 36 G0 X110 Z20
N 38 G47 M109
. . .
Parameters
NS Block number (reference to basic element G1 Geo for
successions of threads: block number of the first basic
element)
I Maximum infeed
B Run-in length—no input: Run-in length is calculated from
adjacent undercuts or recesses. If they does not exist, the
thread starting length from machining parameter 7 applies.
P Run-out length—no input: Run-out length is calculated from
adjacent undercuts or recesses. If they does not exist, the
thread run-out length from machining parameter 7 applies.
D Cutting direction (reference: definition direction of basic
element)—(default: 0)
„ D=0: Same direction
„ D=1: Opposite direction
V Type of infeed (default: 0)
„ V=0: Constant cross section for all cuts
„ V=1: Constant infeed
„ V=2: With distribution of remaining cuts First infeed =
Remainder of the division of thread depth/cutting depth.
The last cut is divided into four partial cuts: 1/2, 1/4, 1/8 and
1/8
„ V=3: Infeed is calculated from the pitch and spindle speed
H Type of offset for smoothing the thread flanks (default: 0)
„ H=0: Without offset
„ H=1: Offset from left
„ H=2: Offset from right
„ H=3: Tool is offset alternately from the right and left
Q Number of air cuts after the last cut (for reducing the cutting
pressure in the thread base)—(default: 0)
C Starting angle (thread start is defined with respect to
rotationally nonsymmetrical contour elements)—(default: 0)