HEIDENHAIN CNC Pilot 4290 V7.1 - Manual (Page 245)

HEIDENHAIN CNC PILOT 4290 245
4.22 Thr
e
ad Cy
cles
Starting angle C: At the end of the “run-in path B” the spindle is at
the “starting angle C” position.
Feedforward: G31 does not switch the feedforward off. You can
switch the feedforward off and on again in separate NC blocks (see
“Velocity feedforward G918” on page 307).
You influence the thread cutting with the smooth threading (see
“Thread switch G933” on page 239).
Run-in length: B = 0.75 * (F*S)² / a * 0.66 + 0.15
Run-out length: P = 0.75 * (F*S)² / e * 0.66 + 0.15
„ F: Thread pitch in mm/revolution
„ S: Speed in revolutions/second
„ a, e: Acceleration in mm/s² (see “Acceleration at block start/block
end” in MP 1105, ...)
„ Feed rate stop becomes effective only at the end of a
thread cut
„ Feed rate override is not effective
„ Do not use the spindle override if the feedforward is
switched off!
„ Create thread with G95 (feed rate per revolution)
Cycle run
1 Accelerates to feed rate (line B).
2 Moves to end point of thread – run-out length P.
3 Decelerates (line P) remains at the end point of thread.