Operation Manual

HEIDENHAIN CNC PILOT 640 303
4.7 Drilling cycles
Operating mode for technology database access depends on the tool
type:
 Twist drill: Drilling
 Indexable insert drill: Predrilling
Cycle run
1 Position spindle to spindle angle C (in Manual mode, machining
starts from the current spindle angle)
2 If defined, move at rapid traverse to hole starting point X1
3 If defined, spot drill at reduced feed rate
4 Depending on through drilling variants V:
 Through-drilling reduction:
– Drill at programmed feed rate to position X2 – AB
– Drill at reduced feed rate to hole end point X2
 No through drilling reduction:
– Drill at programmed feed rate to hole end point X2
– Remain at end of hole for dwell time E, if defined
5 Retract
 If X1 is programmed, to hole starting point X1
 If X1 is not programmed, to starting point X
6 Move to the tool change point according to the G14 setting
If "AB" and "V" are programmed, the feed rate is reduced
by 50% during both pre-drilling and through-boring.