HEIDENHAIN CNC Pilot 4290 - Manual (Page 372)

7 Parameters 360
7.5 Mac
hining P
a
ra
met
ers
Predrilling - Traverse modes/Safety clearance
■ Approach for predrilling [ANB]
■ Traverse to tool change point [ABW]
Entries for retracting a tool:
■ 1: Simultaneous, X and Z direction
■ 2: First X direction, then Z
■ 3: First Z direction, then X
■ 6: Coupled motion, first X, then Z
■ 7: Coupled motion, first Z, then X
Approach and departure are in rapid traverse (G0).
■ Safety clearance to workpiece blank [SAB]
■ Internal safety clearance [SIB] – for deep-hole drilling (retraction
distance B for G74).
Predrilling - Machining
■ Drilling depth ratio [BTV] – TURN PLUS checks the 1st and 2nd
drilling step. The predrilling step is performed with:
BTV <= BT / dmax
■ Drilling depth factor [BTF] – 1st drilling depth for deep-hole drilling
cycle (G74):
bt1 = BTF * db
■ Drilling depth reduction [BTR] – Reduction for deep-hole drilling
cycle (G74): bt2 = bt1 – BTR
■ Overhang length - predrilling [ULB] – Through-drilling length