HEIDENHAIN CNC Pilot 4290 V7.1 - Manual (Page 589)

HEIDENHAIN CNC PILOT 4290 589
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Centric predrilling – Oversizes
Centric predrilling – Approach and departure
Oversizes
Point angle tolerance [SWT]
If the drilling limitation element is a diagonal element, TURN
PLUS prefers using a twist drill with suitable point angle. If no
suitable twist drill is available, an indexable-insert drill is
selected for the predrilling operation. SWT defines the
permissible point angle tolerance.
Drilling oversize – Diameter [BAX]
Machining oversize on drilling diameter (X direction – radius
value).
Drilling oversize – Depth [BAZ]
Machining oversize on drilling depth (Z direction – radius value).
BAZ is not considered if:
„ A subsequent inside finishing operation is not possible
due to the small diameter.
„ “dimin < 2* UBD2” in the finish-drilling step for blind
holes.
Approach and departure
„ Traverse for predrilling [ANB]
„ Traverse for tool change [ABW]
Approach/departure strategy:
„ 1: Move simultaneously in X and Z directions
„ 2: First X, then Z direction
„ 3: First Z, then X direction
„ 6: Coupled motion; X precedes Z direction
„ 7: Coupled motion; Z precedes X direction