HEIDENHAIN CNC Pilot 4290 V7.1 - Manual (Page 270)

270
4.27 Milling Cy
cles
Approach and departure: For closed contours, the point of the
surface normal from the tool position to the first contour element is
the point of approach and departure. If no surface normal intersects
the tool position, the starting point of the first element is the point of
approach and departure. For figures, use D and V to select the
approach/departure element.
Pocket milling, roughing G845 – Fundamentals
G845 roughs closed contours. Choose one of the following plunge
strategies, depending on the milling cutter you are using:
„ Plunge vertically
„ Plunge at a pre-drilled position
„ Plunge in a reciprocating or helical motion
When “plunging at a pre-drilled position,” you have the following
alternatives:
„ Calculate positions, drill, mill. The machining process is
performed in the following steps:
„ Insert drill.
„ Calculate hole positions with “G845 A1 ..”.
„ Predrill with “G71 NF ..”
„ Call cycle “G845 A0 ..”. The cycle positions the tool above the
hole; the tool plunges and mills the pocket.
„ Drill, mill. The machining process is performed in the following
steps:
„ Drill a hole inside the pocket with “G71 ..”.
„ Position the milling cutter above the hole and call “G845 A0 ..”.
The tool plunges and mills the section.
If the pocket consists of multiple sections, G845 takes all the sections
of the pocket into account for drilling and milling. Call “G845 A0 ..”
separately for each section when calculating the hole positions
without “G845 A1 ..”.
Cycle run for deburring
1 Starting position (X, Z, C) is the position before the cycle begins.
2 Moves to the safety clearance and infeed to the first milling
depth.
3 „ J not programmed: Mills the programmed contour.
„ J programmed, open contour: Calculate and mills the “new”
contour.
4 Return to “retraction plane K.”
G845 takes the following oversizes into account:
„ G57: Oversize in X, Z direction
„ G58: Equidistant oversize in the milling plane
Program oversizes for calculating the hole positions and
for milling.