HEIDENHAIN SW 54843x-02 DIN Programming - Manual (Page 351)

HEIDENHAIN MANUALplus 620, CNC PILOT 640 351
4.26 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.
You can change the machining direction and the cutter radius
compensation (TRC) with the cycle type Q, the cutting direction
H
and the rotational direction of the tool (see following table). Program
only the parameters given in the following table.
O Plunging behavior (default: 0)
 O=0: Vertical plunging
 O=1: With predrilling
 If NF is programmed: The cycle positions the milling cutter
above the first hole position saved in NF, then plunges and
mills the first section. If applicable, the cycle positions the
tool to the next pre-drilled hole and mills the next section,
etc.
 If NF is not programmed: The tool plunges at the current
position and mills the section. If required, repeat this
operation for the next section, etc.
Cycle run for milling
1
Starting position (X, Z, C) is the position before the cycle begins.
2 Calculates the milling depth infeeds.
3 Approaches to safety clearance.
 If O=0: Infeed to the first milling depth.
 If O=1: Plunges to the first milling depth.
4 Mills the contour.
5  For open contour and slots with slot width equal to the cutter
diameter: Moves at feed rate to the next milling depth, or
plunges at rapid to the next milling depth and mills the contour
in reverse direction.
 For closed contours and slots: Lifts off by the safety clearance,
moves forward and approaches to the next milling depth, or
plunges to the next milling depth.
6 Repeats steps 4 and 5 until the complete contour is milled.
7 Returns to retraction plane RB.
Parameters—Milling
Contour milling G840
Cycle
type Cutting
direction
Direction
of tool
rotation
TRC Version
Cycle
type Cutting
direction
Direction
of tool
rotation
TRC Description
Contour
(Q=0) – Mx03 – Outside Up-cut
milling
(H=0) Mx04 Left
Contour – Mx03 – Outside Climb
milling
(H=1) Mx03 Left