Cycle run – HEIDENHAIN 530 (340 49x-07) Cycle programming User Manual
Page 234

234
Fixed Cycles: Cylindrical Surface
8.5 C
Y
LINDER SURF
A
C
E Outside Cont
our
Milling (Cy
c
le 39, DIN/ISO: G139,
Sof
tw
a
re
Option 1)
8.5 CYLINDER SURFACE Outside
Contour Milling (Cycle 39, 
DIN/ISO: G139, Software 
Option 1)
Cycle run
This cycle enables you to program an open contour in two dimensions 
and then roll it onto a cylindrical surface for 3-D machining. With this 
cycle the TNC adjusts the tool so that, with radius compensation 
active, the wall of the open contour is always parallel to the cylinder 
axis.
Unlike Cycles 28 and 29, in the contour subprogram you define the 
actual contour to be machined.
1
The TNC positions the tool over the starting point of machining. 
The TNC locates the starting point next to the first point defined in 
the contour subprogram, offset by the tool diameter (standard 
behavior).
2
After the TNC has positioned to the first plunging depth, the tool 
moves on a circular arc at the milling feed rate Q12 tangentially to 
the contour. If so programmed, it will leave metal for the finishing 
allowance.
3
At the first plunging depth, the tool mills along the programmed 
contour at the milling feed rate Q12 until the contour train is 
completed.
4
The tool then departs the ridge wall on a tangential path and 
returns to the starting point of machining.
5
Steps 2 to 4 are repeated until the programmed milling depth Q1 
is reached.
6
Finally, the tool retracts in the tool axis to the clearance height or 
to the position last programmed before the cycle (depending on 
MP7420).
You can define the approach behavior of Cycle 39 in 
MP7680, bit 16.
Bit 16 = 0:
Tangential approach and departure
Bit 16 = 1:
Move to depth vertically at the starting point of the 
contour without tangential tool approach and move up at 
the contour end point without tangential departure. 
