Execution of cycle – HEIDENHAIN TNC 640 (34059x-01) Cycle programming User Manual
Page 199

HEIDENHAIN TNC 640
199
8.2 C
Y
LINDER SURF
A
C
E (Cy
c
le 27
, DIN/ISO: G127
, Sof
tw
a
re
Option 1)
8.2 CYLINDER SURFACE (Cycle 27,
DIN/ISO: G127, Software 
Option 1)
Execution of cycle
This cycle enables you to program a contour in two dimensions and 
then roll it onto a cylindrical surface for 3-D machining. Use Cycle 28 if 
you want to mill guideways on the cylinder.
The contour is described in a subprogram identified in Cycle 14 
CONTOUR GEOMETRY.
In the subprogram you always describe the contour with the 
coordinates X and Y, regardless of which rotary axes exist on your 
machine. This means that the contour description is independent of 
your machine configuration. The path functions L, CHF, CR, RND and CT 
are available.
The dimensions for the rotary axis (X coordinates) can be entered as 
desired either in degrees or in mm (or inches). Specify this with Q17 
in the cycle definition.
1
The TNC positions the tool over the cutter infeed point, taking the 
allowance for side into account.
2
At the first plunging depth, the tool mills along the programmed 
contour at the milling feed rate Q12.
3
At the end of the contour, the TNC returns the tool to the set-up 
clearance and returns to the point of penetration.
4
Steps 1 to 3 are repeated until the programmed milling depth Q1 
is reached.
5
Then the tool moves to the set-up clearance.
C
Z
