HEIDENHAIN TNC 320 User Manual page 199

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.
HEIDENHAIN TNC 320 199