HEIDENHAIN TNC 620 User Manual page 465

Face milling: 3-D compensation with TCPM
Face milling is a machining operation carried out with the front face
of the tool. If the NC program contains surface normals and TCPM
or M128 is active, then a 3-D compensation is carried out in 5-axis
machining. In this case, the RL/RR radius compensation must not
be active. The TNC displaces the tool in the direction of the surface
normals by the sum of the delta values (tool table and TOOL CALL).
If there is no tool orientation set in the LN block, then the TNC
holds the tool vertically to the workpiece contour when TCPM is
active.
Further Information: Maintaining the position of the tool tip when
positioning with tilted axes (TCPM): M128 (option 9), page 452
If there is a tool orientation T defined in the LN block and M128
(or TCPM FUNCTION) is active at the same time, then the TNC will
position the rotary axes automatically so that the tool can reach
the defined orientation. If you have not activated M128 (or TCPM
FUNCTION), then the TNC ignores the direction vector T, even if it
is defined in the LN block.
The TNC is not able to automatically position the
rotary axes on all machines. Refer to your machine
manual.
Danger of collision!
On machines whose rotary axes only allow limited
traverse, sometimes automatic positioning can
require the table to be rotated by 180°. In this case,
make sure that the tool head does not collide with
the workpiece or the clamps.
HEIDENHAIN | TNC 620 | Conversational Programming User's Manual | 10/2015
Three-dimensional tool compensation
12
12.6
465