Kinematic configuration
The post defines the 4th and 5th axes: type (head or table), rotation vectors, pivot points, limits and preferred solution. These must match the controller's kinematic data and the NX machine model.
TCP output by controller
| Controller | TCP on | Tilted plane (3+2) |
|---|---|---|
| Siemens SINUMERIK | TRAORI | CYCLE800 |
| FANUC | G43.4 / G43.5 | G68.2 + G53.1 |
| Heidenhain | M128 / FUNCTION TCPM | PLANE SPATIAL |
Example: Siemens 5-axis output
; OP30 SWARF FINISH
T="BALL_6"
M6
D1
TRAORI
G54
G0 X20 Y-15 Z40 A3=0 B3=-0.5 C3=0.866
G1 Z5 F2000
...
TRAFOOFVector (A3/B3/C3) or rotary angle output depends on controller setup and post choice. For 3+2 operations, CYCLE800 parameters depend on the machine's swivel data set.
Rotary solution and retract logic
- Choose the preferred solution (e.g. positive B) within limits.
- Detect when a path will exceed a limit and plan a retract, re-orient and re-engage.
- Avoid unnecessary rotary unwinds between operations.
- Linearise near singularities to avoid sudden rotary flips.
Verify with ISV
Building a matching NX machine model with CSE simulation allows the posted G-code to be simulated inside NX, catching limit, collision and kinematic errors before the program reaches the machine.
In NX 5-axis work, post and machine model should be developed together.
NX 5-axis posts
See our CNC post processor development service and 5-axis kinematics configuration.