Typical applications
Impellers and blisks, turbine blades, ports, deep mould cavities, swarf-cut walls, and aerospace structural parts with twisted surfaces.
Challenges specific to simultaneous motion
| Challenge | Post solution |
|---|---|
| Singularity (tool parallel to a rotary axis) | Avoid or smooth rotary flips; hold the non-determined axis |
| Rotary limit reached mid-path | Plan retract, rewind and re-entry |
| Feedrate distortion from rotary motion | Inverse time or TCP feed mode |
| Large rotary change on a short move | Linearise or subdivide to keep the tool on path |
| Controller block processing speed | High-speed mode and suitable output tolerance |
Example: TCP output with vectors
(FANUC G43.5 - tool axis direction as vectors)
G43.5 H8
G01 X20.512 Y-4.118 Z12.004 I0.2588 J0. K0.9659 F1500.
X20.874 Y-3.902 Z11.882 I0.2672 J0.0214 K0.9634
...
G49With vector output, the controller computes rotary angles itself. With angle output (for example G43.4), the post computes them. Both approaches need correct machine kinematics.
Smooth motion matters
Small rotary jumps cause marks on finished surfaces. The post keeps rotary motion continuous, avoids unnecessary direction changes and outputs enough precision for the controller to interpolate smoothly.
Verification
Simultaneous programs should always be simulated on the full machine model using the posted G-code, including fixtures, holders and extended tools.
In simultaneous 5-axis, smoothness is accuracy.
Simultaneous 5-axis posts
See our CNC post processor development service and rotary axis kinematics.