Tool vector
Spindle / tool Z-axis direction in machine coordinates (i, j, k).
Machine configuration
C rotates about Z on table, then A rotates about X on trunnion.
Results
- ⚠ Singularity: tool aligned with +Z — C is arbitrary.
- • Right-hand rule, positive rotation. Table rotary convention.
- • Roll about the tool axis is not constrained by two rotary axes alone.