A smooth CAD curve may be exported or posted as many short line segments, and those segments can appear as facets in the cut. Compare source geometry, CAM tolerance, arc handling, post output, controller support, and mechanical evidence before tightening everything at once.
Confirm Whether the Posted Path Contains Arcs
Begin at the source curve. CAD may store an arc or spline mathematically, but export formats and CAM tolerance can convert it into short line or arc segments. Inspect the editable model and the exported file separately so that a faceted result is not blamed immediately on machine motion.
Trace Where Curves Were Flattened
Use tolerance at final physical size. A setting that is harmless on a small part can create a large file and uneven motion on a scaled design, while a loose setting can visibly flatten gentle curves. Compare chordal deviation and the smallest meaningful feature rather than selecting the smallest number available.
Separate Visual Faceting From Motion Faceting
Watch how CAM smoothing and the post-processor treat the curve. Smoothing can reduce tiny moves while changing corners; a post can output different arc formats or split arcs according to controller limits. Compare the posted code or a recognized backplot with the CAM display before cutting valuable stock.
Check Units, Plane, Direction, and Arc Mode
Controller buffering, streaming, acceleration, and segment length can turn a mathematically acceptable path into hesitant motion. Test a clean circle and a representative spline at more than one controlled speed. If facets remain at the same geometric positions, look upstream; if they change with speed, motion handling becomes more likely.
Use a Circle-and-Arc Validation File
Separate surface scallops from polygonal geometry. A faceted edge has straight chords or repeated directional changes, while stepover marks follow tool spacing on a 3D surface. Preserve the part orientation and compare the physical marks with node locations and posted segments.
Keep the Approved Geometry-to-Controller Chain
Release the curve with source and export revisions, units, tolerances, CAM smoothing, post version, controller context, and accepted coupon. Do not repair only the machine-side file; the editable source and export process must be able to reproduce the approved path.
