Groove Geometry Lab v2.1

For one-way raster, neighboring tracks remain parallel and their signed gap at fixed axial X is fill interval − surface speed × line period. For alternating raster, this gap varies along the line and is shown at the beginning/middle/end. Signed gaps can become negative or wrap around the circumference; they are not direct predicted Ra or measured ablation depths. Repetition reruns the four-line pattern at later rotational phases; the unwrapped panel shows the first four lines, while the animation includes repeated patterns. The displayed shaft rotates at the stated rate in simulated time; time scale changes the playback rate only, not the calculated geometry. Marking turnaround delay assumes the beam is off.

The model assumes an ideal rotary indexer at constant RPM, laser scanning along the shaft axis, four hatch lines, an ideal circular cylinder, synchronized motion, and constant nominal scanner velocity. It does not compute encoder phase error, dynamic focus corrections, gear backlash, beam-quality variation, or true 3D spot deformation. ID entry uses ideal centerline ray intersections with a cylindrical bore; finite apertures, scanner steering limits, dynamic focus, and beam clipping require separate validation. Visualized pulse dots are selectively decimated for rendering and do not imply missing physical pulses.