This is a fully parametric stepped-cone light trap: a hollow conical shell with an internal “stair-step” baffle that forces stray light to bounce multiple times instead of reflecting back out. Use it for lamps, LEDs, sensors, camera/light enclosures, apertures, or anywhere you want a cavity to read as deep black.

NASA reference (why the geometry works)
NASA’s stray-light baffle work commonly models knife-edge vanes with beveled inner rims—e.g., “1 mm thick baffle vanes with 45-degree bevels… and 0.25 mm knife-edges…” NASA Technical Reports Server

This model follows the same core idea: sharp transitions + repeated bounces + matte surfaces.

Parameters (Customizer)

• bottom_inner_d / bottom_outer_d: small-end opening + outer diameter
• top_inner_d / top_outer_d: large-end opening + outer diameter (light entry)
• height: total length
• preset: fast / normal / detail / max_black
• override_step_count + step_count: force a specific number of baffle steps
• edge_overhang_deg (from vertical): ramp angle for the baffle edge
  • Best light-trap starting range: 35–50 (start at 45)
  • Try 55–65 if you flock/coat the inside
  • Avoid >70 unless you’ve tested your viewing angle + finish

Printing tips

• Orientation: print small end on the bed (small → large) if you want clean internal ramps with minimal/no supports
• Filament: matte black PLA/PETG/ABS; optional flat-black paint or flocking inside for maximum darkness
• Suggested: 3–5 walls, 0.16–0.24 layer height, 10–20% infill (or more for stiffness)

Notes

• More steps = more bounces = darker (at the cost of heavier geometry).
• If you need absolute “black hole” performance, surface finish matters: geometry + matte coating wins.