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Design Parametric Sacrificial Lens Cover (Polycarbonate Disc Family) PROJECT OVERVIEW I need an engineer/designer to create a family of sacrificial protective lens covers for generic optics / cameras / night-vision–style devices. These will be flat, clear discs (no optical power), designed to act as sacrificial windows in front of an objective lens to protect it from impact, debris, and environmental damage while minimizing image degradation. Primary manufacturing method will be laser-cutting or CNC-cutting from clear polycarbonate sheet. A secondary, “good enough” version using 3D-printed transparent PETG is a bonus. Design must be strictly utilitarian / performance-focused – no decorative elements. SCOPE OF WORK The freelancer will: Design a parametric CAD model for a family of flat circular sacrificial lens covers in multiple diameters. Provide manufacturing drawings suitable for: Laser cutting or CNC cutting from polycarbonate sheet (primary) Optional FDM 3D printing with transparent PETG (secondary) Ensure the design is: Mechanically robust Easy to manufacture at small scale Suitable for repeated outdoor use and impact exposure No branding, logos, or decorative details are required. LENS COVER SPECIFICATIONS Geometry Type: Flat circular disc (protective window, NOT an optical lens) Faces: Two flat, parallel faces (no curvature) Edge: Light chamfer or small radius to prevent chipping and aid handling Nominal Clear Diameters (family) Please design as a parametric family with these nominal diameters: 25 mm 30 mm 32 mm 35 mm 40 mm 44 mm 50 mm These should be easily adjustable in the model so additional diameters can be added later. Thickness Two standard thickness options: Standard: 1.5 mm Heavy Duty: 2.0 mm Model should support both thicknesses parametrically. Tolerances Diameter: ±0.10 mm (target) Thickness: as per stock sheet, but design assuming ±0.10 mm Flatness: good enough to avoid noticeable distortion for typical camera / NV use (no explicit tolerance needed, but faces must be flat and parallel in the model) Material Primary variant (recommended for production): Clear, UV-stabilized polycarbonate sheet Good impact resistance Good clarity Suitable for outdoor and temperature-varying environments Secondary / optional variant: Transparent PETG for FDM 3D printing Geometry identical to the polycarbonate disc Thickness and diameter as above Model should be printable flat on the build plate Optical Requirements (qualitative) No optical power (no focus, no curvature) Designed as a sacrificial window, not a precision lens Faces should be as flat and parallel as practical for minimal added distortion or ghosting Edge Treatment Add a small edge relief: Chamfer: 0.2–0.3 mm @ 45° or Fillet: 0.2–0.3 mm radius Purpose: reduce chipping and make discs more comfortable to handle and install. DELIVERABLES For the lens covers only (no housing required unless we add that as a follow-on): CAD Files Parametric master model (native CAD format if possible) STEP files for each size and thickness combination (e.g., 25×1.5, 25×2.0, 30×1.5, etc.) 2D Drawings PDF + DXF for each nominal diameter Include: diameter, thickness, tolerances, material callout, edge chamfer/fillet note Optional: one “generic” drawing with a diameter parameter if that’s more efficient Manufacturing Notes Recommended cutting process (laser vs CNC) Suggested sheet thickness (1.5 mm & 2.0 mm) Basic finishing notes (light deburr / edge polish if needed) Optional (Nice to Have) Simple note or sketch showing how these would interface with a typical clamp ring or housing, for future expansion (not a full housing design at this stage). REQUIRED SKILLS Mechanical design experience (flat plastic components) Comfort with parametric modeling (multiple diameters & thicknesses) Familiarity with laser-cut or CNC-cut plastic part design Basic understanding of FDM 3D printing constraints (for the PETG option)