Developed by Robot Dolphins from Outer Space: Team 5199 & Gemini Pro

A robust OpenSCAD toolkit for generating large-scale ChArUco calibration boards that can be split and 3D printed on standard-sized beds. This project features precision multi-material slicing support and modular assembly options, making it easy to create professional-grade computer vision calibration targets without a large-format printer.

Figure 1: The parametric model rendered in OpenSCAD, showing the modular split and alignment features.

For convenience, we have provided ready-to-print files for a standard 15x15 Grid configuration:

• STL Models (stl/): Contains exported "White Base" and "Black Pattern" files pre-configured for:
  • Prusa XL
  • Bambu Labs X1E
• Slicer Projects (slicer/): Contains pre-configured project files (with multi-material settings applied) for:
  • Prusa Slicer (for Prusa XL)
  • Bambu Studio (for Bambu Labs X1E)

• Auto-Splitting: Automatically slices large targets (e.g., 15x15 grids) into printable sections compatible with standard build volumes like the Prusa XL, Bambu X1, and Prusa MK4.
• Modular Assembly: Choose between two robust connection styles:
  • Smart Dovetails: Precision puzzle-fit with anchored geometry for a flat, glue-assembled board.
  • Joiner Plates: Reinforced screw-fastened connections using printed plates and standard M3/wood screws. (⚠️ Note: This connection style is currently in development and untested.)
• Multi-Material Ready: Generates separate "White Base" and "Black Pattern" STL files with anchored geometry, ensuring perfect boolean unions in slicers.
• Robust Geometry: Includes reinforcement bosses for screw holes and "top-open" dovetail slots to ensure easy assembly and structural integrity.
• Python Integration: Includes a helper script to generate standard ArUco dictionary patterns (markers.scad).

1. Generate Markers: Run the included Python script to generate the ArUco marker library:

   python generate_library.py

2. Configure: Open the .scad file in OpenSCAD and select your Printer Model and Connection Type in the Customizer.
   • Note: Extensive usage information, advanced configuration options, and logic explanations are provided as inline comments within the SCAD source file.
3. Export: Select the Part Index you wish to print, then export the White Base and Black Pattern files separately.
4. Print: Import both files into your slicer as a "Multi-Part Object" to preserve alignment and assign filament colors.

Figure 2: The generated parts imported into the slicer as a single multi-material object, ready for printing.