Cad Operations

CAD Operations

Purpose

Use this as a single entry point for CAD work. Route each task to the narrowest reproducible workflow, prefer generated/interchange files before manual edits, and verify outputs with live files or rendered previews before delivery.

First decisions

1. Identify the CAD family

   • Electrical main wiring / SLD / 变电站主接线 / 一次接线图 → read references/electrical-main-sld.md, use scripts/make_main_sld.py.
   • Pavement / road layer cross-section / 路面结构图 → read references/pavement-structure-cad.md, use scripts/generate_pavement_cad_ezdxf.py.
   • SolidWorks parts, assemblies, drawings, STEP/STL/SLDPRT/SLDASM, feature creation, mates, rebuilds → read references/solidworks-mcp.md.
   • Generic 2D DWG/DXF editing, plotting, conversion, or AutoCAD/FreeCAD use → read references/autocad-freecad.md.
   • Unsure or environment-sensitive → read references/local-cad-environment.md.

2. Choose the output source of truth

   • Prefer DXF for editable 2D CAD interchange.
   • Prefer SLDPRT/SLDASM/SLDDRW for native SolidWorks work, then export STEP/STL/DXF/PDF as requested.
   • Use PDF/SVG/PNG previews for review; do not rely on DXF syntax alone for layout correctness.
   • DWG is proprietary: generate/modify DXF first, then convert or save as DWG through AutoCAD/ODA/LibreCAD/SolidWorks when explicitly required.

3. Keep work reproducible

   • Create specs/scripts in the active workspace, not in the skill directory.
   • Keep originals separate from generated files.
   • Prefer editing a JSON spec or script and regenerating rather than hand-patching many coordinates.
   • For destructive edits to native CAD files, save a copy/backup first unless the user explicitly requests in-place modification.

Quick commands

Electrical SLD:

python scripts/make_main_sld.py examples/electrical_sld_spec.json --outdir output/sld --stem main_sld

Pavement structure DXF:

python scripts/generate_pavement_cad_ezdxf.py examples/pavement_structure_spec.json --out output/pavement

Open a generated CAD file in AutoCAD when configured:

& $env:AUTOCAD_EXE "output\pavement\pavement_structure.dxf"

Start a local SolidWorks MCP server for diagnostics when installed:

Set-Location -LiteralPath $env:SOLIDWORKS_MCP_HOME
& ".\.venv\Scripts\python.exe" -m solidworks_mcp.server

Verification rules

Before final response on any CAD deliverable:

• Confirm every requested output file exists and is non-empty.
• For DXF, validate with ezdxf.readfile when possible.
• For PDF/SVG/PNG, render or inspect the latest preview when visual layout matters.
• For SolidWorks, require live rebuild/status evidence plus saved native/export files; mock-mode MCP results are not engineering truth.
• Report exact paths and any assumptions about units, dimensions, standards, topology, or missing source data.

Bundled resources

• scripts/make_main_sld.py — parameterized electrical main single-line diagram generator; outputs DXF/PDF/SVG.
• scripts/generate_pavement_cad_ezdxf.py — lightweight pavement structure DXF generator using ezdxf.
• scripts/generate_pavement_cad.py — dependency-light fallback pavement CAD generator.
• scripts/audit_sld.py — generic DXF audit helper for generated SLD drawings.
• references/local-cad-environment.md — environment variables, tool discovery, and MCP status checks.
• references/electrical-main-sld.md — SLD workflow, symbols, topology, checks.
• references/pavement-structure-cad.md — pavement JSON schema and workflow.
• references/solidworks-mcp.md — SolidWorks MCP, COM/VBA fallback, verification.
• references/autocad-freecad.md — AutoCAD/Core Console and FreeCAD notes.