fabrication_pipeline

Fabrication Pipeline

A repeatable, headless pipeline that takes FreeCAD assembly/part models, analyses and validates them, and produces print-ready, vendor-complete A4 fabrication drawings (PDF) on the RES title-block template using the MusaCAD native .musa format and its real plot pipeline.

Built for and driven by Claude Code: the pipeline stages are exposed as slash commands with an interactive, decision-by-decision finalisation step.

Pipeline

/analyse <model_dir>   headless FreeCAD extraction -> reports/analysis.json
/judge                 fabrication-readiness verdict (report-only)
        ⏸ user approval
/finalise              conversational elicitation -> locked manifests/manifest.json
/draw                  HLR views + sections + GD&T + dims -> output/musa/*.musa
/export                plot to A4 PDFs + merged print set -> output/pdf/
/pipeline <model_dir>  all stages, pausing after /judge

Subagents: model-analyst (FreeCAD interrogation), draftsman (.musa composition), qa-checker (21-point output verification, render-and-inspect).

What the drawings contain

• Per part: front view + full section (or an agreed alternative view), true-value dimensions (geometry authored full-size; the template is scaled uniformly — paper size and aspect ratio are never touched), feature location dims (pitch / edge references / TYP), depth-annotated fit callouts (e.g. 3 X Ø4 H7 (REAM) THRU), GD&T datum flags + feature control frames, ANSI31 section hatch, fabrication notes, a shaded isometric pictorial, and a fully populated RES title block (scale, rev, weight computed from the model, parts row).
• Per assembly: NTS isometric HLR wireframe with circled balloons, parts table and build notes.
• A collision-driven layout engine places every annotation (dimension text modelled to MusaCAD's exact rendering geometry, line bands, extension corridors, leaders, frames, notes) with auto-nudge and a hard zero-overlap gate: a sheet that cannot be laid out cleanly fails loudly.

Requirements

Component	Notes
FreeCAD ≥ 1.1 (AppImage)	path configured in src/common.py; used headlessly (TechDraw.projectEx, Shape.slice, mesh export)
MusaCAD source + release build	tools/musa_plot links against its static libs (see tools/CMakeLists.txt); the MusaCAD tree is never modified
Qt 6, CMake, C++23 compiler	to build tools/musa_plot (tools/build.sh)
poppler-utils	pdfinfo / pdftoppm / pdfunite
Python 3.12 + pyvista/VTK + Pillow	shaded pictorials (offscreen), calibration tooling

Build the plot harness once: tools/build.sh → tools/bin/musa_plot.

Layout

src/          pipeline modules (one per stage + FreeCAD-side scripts)
tools/        musa_plot: headless .musa -> PDF harness (paper, scale,
              window, raster stamps) derived from MusaCAD's plot_check
templates/    RES title-block template (.musa v14)
.claude/      slash commands + subagents (the operator interface)
reports/ manifests/ output/    generated per-project artifacts (gitignored)

CLAUDE.md is the full project memory: toolchain invocations, the .musa v14 grammar notes, the scale model, layout-engine rules, and the drawing style contract.

Using vs. developing

• Using (generating drawings for a project): run the slash commands only; per-project state lives in reports/, manifests/, output/ and is not part of this repository.
• Developing (changing the software): everything under src/, tools/, .claude/, templates/ — keep CLAUDE.md in sync.

License

LGPL-3.0-or-later, matching MusaCAD — see COPYING and COPYING.LESSER. Source files carry SPDX tags. tools/musa_plot.cpp is derived from MusaCAD's tools/plot_check.cpp (LGPL-3.0-or-later) and links against the MusaCAD libraries.

Copyright (C) 2026 Pranay Kiran