FreeCAD Automation

When to Use

• CAD automation and scripting
• Batch processing of FreeCAD files
• Parametric design and design tables
• Assembly management and constraint solving
• FEM preprocessing and mesh generation (CalculiX / gmsh)
• Drawing generation with automatic dimensioning
• Marine engineering hull design and hydrostatics
• NURBS hull generation from HullProfile stations
• CalculiX FEM structural analysis
• STEP import / volume mesh / INP export pipeline
• Design table batch parametric studies
• Natural language CAD commands
• Integration with OrcaFlex/AQWA workflows

Prerequisites

• Python 3.8+
• FreeCAD 1.0+ (November 2024 release)
• digitalmodel package installed

Python API

Basic Operations

from digitalmodel.agents.freecad import FreeCADAgent

agent = FreeCADAgent()
result = agent.execute_prompt("Create a box 100x50x25mm with chamfered edges")
print(f"Created: {result['object_name']}")
print(f"Volume: {result['properties']['volume']} mm3")

Batch Processing

results = agent.batch_process(
    pattern="*.FCStd",
    input_directory="./models",
    operation="export_step",
    parallel_workers=4
)

See sub-skills for full details.

Parametric Design

agent.parametric_study(
    base_model="hull_template.FCStd",
    parameters={
        "length": [150, 175, 200, 225],
        "beam": [25, 30, 35],
        "draft": [10, 12, 15]
    },
    output_directory="hull_variations/",
    export_formats=["STEP", "STL"]
)

Hull Generation + Hydrostatics

from digitalmodel.hydrodynamics.hull_library.profile_schema import (
    HullProfile, HullStation, HullType
)
from digitalmodel.visualization.design_tools.freecad_hull import FreeCADHullGenerator
from digitalmodel.visualization.design_tools.hull_hydrostatics import HullHydrostatics

See sub-skills for full details.

FEM Analysis Chain (CalculiX)

from digitalmodel.solvers.calculix import FEMChain, INPWriter

chain = FEMChain(work_dir=Path("/tmp/fem"))
result = chain.run_plate_validation(sigma_applied=100.0)
# result['kt'] ~ 3.0 within 5%

See sub-skills for full details.

STEP Import / Mesh / INP Export

from digitalmodel.solvers.gmsh_meshing import GMSHMeshGenerator

with GMSHMeshGenerator() as gen:
    mesh = gen.generate_mesh_from_step("hull.step", element_size=0.5)
    gen.export_mesh_inp("hull.inp", title="Hull FEM model")

Related Skills

• gmsh-meshing - Advanced mesh generation
• cad-engineering - General CAD expertise
• blender-interface - 3D visualization
• orcaflex/modeling - Hydrodynamic analysis

References

• FreeCAD Documentation: https://wiki.freecad.org/
• FreeCAD Python API: https://wiki.freecad.org/Python_scripting_tutorial

Version History

• 2.0.0 (2026-03-16): Hull NURBS generation, hydrostatics, CalculiX FEM, STEP/INP pipeline, design tables (WRK-1251)
• 1.1.0 (2026-02-24): Output parsing, failure diagnosis, validation (WRK-372)
• 1.0.0 (2025-01-02): Initial release

Sub-Skills

• Agent Settings (+1)
• Version Metadata
• [2.0.0] - 2026-03-16 (+1)
• Core Capabilities (+4)
• Command Line Interface
• Batch Processing Patterns
• Output Formats
• Swarm Coordination (+1)
• Performance Metrics
• FreeCAD Import Error (+1)
• Extract Geometry Properties (+2)
• Common Failures (+2)
• Geometry Validation Checks (+1)
• Parametric Hull Workflow
• FEM Chain Workflow
• Design Table Studies