CadQuery Builder¶

The CadQuery rendering engine. Contains all shape classes, bobbin/winding builders, and export logic.

Module Overview¶

OpenMagneticsVirtualBuilder.cadquery_builder ¶

CadQuery rendering engine for OpenMagneticsVirtualBuilder.

Implements all 21 core shape families, bobbin, and winding geometry using the CadQuery Python CAD scripting library. This engine requires no system CAD installation and is suitable for headless / CI environments.

Shape classes are nested inside :class:CadQueryBuilder and follow the EN 60205 naming convention.

Main Builder Class¶

OpenMagneticsVirtualBuilder.cadquery_builder.CadQueryBuilder ¶

Bases: BuilderBase

Builder for 3D magnetic component geometry using CadQuery.

This class creates 3D geometry for magnetic components including: - Core shapes (E, ETD, PQ, RM, toroidal, etc.) - Coil turns (concentric and toroidal winding styles) - Bobbins

Coordinate System (MAS to CadQuery mapping): - For concentric cores (E, PQ, RM, etc.): - X axis: Core depth direction (perpendicular to winding window) - Y axis: Core width direction (radial, distance from central column) - Z axis: Core height direction (along core axis, vertical) - MAS coordinates[0] (radial) -> Y position - MAS coordinates[1] (height) -> Z position

For toroidal cores:
- Y axis: Core axis (toroid revolves around Y)
- X axis: Radial direction (negative X = inside the donut hole)
- Z axis: Tangential direction (along circumference at Y=0)
- MAS coordinates[0] (radial) -> distance from Y axis
- MAS coordinates[1] (angular) -> rotation angle around Y axis

Units: - All MAS input values are in meters - Internal geometry is built in millimeters for precision - Output is scaled back to meters before export

get_magnetic_assembly ¶

get_magnetic_assembly(project_name, assembly_data, output_path=None, save_files=True, export_files=True)

Build a magnetic assembly from core, bobbin, and winding data.

Parameters¶

project_name : str Name for the output files. assembly_data : dict Dictionary with optional keys: 'core', 'bobbin', 'windings', 'coil'. output_path : str Directory for output files. save_files : bool Whether to save intermediate files. export_files : bool Whether to export STEP/STL files.

get_svg_drawings ¶

get_svg_drawings(project_name, geometrical_description, planes=None, view_types=None, colors=None, output_path=None, save_files=True, slice_offsets=None)

Generate annotated SVG drawings for a core shape.

Parameters:

Name	Description	Default
`project_name`	Name for output files.	required
`geometrical_description`	List of geometrical part descriptions.	required
`planes`	List of ViewPlane values (default: all three).	`None`
`view_types`	List of ViewType values (default: PROJECTION only).	`None`
`colors`	Dict with 'projection_color' and 'dimension_color'.	`None`
`output_path`	Directory for output files.	`None`
`save_files`	Whether to write SVG files to disk.	`True`
`slice_offsets`	Optional dict overriding per-plane slice offsets.	`None`

Returns:

Type	Description
	Dict of {key: svg_string} where key is e.g. 'xy_projection'.

get_dxf_drawings ¶

get_dxf_drawings(project_name, geometrical_description, planes=None, view_types=None, colors=None, output_path=None, slice_offsets=None)

Generate DXF drawings for a core shape.

Returns:

Type	Description
	Dict of {key: filepath} where key is e.g. 'xy_projection'.

get_fcstd_sketches ¶

get_fcstd_sketches(project_name, geometrical_description, planes=None, view_types=None, output_path=None, slice_offsets=None)

Generate FreeCAD macro files (.FCMacro) for a core shape.

Returns:

Type	Description
	Dict of {key: filepath} where key is e.g. 'xy_projection'.

get_assembly_svg_drawings ¶

get_assembly_svg_drawings(project_name, magnetic_data, planes=None, view_types=None, colors=None, output_path=None, save_files=True, slice_offsets=None, components=None)

Generate annotated SVG drawings for an assembly or individual components.

Parameters:

Name	Description	Default
`project_name`	Name for output files.	required
`magnetic_data`	MAS magnetic data dict.	required
`planes`	List of ViewPlane values.	`None`
`view_types`	List of ViewType values.	`None`
`colors`	Color config dict.	`None`
`output_path`	Directory for output files.	`None`
`save_files`	Whether to write SVG files to disk.	`True`
`slice_offsets`	Optional per-plane slice offsets.	`None`
`components`	List of components to draw: 'assembly', 'core', 'bobbin', 'winding'. Default is ['assembly'].	`None`

Returns:

Type	Description
	Dict of {component_key: svg_string}.

get_assembly_dxf_drawings ¶

get_assembly_dxf_drawings(project_name, magnetic_data, planes=None, view_types=None, colors=None, output_path=None, slice_offsets=None, components=None)

Generate DXF drawings for assembly or individual components.

Returns:

Type	Description
	Dict of {component_key: filepath}.

get_assembly_fcstd_sketches ¶

get_assembly_fcstd_sketches(project_name, magnetic_data, planes=None, view_types=None, output_path=None, slice_offsets=None, components=None)

Generate FreeCAD macro files for assembly or individual components.

Returns:

Type	Description
	Dict of {component_key: filepath}.

get_turn ¶

get_turn(turn_description: TurnDescription, wire_description: WireDescription, bobbin_description: BobbinProcessedDescription, is_toroidal: bool = False) -> cq.Workplane

Create a single turn geometry.

Parameters:

Name	Type	Description	Default
`turn_description`	`TurnDescription`	Turn parameters (coordinates, winding, etc.)	required
`wire_description`	`WireDescription`	Wire parameters (type, diameter, etc.)	required
`bobbin_description`	`BobbinProcessedDescription`	Bobbin parameters	required
`is_toroidal`	`bool`	If True, create toroidal turn; otherwise concentric turn	`False`

Returns:

Type	Description
`Workplane`	CadQuery Workplane with the turn geometry

get_magnetic ¶

get_magnetic(magnetic_data: dict, project_name: str = 'Magnetic', output_path: str = None, export_files: bool = True)

Build complete magnetic assembly (core + coil).

Parameters:

Name	Type	Description	Default
`magnetic_data`	`dict`	MAS format magnetic data with 'core' and 'coil' keys	required
`project_name`	`str`	Name for the output files	`'Magnetic'`
`output_path`	`str`	Directory for output files	`None`
`export_files`	`bool`	Whether to export STEP/STL files	`True`

Returns:

Type	Description
	Tuple of (step_path, stl_path) or compound if export_files is False

Enums¶

OpenMagneticsVirtualBuilder.cadquery_builder.WireType ¶

Bases: Enum

Wire types supported.

OpenMagneticsVirtualBuilder.cadquery_builder.ColumnShape ¶

Bases: Enum

Bobbin column shapes.

Data Classes¶

OpenMagneticsVirtualBuilder.cadquery_builder.WireDescription `dataclass` ¶

Description of a wire.

OpenMagneticsVirtualBuilder.cadquery_builder.TurnDescription `dataclass` ¶

Description of a single turn.

OpenMagneticsVirtualBuilder.cadquery_builder.BobbinProcessedDescription `dataclass` ¶

Processed bobbin description.

Utility Functions¶

OpenMagneticsVirtualBuilder.cadquery_builder.set_tessellation_quality ¶

set_tessellation_quality(segments_per_circle: int = 20, linear_tolerance: float = 0.1)

Configure the tessellation quality for STL export.

Parameters:

Name	Type	Description	Default
`segments_per_circle`	`int`	Number of segments per full circle (default: 20). - 8-12: Very coarse, good for previews - 16-24: Medium quality, good balance - 32-48: High quality, smooth curves - 64+: Very high quality, large files	`20`
`linear_tolerance`	`float`	Maximum chord deviation in mm (default: 0.1). Smaller values = more accurate but more polygons.	`0.1`

Example

Coarse quality for fast previews¶

set_tessellation_quality(segments_per_circle=12)

High quality for final renders¶

set_tessellation_quality(segments_per_circle=48, linear_tolerance=0.01)

Source code in src/OpenMagneticsVirtualBuilder/cadquery_builder.py

def set_tessellation_quality(segments_per_circle: int = 20, linear_tolerance: float = 0.1):
    """Configure the tessellation quality for STL export.

    Args:
        segments_per_circle: Number of segments per full circle (default: 20).
            - 8-12: Very coarse, good for previews
            - 16-24: Medium quality, good balance
            - 32-48: High quality, smooth curves
            - 64+: Very high quality, large files
        linear_tolerance: Maximum chord deviation in mm (default: 0.1).
            Smaller values = more accurate but more polygons.

    Example:
        # Coarse quality for fast previews
        set_tessellation_quality(segments_per_circle=12)

        # High quality for final renders
        set_tessellation_quality(segments_per_circle=48, linear_tolerance=0.01)
    """
    global TESSELLATION_SEGMENTS_PER_CIRCLE, TESSELLATION_LINEAR_TOLERANCE
    TESSELLATION_SEGMENTS_PER_CIRCLE = segments_per_circle
    TESSELLATION_LINEAR_TOLERANCE = linear_tolerance

OpenMagneticsVirtualBuilder.cadquery_builder.resolve_dimensional_value ¶

resolve_dimensional_value(value: Any) -> float

Extract numeric value from dimensional data (handles dict with 'nominal' or plain value).

Source code in src/OpenMagneticsVirtualBuilder/cadquery_builder.py

def resolve_dimensional_value(value: Any) -> float:
    """Extract numeric value from dimensional data (handles dict with 'nominal' or plain value)."""
    if value is None:
        return 0.0
    if isinstance(value, dict):
        return value.get("nominal", value.get("minimum", value.get("maximum", 0.0)))
    return float(value)

CadQuery Builder¶

Module Overview¶

OpenMagneticsVirtualBuilder.cadquery_builder ¶

Main Builder Class¶

OpenMagneticsVirtualBuilder.cadquery_builder.CadQueryBuilder ¶

get_magnetic_assembly ¶

Parameters¶

get_svg_drawings ¶

get_dxf_drawings ¶

get_fcstd_sketches ¶

get_assembly_svg_drawings ¶

get_assembly_dxf_drawings ¶

get_assembly_fcstd_sketches ¶

get_turn ¶

get_magnetic ¶

Enums¶

OpenMagneticsVirtualBuilder.cadquery_builder.WireType ¶

OpenMagneticsVirtualBuilder.cadquery_builder.ColumnShape ¶

Data Classes¶

OpenMagneticsVirtualBuilder.cadquery_builder.WireDescription dataclass ¶

OpenMagneticsVirtualBuilder.cadquery_builder.TurnDescription dataclass ¶

OpenMagneticsVirtualBuilder.cadquery_builder.BobbinProcessedDescription dataclass ¶

Utility Functions¶

OpenMagneticsVirtualBuilder.cadquery_builder.set_tessellation_quality ¶

Coarse quality for fast previews¶

High quality for final renders¶

OpenMagneticsVirtualBuilder.cadquery_builder.resolve_dimensional_value ¶

OpenMagneticsVirtualBuilder.cadquery_builder.WireDescription `dataclass` ¶

OpenMagneticsVirtualBuilder.cadquery_builder.TurnDescription `dataclass` ¶

OpenMagneticsVirtualBuilder.cadquery_builder.BobbinProcessedDescription `dataclass` ¶