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OpenMagnetics Virtual Builder

  • Generate 3D Models

    Create parametric STEP, STL, and OBJ files for 21 magnetic core shape families from MAS schema data.

  • Technical Drawings

    Produce annotated SVG, DXF, and FreeCAD macro 2D drawings with dimension lines and gapping details.

  • Dual CAD Engines

    Choose between CadQuery (pure Python, no system dependencies) and FreeCAD (full CAD functionality).

  • Complete Assemblies

    Build full magnetic components including cores, bobbins, coils, and windings.

PyPI License GitHub

What is MVB?

Magnetics Virtual Builder (MVB) generates FreeCAD and CadQuery based files from any magnetic component defined following the MAS (Magnetic Assembly Schema) standard. Output includes:

  • 3D models: .step, .stl, .obj files
  • 2D technical drawings: .svg, .dxf, .FCMacro files
  • Meshes for simulation

Quick Example

from OpenMagneticsVirtualBuilder.builder import Builder

# Create a builder with the CadQuery engine (default)
builder = Builder("CadQuery")

# List all available core shape families
families = builder.get_families()
print(list(families.keys()))
# ['etd', 'er', 'ep', 'epx', 'pq', 'e', 'pm', 'p', 'rm', ...]

Supported Shape Families

Family Shapes Description
E Family E, ETD, ER, EFD, EC, EQ, EP, EPX E-shaped cores and variants
P Family P, PQ, PM, RM Pot cores and variants
Planar PLANAR_E, PLANAR_ER, PLANAR_EL, LP Low-profile planar cores
U Family U, UR, UT U-shaped cores
Toroidal T Ring / toroidal cores
C Cores C C-shaped cut cores

Next Steps