Free online FCSTD to PLY converter

What the FCSTD format is

.FCStd is FreeCAD's native document format. It can store parametric parts, sketches, bodies, assemblies, constraints, feature history, and document metadata rather than only a surface mesh. FreeCAD creates FCSTD files, and they commonly appear in mechanical design, CAD, engineering, and 3D-printing workflows.

What the PLY format is

.PLY, also called Polygon File Format or Stanford Triangle Format, stores vertices and polygon faces. It is used by mesh viewers, 3D-scanning software, photogrammetry tools, point-cloud applications, and graphics programs. PLY can store vertex colors, normals, and other properties, but it does not preserve FreeCAD feature history, sketches, constraints, or editable parametric relationships.

How to convert FCSTD to PLY

Using FreeCAD

1. Open the .FCStd file in FreeCAD.
2. Make the required solid or bodies visible in the Model tree. Hide construction geometry, sketches, and objects that should not appear in the mesh.
3. Select the solid, Part, Body, or compound to export.
4. Switch to the Mesh Design workbench and choose Meshes → Create mesh from shape. Set the mesh deviation or linear deflection and angular deflection. Smaller values create more triangles and preserve curved surfaces more accurately.
5. Select the generated mesh object and choose File → Export.
6. Enter a filename ending in .ply, select the PLY format if FreeCAD displays a format list, and save the file.

For several separate objects, create a mesh for each one and export them separately, or combine them into a compound before meshing if the receiving application requires one PLY object.

Using the FreeCAD Python console

FreeCAD can generate the mesh and write PLY directly. Replace Part with the internal name of the object being exported:

import FreeCAD as App
import MeshPart

doc = App.openDocument("input.FCStd")
obj = doc.getObject("Part")
mesh = MeshPart.meshFromShape(
    Shape=obj.Shape,
    LinearDeflection=0.1,
    AngularDeflection=0.2,
    Relative=False
)
mesh.write("output.ply")

The deflection values use the document's model units; FreeCAD commonly uses millimetres. Adjust them to control the balance between surface accuracy and file size.

Using 101convert

You can also convert the file on the 101convert website for free without installing software. Check the resulting mesh in a viewer because online conversion may offer fewer controls for tessellation, object selection, and material handling than FreeCAD.

Quality and compatibility considerations

• FCSTD-to-PLY is a CAD-to-mesh conversion. Curved and analytic surfaces are tessellated into triangles, so the PLY file cannot retain exact CAD geometry or feature editability.
• A finer mesh reduces visible faceting but increases triangle count, memory use, and export time. Use a coarse setting for previews and a finer setting for inspection or fabrication.
• PLY has no standard unit declaration. FreeCAD normally exports coordinates in its document units, so confirm whether the receiving program interprets the values as millimetres, centimetres, or metres.
• FreeCAD usually exports geometry reliably, but material colors, transparency, normals, and per-face properties may not transfer consistently between PLY readers. Verify these attributes in the target application.
• Check the exported mesh for holes, inverted normals, duplicate surfaces, and non-manifold edges before using it for 3D printing or simulation.