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Scale

In one sentence: Rescale the selected mesh by a numeric factor to correct unit errors or resize the model.

Overview

Workbench: Mesh
Menu: Mesh → Meshes → Scale…
Command: Mesh_Scale
Shortcut: none

Scales the selected mesh by a uniform numeric factor. The scale is applied directly to the vertex coordinates — it is not a parametric operation.

Intuition

The most common use case is correcting a unit mismatch: an STL exported in inches will appear 25.4× too small in FreeCAD (which uses millimetres). Scale by 25.4 to bring it to the correct size. Verify the result with Bounding Box.

When to use it

  • An imported STL is the wrong size because it was exported in inches.
  • You need to uniformly resize a mesh (e.g., scale up by 2×).

When NOT to use it

  • Don't use it for non-uniform scaling — this tool applies one factor to all three axes. For per-axis scaling, use the Python API or an external tool.
  • Don't use it on parametric geometry — use the dimensional parameters of Part/PartDesign features instead.

Step-by-step

  1. Select the mesh.
  2. Choose Mesh → Meshes → Scale….
  3. Enter the scale factor (e.g. 25.4 for inches to mm).
  4. Click OK.
  5. Verify the new dimensions with Bounding Box.

Common mistakes and pitfalls

Scale is not parametric

Scale modifies the mesh in place without a history entry. Use Ctrl+Z to undo if the wrong factor was applied.

Re-check the bounding box after scaling

Always verify the bounding box dimensions after scaling to confirm the result matches the expected physical dimensions.

Python API

import FreeCAD as App

mesh_obj = App.ActiveDocument.getObject("Mesh")
msh = mesh_obj.Mesh.copy()
msh.scale(25.4)   # inches to mm
mesh_obj.Mesh = msh
App.ActiveDocument.recompute()

See also