How to Chamfer Specific Edges in FreeCAD

Applying a chamfer to specific edges of a FreeCAD model is a straightforward process primarily handled within the Part Design Workbench. This guide walks you through selecting targeted edges, activating the chamfer tool, adjusting dimensional parameters, and troubleshooting edge selection using FreeCAD's parametric task panel.

Step 1: Open the Part Design Workbench

  1. Ensure your 3D model is active inside a Body container within the Part Design Workbench.
  2. If your model was built using the Part Workbench, switch to the Part Workbench instead, as the workflow is nearly identical but relies on the Part Chamfer tool.

Step 2: Select the Specific Edges

  1. In the 3D viewport, click directly on the edge you want to beveled. The edge will turn green (or your system's highlight color) when selected.
  2. To select multiple specific edges, hold down the Ctrl key (or Cmd on macOS) while clicking each additional edge.
  3. Avoid clicking entire faces unless you intend to chamfer every boundary edge of that face.

Step 3: Activate the Chamfer Tool

  1. With the edges selected, click the Chamfer icon in the toolbar (represented by a cube with a beveled edge) or navigate to Part Design > Apply a dress-up feature > Chamfer from the top menu.
  2. A Chamfer task panel will appear in the Tasks tab on the left side of the screen, and a preview will display in the 3D view.

Step 4: Adjust Edge Selections in the Task Panel

If you need to modify your selection while the tool is open:

  • Click the Add button in the task panel, then click any additional edges in the 3D view to include them.
  • Click the Remove button, then click an active edge in the 3D view to exclude it from the operation.

Step 5: Configure Chamfer Parameters

Choose your chamfer type and dimensions in the task panel:

  • Equal distance: Applies a uniform 45-degree cut using a single specified size.
  • Two distances: Allows distinct bevel depths along the two adjacent faces.
  • Distance and Angle: Sets a primary depth along one face and an angle (e.g., 30° or 60°) relative to it.

Step 6: Complete the Operation

  1. Enter your desired dimension in the Size field. Ensure the size does not exceed the dimensions of adjacent geometry, which causes the operation to fail.
  2. Click OK to apply the chamfer. The feature will appear as a Chamfer object under your active Body in the tree view.

Troubleshooting

  • Failed to create chamfer: If the operation returns an error, reduce the chamfer size. Large chamfers often self-intersect or consume adjacent features entirely.
  • Selection issues: If you cannot select edges individually, ensure the model's display mode is set to Shaded or As Is with wireframe visibility turned on (press V then 3 on your keyboard).