From FreeCAD Documentation
- To add edges do one of the following:
- Press the Add button to start selecting edges and/or faces in the 3D view.
- To select all remaining edges do the following:
- If required press the Add button.
- Use the Ctrl+Shift+A keyboard shortcut, or right-click the list and select Add all edges from the context menu. introduced in version 0.20
- To remove edges do one of the following:
- Press the Remove button to start deselecting edges and/or faces in the 3D view. Selected elements are highlighted in purple.
- Select one or more elements in the list and press the Del key, or right-click the list and select Remove from the context menu.
- Specify a chamfer Type:
- Equal distance: One distance is used to place both chamfer edges.
- Two distances: Two distances are used to place the chamfer edges.
- Distance and angle: A distance is used to place one chamfer edge, the placement of the other chamfer edge is defined by the angle of the chamfer.
- Press the
Flip direction button to flip the direction of the chamfer (deactivated for Equal distance).
- Set the Size of the chamfer.
- Set the Size2 of the chamfer (only available if Two distances is selected).
- Set the Angle of the chamfer (only available if Distance and angle is selected).
- Check the Use all edges checkbox to select all edges of the previous feature. This deactivates the selection list and the related buttons. introduced in version 0.20