How to Create Dimensions in FreeCAD Draft Workbench

This guide explains how to create linear, radial, and angular dimension lines in FreeCAD using the Draft workbench. You will learn how to set up the working plane, snap to geometry, insert dimension lines accurately, and customize their visual properties like text size, arrows, and units for clear technical drawings.

Step 1: Switch to the Draft Workbench

  1. Open your model or drawing in FreeCAD.
  2. Click on the workbench selector dropdown in the top toolbar.
  3. Select Draft.

Step 2: Set the Working Plane

Draft dimensions are projected onto the active working plane. Ensuring the plane is aligned correctly prevents misplaced annotations:

  1. Locate the Draft working plane button on the Draft toolbar (it usually displays Auto, Top, Front, or Side).
  2. Set it to the plane matching your geometry (e.g., Top (XY) for top-down 2D sketches).
  3. Alternatively, select a flat face on your 3D model and click the working plane button to align the plane directly to that face.

Step 3: Configure Snapping

Accurate dimensions require snapping to exact vertices or edges:

  1. Ensure the Draft Snap toolbar is visible (enabled via View > Toolbars > Draft snap).
  2. Activate Snap End, Snap Midpoint, or Snap Intersection depending on the points you need to measure.

Step 4: Create a Linear Dimension

To measure the distance between two points:

  1. Click the Dimension tool icon in the Draft toolbar, or use the keyboard shortcut D followed by I, or navigate to Draft > Annotation > Dimension.
  2. Click the first point on your geometry.
  3. Click the second point on your geometry.
  4. Move your mouse away from the geometry to define the offset distance of the dimension line.
  5. Click a third time to place the dimension line and text.

Alternative method for single edges: Select a straight edge first, then click the Dimension tool, and click once more in the 3D view to place the dimension.

Step 5: Create Radial, Diametrical, or Angular Dimensions

The same Dimension tool handles curves and angles based on pre-selection:

  • Radius or Diameter: Select a circular edge or arc, click the Dimension tool, and click in the viewport to position the annotation.
  • Angle: Select two non-parallel straight edges while holding Ctrl, click the Dimension tool, and click to set the angular dimension arc position.

Step 6: Customize Dimension Properties

Once a dimension is placed, you can adjust its appearance and formatting:

  1. Select the dimension object in the Tree view.
  2. In the Property panel at the bottom-left:
    • View Tab: Modify visual settings such as Font Size, Arrow Type, Arrow Size, Line Color, and Decimals.
    • Data Tab: Modify geometric parameters, change the display mode between standard/diameter, or enter custom text in the Override field to replace the measured value with custom annotations.