How to Create a Draft Angle in FreeCAD Part Design

Adding a draft angle to extruded walls is an essential modeling step for designing parts intended for injection molding, casting, or 3D printing with overhangs. In the FreeCAD Part Design workbench, you can apply draft angles either directly during the extrusion process using the Pad tool's taper setting or after the fact using the dedicated Draft feature. This guide explains both methods step-by-step so you can easily taper vertical walls in your solid models.

Method 1: Using the Built-In Taper Setting in the Pad Tool

The quickest way to draft extruded walls is directly within the initial Pad command.

  1. Open your model in the Part Design workbench.
  2. Create and constrain a sketch on your desired plane.
  3. With the sketch selected, click the Pad tool.
  4. In the Pad parameters panel on the left (Tasks tab), locate the Taper angle field.
  5. Enter your desired draft angle in degrees:
    • A positive value widens the extrusion outward as it grows.
    • A negative value tapers the extrusion inward.
  6. Set the extrusion length and click OK to apply the draft.

Method 2: Using the Dedicated Draft Tool

If your extrusion has already been created, or if you only need to draft specific faces rather than the entire perimeter, use the Part Design Draft tool.

Step 1: Select the Faces to Draft

Click to select the vertical wall face (or hold Ctrl and click multiple faces) that requires tapering.

Step 2: Activate the Draft Feature

Click the Draft icon in the Part Design toolbar (represented by a yellow tapered cylinder or block), or go to Part Design > Apply a dress-up feature > Draft.

Step 3: Set the Neutral Plane

The neutral plane defines the reference plane where the dimensions of the part will not change when the draft is applied:

  1. In the Draft task panel, click the Neutral plane button.
  2. In the 3D view, select the base face from which the draft should hinge (typically the bottom face or top face of the extrusion).

Step 4: Define Pull Direction and Angle

  1. Set the Draft angle value (e.g., 1.5° to 3° for standard injection molding).
  2. If the taper is slanting inward instead of outward, check or uncheck the Reverse pull direction box.
  3. If the draft angle is not moving in the expected axis, click Pull direction and select a reference edge or datum line aligned with your mold draw direction.

Step 5: Finalize the Feature

Click OK in the Tasks panel. The Draft feature will be added to your model tree, and the selected walls will now be tapered.

Best Practices for Draft Angles in FreeCAD

  • Feature Order: Always apply drafts before adding edge dress-up features such as fillets and chamfers. Applying fillets before a draft often causes the draft operation to fail or break geometric continuity.
  • Complex Profiles: If the dedicated Draft tool fails on complex geometries with tangent arcs, use Method 1 (Pad Taper angle) or create the taper manually using a Loft or a Groove/Pocket with a drafted sketch.