FreeCAD: Create a Polar Pattern in Sketcher

This guide explains how to duplicate and arrange 2D geometric elements in a circular array directly inside the FreeCAD Sketcher workbench. Creating a polar pattern within a sketch allows you to design radially symmetrical geometry—such as bolt circles, slots, or spoke layouts—before extruding or pocketing your 3D model.

Prerequisites

Ensure you are in the Sketcher Workbench or inside an active sketch within the Part Design Workbench. The elements you want to repeat must already be drawn.

Step 1: Select the Geometry

  1. Open your sketch in edit mode.
  2. Select all the geometry (lines, arcs, circles, or constraints) that you want to include in the circular pattern. You can box-select multiple items or hold Ctrl while clicking each element.

Step 2: Launch the Polar Pattern Tool

  1. Locate the Polar Pattern tool in the Sketcher toolbar. Depending on your FreeCAD version:
    • In FreeCAD 0.21 and later: Look for the Create a polar pattern icon (or find it nested under the Array / Clone dropdown menu).
    • Via the top menu: Navigate to Sketch > Sketcher tools > Polar pattern.
  2. Click the tool icon to open the configuration dialog or activate the cursor prompt.

Step 3: Define the Center of Rotation

  1. Click on the point in your sketch that will serve as the center of rotation (such as the sketch origin or a custom construction point).
  2. If the tool automatically defaults to the sketch origin, you can adjust the center coordinates manually in the parameters window.

Step 4: Configure the Pattern Parameters

In the dialog box that appears:

  • Count / Copies: Enter the total number of instances you want, including the original element.
  • Angle: Specify the total span for the pattern (use 360° for a complete circle, or a smaller angle such as 180° for a semi-circular spread).
  • Apply Dimensional Constraints: Check this option if you want FreeCAD to automatically apply angle and distance constraints to the patterned elements to keep the sketch fully constrained.

Step 5: Finalize and Validate

  1. Click OK to generate the polar pattern.
  2. Review the resulting elements. If needed, apply any missing geometric or dimensional constraints to eliminate remaining degrees of freedom.
  3. Close the sketch to proceed with 3D operations like Pad or Pocket.