How to Create a Polygon in FreeCAD Sketcher

Creating a polygon with a custom number of sides in FreeCAD is a straightforward process handled directly within the Sketcher workbench. By utilizing the dedicated regular polygon tool, you can define any geometric shape ranging from standard triangles and hexagons to complex multi-sided figures. This guide covers how to access the tool, specify your exact side count, place the geometry, and properly constrain the finished polygon.

1. Open the Sketcher Workbench

To begin, create a new document and open an existing sketch, or create a new one using the Part Design or Sketcher workbench. Ensure you are in the active sketch editing mode with the 2D grid visible.

2. Select the Regular Polygon Tool

Locate the polygon creation options on the Sketcher geometry toolbar:

  1. Find the Hexagon icon or the regular polygon dropdown menu.
  2. Click the small arrow next to the icon to open the polygon options.
  3. Select the generic Regular polygon tool (often represented by a polygon icon or labeled "Create regular polygon").

3. Specify the Number of Sides

Once you select the tool, FreeCAD will prompt you to define the shape:

  1. A small dialog box will appear asking for the Number of sides.
  2. Enter the exact number of sides you require (any integer from 3 upwards).
  3. Click OK to confirm your selection.

4. Place and Scale the Polygon

With the number of sides set, place the shape in your sketch:

  1. Click once in the 3D view to set the center point of the polygon.
  2. Drag your cursor away from the center to set the overall size and orientation.
  3. Click a second time to finalize the initial placement.

5. Constrain the Polygon Dimensions

FreeCAD automatically generates the polygon bounded by an internal construction circle (indicated by blue dashed lines) along with symmetry constraints. To fully constrain the polygon:

  • Size: Apply a radius constraint to the internal construction circle, or select one of the perimeter edges and apply a horizontal, vertical, or length constraint.
  • Orientation: Select one of the outer edges or one of the construction lines running to a vertex, and apply a horizontal or vertical constraint to lock rotation.
  • Position: Constrain the center point to the sketch origin or to existing reference geometry.