How to Use MultiTransform in FreeCAD

This guide explains how to combine multiple geometric transformations in FreeCAD. While FreeCAD features a dedicated MultiTransform tool in the Part Design Workbench to sequentially pattern 3D features derived from sketches, users looking to multiply 2D sketch entities directly must rely on specific Sketcher tools or the Draft Workbench. Below, you will learn how to apply multi-transformations to 3D features created from sketches, as well as how to transform 2D sketch geometry directly.

Method 1: Using the Part Design MultiTransform Tool on Sketched Features

In FreeCAD's Part Design Workbench, the MultiTransform tool cannot be applied directly to an unextruded sketch. Instead, it is applied to a feature generated by a sketch (such as a Pad, Pocket, or Hole).

  1. Create the Base Geometry:
    • Open the Part Design Workbench and create a new Body.
    • Create a base sketch and pad it to create your main solid.
  2. Create the Feature Sketch:
    • Create a second sketch on a face of the solid containing the profile you want to transform (for example, a hole or a slot).
    • Apply a Pad or Pocket feature to that sketch.
  3. Apply MultiTransform:
    • Select the newly created feature (Pad or Pocket) in the Model Tree.
    • Click the Create a MultiTransform feature icon on the toolbar.
  4. Add Transformation Steps:
    • In the Tasks tab, right-click the empty list under Transformations.
    • Add your desired operations in the sequence you want them evaluated:
      • Linear Pattern: Define the direction, spacing, and number of occurrences.
      • Polar Pattern: Choose an axis of rotation, angle, and number of occurrences.
      • Mirrored: Select a reference plane to mirror across.
      • Scaled: Scale the feature up or down (if required).
  5. Finalize:
    • Ensure that the transformations do not generate intersecting or disconnected geometry that violates the single-solid rule.
    • Click OK to compute the final multi-transformed shape.

Method 2: Transforming Entities Directly Inside a Sketch

If you need duplicate geometry inside the 2D sketch itself before creating a 3D feature, use the Sketcher's transformation and array tools.

  1. Using the Sketcher Clone / Copy Tool:
    • Open the sketch in edit mode.
    • Box-select the geometry elements you want to copy.
    • Click the Clone or Copy tool in the Sketcher toolbar.
    • Move the duplicated elements to the desired location and apply constraints (dimensions, angles, or symmetries) to position them.
  2. Using the Polar or Rectangular Array Tool:
    • Select the sketch entities you want to pattern.
    • Click the Create rectangular array or Create polar array tool from the Sketcher tools menu.
    • Specify the number of columns, rows, spacing, and constraints in the pop-up dialog.
    • Constrain the patterned geometry using standard Sketcher constraints to keep the sketch fully defined.

Method 3: Transforming Entire Sketches Using the Draft Workbench

If you need to produce multiple copies of an entire 2D sketch outside the Sketcher without converting it to 3D first:

  1. Switch to the Draft Workbench.
  2. Select your sketch in the tree view.
  3. Use the Draft Array tools:
    • Ortho Array: Creates a linear multi-directional grid of the sketch.
    • Polar Array: Creates circular copies around a center point.
    • Path Array: Distributes the sketch along a specified wire or curve.
  4. The resulting array retains parametric links to the original sketch. When you edit the original sketch, all copies update automatically.