Duplicate Object¶

In one sentence: Copy selected features or objects into the active Body as fully independent duplicates with no parametric link back to the originals.

Overview¶

Workbench: Part Design · Menu: Edit → Duplicate Object
Toolbar: none · Shortcut: none

When the Part Design workbench is active, the standard Edit → Duplicate Selection menu item is replaced by Edit → Duplicate Object (PartDesign_DuplicateSelection). This PartDesign-aware variant wraps the standard Std_DuplicateSelection operation and then automatically inserts the newly created objects into the currently active Body.

The result is one or more deep copies of the selected objects. The copies share no parametric link with the originals: changing the original feature does not affect the duplicate, and vice versa. All properties — sketch geometry, dimensions, references — are copied at the moment of duplication and then become entirely independent.

Intuition¶

Imagine photocopying a page of technical drawings. The photocopy looks identical to the original at the moment it is made, but writing on the photocopy does not change the original and any later changes to the original do not appear on the photocopy. Duplicate Object works the same way: you get a snapshot of the selected features, frozen in time, placed in the active Body.

This is the opposite of Clone, which creates a live link that always reflects the current state of the source. Duplicate Object creates a dead copy that you are free to edit independently.

When to use it¶

You want to start a design variant from the current state of a feature or Body, keeping the original untouched and making independent modifications to the copy.
You want to reuse a sketch as the starting point for a second, similar sketch, without the second sketch being linked to the first.
You are copying a feature into a different Body that has similar geometry requirements but different final dimensions.
You need a fallback snapshot of the current feature state before attempting a risky edit.

When NOT to use it¶

You want the copy to stay synchronized with the original — use Clone instead; it creates a live parametric link.
You want to reuse geometry from another Body without copying it — use Shape Binder or Sub-Shape Binder, which reference the original geometry without duplicating it.
You want to move a feature between Bodies without copying — use Move Object To… instead.
You want to move a feature to a different position in the same Body's history — use Move Object in Tree instead.

Step-by-step walkthrough¶

Prerequisites: At least one object must be selected in the model tree, and a Body must be active (for the duplicate to be inserted into it automatically).

Activate the target Body. Double-click the Body in the model tree so it appears bold. If no Body is active the duplicate is still created, but it will not be inserted into a Body automatically.
Select the feature(s) to duplicate. Click the feature in the model tree. Multiple features can be selected with Ctrl+click.
Launch the command. Choose Edit → Duplicate Object from the menu. Because the PartDesign workbench is active, this invokes PartDesign_DuplicateSelection rather than the standard Std_DuplicateSelection.
Inspect the result. New objects with the same names (plus a numeric suffix to make them unique) appear in the model tree. If a Body was active, they are placed inside that Body. The last new object is made visible; all others are hidden.
Edit the duplicate independently. Double-click the duplicated feature to open its task panel and change dimensions, add constraints, or otherwise modify it. The original remains unchanged.

Tip

If you duplicate a Sketch, the duplicate is a completely independent Sketcher::SketchObject. Open it and you will find all the geometry and constraints present, but with no link back to the source sketch. You can freely add, remove, or change constraints.

Tip

After duplication the duplicate features' Placement values are identical to the originals. If you are duplicating into the same Body, consider adjusting positions or sketch attachment offsets to avoid the duplicate sitting exactly on top of the original.

Parameters¶

Duplicate Object has no interactive parameter panel — it executes immediately on invocation. The resulting objects inherit all properties from the originals. After duplication, each property is editable independently in the Properties panel (View → Panels → Properties).

Behaviour details¶

Aspect	Value / Description
Link to original	None. The duplicate is fully independent.
Property values	Copied from the original at the time of duplication.
Sketch geometry	All points, edges, and constraints are deep-copied. External references in the sketch (links to Body geometry) may need to be re-established if the duplicate is in a different Body context.
Feature name	Same base name as the original plus a numeric suffix for uniqueness (e.g. `Pad` → `Pad001`).
Visibility	The last duplicated object is shown; all others are hidden.
Body insertion	If a Body is active, all new `PartDesign`-allowed features are added to that Body. Features that are already in a Body are not moved (issue #6278).
Undo	The entire duplication is wrapped in a single undo transaction labelled "Duplicate a Part Design object".

Advanced usage¶

Duplicating into a different Body¶

Activate the destination Body before invoking the command. The new features are inserted into the active Body. If the source feature was in a different Body and contained references to that Body's geometry (for example, a sketch with an external edge constraint), those references will be broken in the copy and must be re-established manually.

Duplicating multiple features at once¶

Select several features in the model tree (Ctrl+click) before invoking the command. All selected features are duplicated in a single undo transaction. Note that if features have dependencies on each other (for example, a Pad that uses a Sketch), select both the Sketch and the Pad to avoid the duplicate Pad referencing the original Sketch.

Using duplication for design variants¶

A common workflow:

Complete a base feature to a known-good state.
Duplicate the feature.
Rename the duplicate (right-click → Rename) to reflect the variant.
Edit the duplicate's parameters for the new variant.

Both the original and the variant coexist in the model tree. You can switch the Body's Tip property to expose one or the other as the Body's output shape.

Relationship to Std_DuplicateSelection¶

PartDesign_DuplicateSelection calls FreeCADGui.runCommand('Std_DuplicateSelection') internally. The actual deep-copy logic lives in the standard command. The PartDesign wrapper adds the post-processing step that detects which new objects were created and inserts them into the active Body. If no Body is active the behaviour is identical to the standard command.

Common mistakes and pitfalls¶

External references in duplicated sketches become broken

Cause: When a Sketch in the original Body has External Geometry constraints (red reference edges imported from the Body solid), those references point to specific sub-shapes by topological name. In a different Body context the same names may not exist.
Fix: After duplication, open the sketch, delete the broken external geometry (shown in red or yellow), and re-attach it to the corresponding geometry in the new Body.

Duplicate placed exactly on top of original, hard to distinguish

Cause: The duplicate inherits the same Placement as the original. For 3D features inside the same Body, they occupy the same space until you edit their parameters.
Fix: Either immediately open the duplicate's task panel and change a dimension, or set an AttachmentOffset on the duplicate's sketch to shift it to a different position.

Duplicate is not inserted into the active Body

Cause: The feature is already a member of another Body. PartDesign_DuplicateSelection skips features that already belong to a Body (issue #6278) to avoid moving them unintentionally.
Fix: If you want the duplicate inside the current Body, use Move Object To… on the duplicate after it is created, or copy the feature manually via the Properties panel.

Duplicating a Body duplicates its entire feature tree

Cause: Std_DuplicateSelection deep-copies the selected object and all its children. Selecting a Body copies every feature inside it, which may create a very large number of new objects.
Fix: Select only the specific features you need, not the Body container itself, unless you genuinely want a full copy of the Body.

Python API¶

Duplicate Object does not have a dedicated Python class — it invokes the standard Std_DuplicateSelection command through the GUI command system. To duplicate programmatically, use FreeCAD.ActiveDocument.copyObject():

import FreeCAD as App
import FreeCADGui as Gui

doc = App.activeDocument()

# Get the feature to duplicate
source = doc.getObject("Pad")

# Deep-copy the object (with = True means copy children too)
duplicate = doc.copyObject(source, True)

# If a Body is active, add the duplicate to it
body = doc.getObject("Body")
if body and hasattr(duplicate, "isDerivedFrom"):
    import PartDesign
    if PartDesign.Body.isAllowed(duplicate):
        body.addObject(duplicate)

doc.recompute()
print(duplicate.Label)   # e.g. "Pad001"

To invoke the command exactly as the menu item does (including the Body insertion logic):

import FreeCADGui as Gui

# Select the features you want to duplicate first
# Gui.Selection.addSelection(...)

Gui.runCommand("PartDesign_DuplicateSelection")

Key behaviour of the underlying copy mechanism¶

Aspect	Description
`doc.copyObject(obj, True)`	Deep-copies `obj` and all its children into the same document. Returns the top-level copy.
Property values	Scalar, string, and placement properties are value-copied. Link properties may still point to original objects — check and update as needed.
Label	Assigned automatically by FreeCAD to ensure uniqueness (usually base name + numeric suffix).
Name	Also made unique, following FreeCAD's internal naming rules.