Understanding the Tip in FreeCAD PartDesign Body

In FreeCAD’s PartDesign workbench, the "Tip" is the specific feature within a Body that represents its active, final output state. This article explains what the Tip is, how it controls the sequential modeling history, why moving it is useful for editing, and how it affects downstream operations in other workbenches.

The Core Concept of the Tip

A PartDesign Body is built using a strict single-solid, feature-based modeling sequence. Each operation—such as a Pad, Pocket, Revolution, or Fillet—builds directly upon the result of the previous operation.

The Tip marks the end of this active build sequence. It indicates to FreeCAD which operation in the tree represents the completed state of the solid. Even if a Body contains dozens of features, only the geometry up to the designated Tip is rendered as the current solid.

Automatic Tip Advancement

By default, FreeCAD automatically manages the Tip. Whenever you create a new additive or subtractive feature, the software places that feature at the bottom of the tree and automatically sets it as the new Tip. A small icon overlay or bold text in the tree view typically designates which feature is currently the Tip.

Manually Setting the Tip

You can override the automatic behavior by right-clicking any feature in the tree view and selecting Set tip. Setting an earlier feature as the Tip acts like a rollback mechanism.

When you set the Tip to an earlier feature:

• Features below the Tip become inactive: Any features located after the Tip in the tree will no longer be visible in the 3D view. They are not deleted; their computation is simply suspended.
• Inserting new features: If you create a new sketch or feature while the Tip is set to an intermediate step, the new feature is inserted directly after that Tip, rather than at the very end of the tree.
• Debugging errors: If a feature fails to compute (turns red in the tree), setting the Tip to the feature immediately before the failure lets you inspect the valid geometry and resolve the root cause.

Once changes are complete, you can restore the full model by right-clicking the last feature in the list and selecting Set tip again.

Impact on External Workbenches

External workbenches—such as TechDraw, Assembly, FEM, and Path (CAM)—interact exclusively with the Body's Tip. When you create a 2D technical drawing or insert a part into an assembly, FreeCAD references the shape provided by the Tip. If the Tip is mistakenly left on an earlier operation, external tools will show an incomplete model. Ensuring the Tip is placed on the intended final feature guarantees that all downstream references stay accurate.