Direct Editing with Press Pull

1. The "Swiss Army Knife" of Fusion 360

The Press Pull tool is often called the "Swiss Army Knife" of Fusion 360 because it's not a single command, but rather a contextual tool that intelligently combines three different functions into one. Its behavior changes depending on what you select.

The three main contexts are:

• When you select a sketch profile: Press Pull acts as the Extrude command.
• When you select an edge: Press Pull acts as the Fillet command to round the edge.
• When you select a face: Press Pull acts as the Offset Faces command to move the face.

This lesson's focus is on the third behavior—modifying faces—as it's the most distinct function of the tool.

To see all three of these behaviors in action, let's watch a concise overview.

2. The Core Function: Offset Faces

As you saw in the video, the most powerful use of Press Pull is for directly modifying the faces of an existing 3D body. When you select a face, the Offset Faces command is invoked. This is where a crucial distinction comes into play, which directly impacts your design's timeline and editability.

You have two main options for the Offset Type:

1. Modify Existing Feature (often the 'Automatic' choice)
2. New Offset

Understanding the difference is vital for creating robust and editable models.

To summarize and reinforce that reading:

• Modify Existing Feature: This is like a time machine. It finds the original feature that created the face (e.g., the Extrude distance or a sketch dimension) and changes it. No new feature is added to your timeline. This keeps your timeline clean, but as the document notes, it can trigger a lengthy recomputation of all subsequent features, which can sometimes lead to errors in complex models.

• New Offset: This option adds a brand new Offset Faces feature to your timeline. It's an independent operation that simply pushes or pulls the selected face from its current position. This makes your timeline longer but is often more stable, as it doesn't force a recomputation of the entire model history.

Let's see a visual demonstration of this exact concept.

Choosing between these two depends on your goal. For simple, parametric adjustments (like changing the height of a box), Modify Existing Feature is great. For more complex modifications or when working on imported models that have no timeline, New Offset is your go-to.

3. Key Advantages of Press Pull

So, why use Press Pull instead of just finding the original feature and editing it? Press Pull has unique strengths, especially with complex geometry.

Modifying Curved Surfaces

You cannot use the Extrude tool on a curved surface like the side of a cylinder. Press Pull, however, handles this easily, allowing you to change the diameter of a hole or cylinder directly.

Intelligent Face Extension

If you try to Extrude an angled face, it will project straight out. If you Press Pull that same face, it will extend the face while maintaining its original angle relative to its neighbors.

This video demonstrates these two powerful advantages very clearly.

These capabilities make Press Pull an indispensable tool for quick edits and for working with shapes that aren't simple prismatic blocks.

4. Practice Exercise

Time to put this into practice. This exercise will help solidify the contextual nature of Press Pull and the difference between offset types.

1. Create a New Design.
2. Create a base shape: Sketch a 100mm x 50mm rectangle and Extrude it to a height of 30mm.
3. Experiment with Modify Existing Feature:
   • Press Q to activate the Press Pull tool.
   • Select the top face of the box.
   • In the dialog box, ensure Offset Type is Automatic.
   • Pull the face upwards by 20mm. Click OK.
   • Observe: Look at your timeline. Notice that no new feature was added. Right-click on the original Extrude feature and select Edit Feature. You will see its distance is now 50mm. You have modified the original feature.
4. Experiment with New Offset:
   • Undo your last change (Ctrl+Z or Cmd+Z) so the box is 30mm high again.
   • Press Q and select the top face again.
   • This time, in the dialog box, change Offset Type to New Offset.
   • Pull the face upwards by 20mm. Click OK.
   • Observe: Look at your timeline now. You should see a new feature called Offset Face after your original Extrude feature. You have added a new, independent operation.
5. Experiment on an edge and a curved face:
   • Undo the Offset Face feature.
   • Press Q and select one of the top long edges. Pull it to create a fillet. Notice the command changes to Fillet. Click OK.
   • Create a new sketch on the top face, draw a circle, and use Extrude to cut a hole through the box.
   • Press Q and select the cylindrical inner face of the hole. Pull it to change the hole's diameter. Notice this modifies the original circle sketch.

This hands-on comparison is the best way to internalize the different behaviors of the Press Pull tool.

Conclusion

You've now learned how to use Press Pull, a powerful and intuitive tool for direct model manipulation. It's your primary tool for pushing, pulling, and resizing the faces of your model.

Key Takeaways:

• Press Pull is a contextual command that can act as Extrude, Fillet, or Offset Faces.
• When modifying a face, the Modify Existing Feature option edits the source feature, keeping the timeline clean.
• The New Offset option adds a new, independent feature to the timeline, which can be more stable for complex edits.
• Press Pull excels at modifying curved surfaces and intelligently extending angled faces—tasks that are difficult or impossible with the Extrude tool.

In our next lesson, we will dive into the dedicated Hole tool. While you can make simple holes with Extrude or Press Pull, the Hole tool is specifically designed for creating standardized holes for fasteners, such as counterbores and countersinks, which are critical for assembling your 3D printed and DIY projects.