It’s tempting to jump straight into 3D modeling, but without a strong 2D foundation, your designs will fall apart. Just like a house needs a solid foundation, your 3D parts need robust 2D sketches to support them. In this Chapter 1 Lesson 2, we break down one of the most important rules of CAD: 2D drives 3D.

Using the example of a simple washer, we show how 2D sketches (two circles) transform into a 3D part once thickness is added. Along the way, you’ll learn why focusing on 2D first sets you up for success, helps you avoid mistakes, and ensures your models remain stable as you build.

What you’ll learn in this episode:

• The difference between 2D and 3D CAD
• Why 2D is the foundation of every good model
• How a simple sketch evolves into a 3D part
• The key principle: 2D drives 3D