If you’ve already mastered the basics of 2D sketching in SolidWorks, you’re ready for the next major milestone: part modelling. This blog post will help reinforce the core concepts introduced in the video and provide a clear understanding of the modelling tools used to transform sketches into real parts.

Whether you’re aiming to design simple components or complex mechanical assemblies, understanding how 2D sketches evolve into 3D features is crucial. In this introduction, we explore the foundational modelling tools—Boss-Extrude, Revolve, and several sketch-enhancing techniques like Power Trim and Smart Dimensioning—that form the backbone of most SolidWorks parts.

What Is Part Modelling?

In SolidWorks, part modelling refers to the process of building individual 3D components using a combination of sketches and features. You begin by drawing a 2D shape on a flat plane—called a sketch—and then apply 3D features that give the sketch depth, volume, and complexity.

Boss-Extrude: The Foundation of 3D Modelling

The Boss-Extrude feature is often the first modelling tool that new users encounter—and for good reason. It’s the go-to method for converting a flat sketch into a solid body by 'pulling' it into the third dimension.

What it does: Boss-Extrude takes a closed 2D sketch and extrudes it in a straight line to create a 3D solid.

Use cases: Great for building blocks, walls, flanges, and any feature with a uniform cross-section.

Common options available:

  • Blind: Specifies a fixed distance in one direction.
  • Mid-Plane: Splits the extrusion equally on both sides of the sketch.
  • Through All / Up to Surface: Allows extrusion up to other geometry or surfaces for more adaptive design.

Revolve: When Rotation Meets Design

While extruding stretches a shape linearly, the Revolve feature gives you the power to spin a sketch around an axis—useful for generating round, symmetrical parts.

What it does: Creates a solid or surface by rotating a 2D profile around a central axis.

Use cases: Perfect for items like wheels, pulleys, cylinders, or anything that’s radially symmetric.

Key elements:

  • The sketch must define the profile of the part.
  • A centreline (or selected axis) tells SolidWorks where and how to revolve the profile.

Power Trim: Clean and Quick Sketching

Before any feature can be applied, your sketch needs to be clean—free of excess lines or overlapping geometry. The Trim Entities tool helps achieve this, and Power Trim is its most intuitive and powerful mode.

What it does: Lets you trim (cut away) sketch segments simply by dragging your cursor across them.

Why it’s useful: It speeds up sketch clean up, especially in complex shapes where multiple lines intersect.

Bonus tip: Trimmed segments often retain their original constraints by being converted into construction geometry, helping preserve the integrity of your design.

Smart Dimensioning: The Glue That Holds Your Sketch Together

A sketch without dimensions is just a suggestion. The Smart Dimension tool adds critical size and positional information to your sketches, turning them into well-defined building blocks for 3D features.

What it does: Adds size and spacing dimensions to sketch entities.

Why it's important: Dimensions make your sketches predictable, editable, and parametric.

Notable capabilities:

  • Dimensions can be applied to points, lines, angles, and arcs.
  • You can reference centrelines or construction geometry to define symmetrical parts.

Merge Result: Small Checkbox, Big Impact

When adding new geometry via features like Revolve or Boss-Extrude, the Merge Result option ensures your additions are integrated into the existing part, not created as separate bodies.

When to use: In most single-part workflows where you want a unified, solid model.

When to disable: If you're intentionally creating multiple bodies (e.g. for multi-body parts or Boolean operations later).

What’s Next?

This post covered some of the most essential building blocks in SolidWorks part modelling. As you progress, you’ll combine these with other features—like Cut-Extrude, Fillet, Shell, and Patterning—to produce robust, production-ready designs.

🎥 Don’t forget to check out the video if you haven’t already—it puts all of these concepts into context by showing you exactly how the part is built inside SolidWorks.

In the next video and blog post, we’ll look at how to start removing material from your model, rounding edges, and preparing your design for more advanced shapes and detailing.