If you missed that post, you might want to check it out before diving into this one.

In this guide, we will explore the different methods for adding sketch entities and introduce sketch relations, a powerful tool that ensures well-constructed, parametric sketches. By understanding sketch relations, you can create sketches that adapt intelligently when modifications are made.

Two Ways to Create Sketches in SolidWorks

When adding sketch entities in SolidWorks , there are two primary methods:

Click-Click Method: This involves clicking once to start a line and clicking again to end it. This method is efficient when you need to create a continuous series of connected sketch entities.

Click-Drag Method: In this method, you click and hold the left mouse button, drag to set the length, and release to place the entity. This method does not automatically continue sketching additional entities.

Each method has its advantages, and the best approach depends on your workflow. You can even mix both methods within the same sketch. For example, when creating a channel profile, you might use the click-click method for the first two lines and then switch to click-drag to terminate the sketch without pressing Escape.

Experiment with both methods to see which one works best for you!

Understanding Parametric Sketching

One of the defining features of SolidWorks sketches is that they are parametric, meaning that they remain adaptable for future modifications. This is achieved through two important elements:

Sketch Relations – Define geometric constraints between sketch entities.

Dimensions – Assign specific measurements to control size and position.

In this post, we will focus on Sketch Relations, while Dimensions will be covered in the next article.

What Are Sketch Relations?

Sketch Relations are constraints applied to sketch entities that dictate their behaviour and interaction with other elements. These constraints ensure that sketches maintain proper relationships, even when modified.

Some of the most commonly used sketch relations include:

  • Coincident – Forces two points to occupy the same location.
  • Collinear – Ensures two or more lines lie along the same projection.
  • Parallel – Keeps two lines parallel.
  • Perpendicular – Ensures two lines meet at a right angle.
  • Equal – Makes two or more entities the same size (e.g., equal-length lines).
  • Horizontal/Vertical – Fixes lines along the horizontal or vertical axis.
  • Tangent – Ensures smooth transitions between curves and lines

Understanding and using these relations effectively will help you create well-defined, robust sketches.

Applying and Managing Sketch Relations

Automatic vs. Manual Relations

SolidWorks automatically applies certain sketch relations as you draw. For example, if you snap a line to the horizontal axis, a horizontal relation is automatically applied.

However, you can also manually apply relations by:

1. Selecting an entity (or multiple entities).

2. Choosing the desired relation from the Property Manager on the left panel or from the pop-up menu near your cursor.

3. Clicking Apply to confirm the relation.

To delete a relation, simply click on the relation icon in the graphics area or Feature Manager and press Delete.

Practical Example: Using Sketch Relations

Let’s walk through a basic example to demonstrate sketch relations in action:

Start a new sketch and select the Line Tool.

Click the origin (0,0,0 point). Since this is the only defined point in space when creating a new part, sketching from the origin is good practice.

Draw a horizontal line. Notice that SolidWorks automatically adds a horizontal relation.

Close the sketch profile by drawing additional lines.

Observe the perpendicular relation that SolidWorks adds when two lines meet at a right angle.

Manually modify a relation: If a vertical line is slightly off, select it and add a Vertical Relation manually.

Test the sketch behaviour: Click and drag different parts of the sketch to see how the relations influence movement. If everything behaves as expected, the relations are correctly applied.

Checking and Adjusting Relations

Before adding dimensions, it’s a good practice to test how your sketch behaves:

  • Click and drag lines and points to see if the shape deforms unexpectedly.
  • If needed, add additional relations to better constrain the sketch.
  • If an unwanted relation was added, delete it and replace it with the correct one.

Checking sketch relations early ensures a stable and well-defined sketch before moving on to dimensions.

In the next blog post, we will focus on adding dimensions to sketches and ensuring full definition. Stay tuned!