Circle and arc tools in Solidworks - Step-by-Step Guide

Introduction

Circle and arc tools in SolidWorks help you draw round shapes easily. They solve the problem of creating perfect circles or arcs without manual drawing errors.

When you need to draw a perfect circle for a hole or round feature in your design.

When you want to create an arc to represent a curved edge or path.

When you need to define a circular pattern or boundary in your sketch.

When you want to quickly add round shapes without complex calculations.

When you need to modify or trim parts of a circle or arc in your sketch.

Steps

Step 1: Click

- Sketch tab > Circle tool dropdown

Circle tool options appear including Center Circle and Perimeter Circle

💡 Use Center Circle to draw a circle by defining center and radius

Step 2: Select

- Center Circle tool

Cursor changes to circle drawing mode

💡 Click once to set center point, move mouse, then click again to set radius

Step 3: Click

- Sketch tab > Arc tool dropdown

Arc tool options appear including 3 Point Arc, Centerpoint Arc, and Tangent Arc

💡 Choose 3 Point Arc to define arc by start, end, and a point on the arc

Step 4: Select

- 3 Point Arc tool

Cursor changes to arc drawing mode

💡 Click three points in order: start, end, and arc height point

Step 5: Use

- Modify handles on circle or arc

Adjust size or shape interactively

💡 Drag handles to resize or reposition arcs and circles

Before vs After

Before

Sketch has no round shapes, only straight lines and points

After

Sketch includes precise circles and arcs with defined sizes and positions

Settings Reference

Circle type

📍 Sketch tab > Circle tool dropdown

Choose how to define the circle: by center and radius or by perimeter points

Default: Center Circle

Arc type

📍 Sketch tab > Arc tool dropdown

Select method to draw arcs based on points or tangency

Default: 3 Point Arc

Display dimensions

📍 Sketch tab > Display/Delete Relations

Control visibility of dimension labels on circles and arcs

Default: Show

Common Mistakes

Trying to draw a circle by freehand without using the Circle tool

This causes inaccurate shapes and errors in the sketch

Always use the Circle tool to create perfect circles with defined centers and radii

Using the wrong arc tool for the desired shape

It can create arcs that do not match the design intent or are hard to control

Choose the arc tool that fits your needs: 3 Point Arc for flexible arcs, Centerpoint Arc for arcs with known center

Summary

Circle and arc tools let you draw perfect round shapes easily in SolidWorks sketches.

Use the correct tool type to match your design needs for circles or arcs.

Adjust and dimension these shapes precisely for accurate modeling.

Practice

1. What is the main difference between a circle and an arc in SolidWorks?

easy

A. A circle cannot have a radius dimension.

B. A circle needs three points; an arc needs only one point.

C. An arc is always larger than a circle.

D. A circle is a full 360-degree shape; an arc is only a part of a circle.

Solution

1. Step 1: Understand circle properties

   A circle is a complete round shape with 360 degrees.

2. Step 2: Understand arc properties

   An arc is a segment of a circle, less than 360 degrees.

3. Final Answer:

   A circle is a full 360-degree shape; an arc is only a part of a circle. -> Option D

4. Quick Check:

   Circle = full shape, Arc = partial shape [OK]

Hint: Circle is full round; arc is just a slice [OK]

Common Mistakes:

• Thinking arcs are full circles
• Confusing number of points needed
• Believing arcs are always bigger than circles

2. Which of the following is the correct way to create a circle in SolidWorks?

easy

A. Select center point, then drag to set radius

B. Draw three random points anywhere

C. Draw a line and convert it to a circle

D. Use the arc tool and close it manually

Solution

1. Step 1: Recall circle creation method

   In SolidWorks, you start by selecting the center point.

2. Step 2: Set the radius by dragging

   After the center, dragging sets the circle's radius.

3. Final Answer:

   Select center point, then drag to set radius -> Option A

4. Quick Check:

   Center + drag = circle creation [OK]

Hint: Pick center first, then drag radius [OK]

Common Mistakes:

• Trying to create circle with three random points
• Using arc tool for full circle
• Converting lines to circles incorrectly

3. What will happen if you try to create an arc in SolidWorks by selecting only two points?

medium

A. The arc will be created with default curvature between the points.

B. SolidWorks will show an error because three points are needed.

C. A full circle will be created instead of an arc.

D. The arc will be created but with zero radius.

Solution

1. Step 1: Understand arc creation inputs

   An arc needs start and end points plus curvature control.

2. Step 2: Two points create arc with default curvature

   If only two points are selected, SolidWorks assumes a default curvature to form the arc.

3. Final Answer:

   The arc will be created with default curvature between the points. -> Option A

4. Quick Check:

   Two points = arc with default curve [OK]

Hint: Two points make arc with default curve [OK]

Common Mistakes:

• Believing three points are always required
• Expecting error on two points
• Confusing arc with full circle creation

4. You tried to create a circle but SolidWorks does not let you set the radius. What is the likely cause?

medium

A. You tried to draw the circle outside the sketch plane.

B. You selected the arc tool instead of the circle tool.

C. You did not select the center point first.

D. You forgot to add a dimension after drawing.

Solution

1. Step 1: Check tool selection

   If the arc tool was selected, radius setting behaves differently.

2. Step 2: Confirm center point selection

   Without selecting the center point first, SolidWorks cannot define the circle radius.

3. Final Answer:

   You did not select the center point first. -> Option C

4. Quick Check:

   Center point needed before radius [OK]

Hint: Always pick center point first for circle [OK]

Common Mistakes:

• Using arc tool by mistake
• Trying to draw off the sketch plane
• Assuming dimension is needed before radius

5. You need to create an arc that exactly fits between two points with a specific radius in SolidWorks. Which steps should you follow?

hard

A. Use the circle tool and delete part of it to form an arc.

B. Select the arc tool, pick start and end points, then set the radius dimension.

C. Draw a line between points, convert it to an arc, then set radius.

D. Draw a circle with the radius, then trim it to the two points.

Solution

1. Step 1: Use arc tool with start and end points

   Select the arc tool and click the two points where the arc should start and end.

2. Step 2: Apply radius dimension to control curvature

   Set the radius dimension to define the exact curvature between those points.

3. Final Answer:

   Select the arc tool, pick start and end points, then set the radius dimension. -> Option B

4. Quick Check:

   Arc tool + points + radius dimension = exact arc [OK]

Hint: Arc tool + points + radius dimension for exact arc [OK]

Common Mistakes:

• Trying to trim circles instead of using arc tool
• Converting lines to arcs incorrectly
• Deleting circle parts to make arcs