## Use of 3-D sketch feature in SolidWorks

3-D sketches are lines, splines or a sketch made by using different sketching tools in SolidWorks.

3-D sketches are used as paths or guide curves while sweeping.

TIP: you cannot use patterns or mirrors while working with 3-D sketches.

Different tools used while working with 3-D sketches:

Centerline – Creates construction geometry.

Convert Entities – Creates one or more entities in a 3D sketch by projecting an edge, loop, face, external curve, external sketch contour, set of edges, or set of external curves onto the sketch plane.

Face Curves – Extracts 3D iso-parametric curves from faces or surfaces.

Sketch Fillet – Rounds the intersections of sketched lines.

Sketch Chamfer – Bevels the intersections of sketched lines.

Intersection Curve – Creates a sketched curve at intersections.

Trim Entities – Trims or extends a sketch entity in a 3D sketch.

Extend Entities – Extends a sketch entity in a 3D sketch.

Construction Geometry – Converts sketched curves in a 3D sketch to construction geometry.

TIP: Spline on surface is only available when working with 3-D sketches.

Step by step use of 3-D sketches:

You can create 3D sketch entities on a working plane, or at any arbitrary point in 3D space.

3-D sketch icon can be found in weldments tools, or from insert menu.

Initiating 3-D sketch tool:

We can initiate this tool b using weldments tool pallet.

Go to weldments tools

Click on 3-D sketch to use this tool in SolidWorks.

Or we can start using this tool by starting from insert tab.

Go to insert, select 3-D sketch.

This is the representation of origin while using this sketch tool.

To understand the XY in our tool, lets understand the basics of Cartesian geometry.

The 3 planes in 3-D are:XY, YZ, XZ

These are the interface between any two axes, for example XY is the face between the intersection of X and Y axes.

Now working on ZX plane lets create a sketch.

In this example, we will create a profile for sweeping , this profile will be on different planes.

There are two ways of doing this:
First is the normal method of creating reference planes and sketching on them.
The second, which is more efficient method of sketching is using 3-D sketch tool. Because of this tool you can sketch on different planes without using reference plane feature in Solidworks.

Now select YZ plane and add this sketch.

You can change the plane selected by using the ‘tab’ key.

This is how the sketch looks in 3-D view. We have sketched in 2 planes without using reference plane feature.

This user friendly behavior is what makes SolidWorks a leading software in Designing.

Now, change the selected plane and add this sketch to our original sketch.

This is how our sketch looks now, in 3-d view.

Add fillets to make it more realistic.

This sketch was profile for sweeping. Now to draw the sweep tool, select the origin and sketch a circle.

Use sweep feature in SolidWorks to sweep the profile across the path sketched.

The use of sweep feature.

Render the part to get the final result.