The Sweep Command in AutoDesk Inventor

This is just one hub in a series of 15 hubs on using AutoDesk Inventor for 3D modeling. The index hub is here.

There are many ways to turn a 2D sketch into a 3D object, and extruding along a curve is a very interesting one. It's called a "Sweep." Think play-dough but better. I could spend all day thinking up ways to use this command, but I've only shown one below. Taking any shape, simple or complex, as long as it's 2D, and dragging it along a curve can produce some really neat results really quick!

In this tutorial we'll learn how to take the shape we drew in the sketch tutorial and turn it into an interesting shelving device. I don't guarantee the shelf's usefulness, but the command is invaluable! Our dovetail-notched rectangle that we made so long ago is turning up in many different ways, and this is one of the more interesting ones.

Since we already have the sketch drawn, we'll start by making a spline to extrude it along. If you haven't done the sketch tutorial, or don't have a sketch of your own, head back to that tutorial and try it out. You have to know how to sketch to get the sweep down right.

To start, make a new sketch that is perpendicular to the sketch we've already drawn. This sketch is for the spline, which we'll be drawing next.

Making A Spline

To make a spline, click on the "Spline" command, right next to the "Rectangle" command on the top of the screen. We'll need to make a spline that goes though the shape we've drawn, or the sweep won't work correctly.

Start by clicking anywhere on the screen. Then click another point somewhere that you want your spline (basically just a curvy line) to go through. When you think you have enough points (usually 2-5 will do), then press enter to complete.

Editing a Spline

You'll notice that the spline is automatically made. But it doesn't have to stay the same shape that the computer makes it. You can edit your spline to make it any curve you like, provided that the curve goes through the points you've specified.

The spline has little square symbols wherever you have made a point. Click on one of these to see how to edit it. Notice that the point has two "handles" that come out of it - check Picture 1. These handles are always aligned.

Click on the square at the end of a handle and move it. You'll notice that when you change the angle of the handle, the angle of the spline at that point changes as well. You can see in Picture 2 how extreme you can make the curve just by moving these handles.

Changing the length of the handles makes a difference as well - it changes how "strong" the effect of the angle is. A longer handle means that the angel at that point on the spline will be harder to change by the next point in the spline.

My spline and sketch are shown in Picture 3. Make sure your spline goes through your sketch. Once you are done with your spline, exit the sketch and get ready to sweep.

The Sweep Command

Click on the "Sweep" command on the model tab right underneath "Loft." You should see a menu like the one in Picture 4. Using the process we taught you in the sketch tutorial, notice the arrow buttons that are there. For the first arrow button you'll need to select the profile, and for the second button you'll need to select the path.

You can choose to make a solid object or an outline. You can also choose to keep the profile parallel the entire way along the path, kind of like calligraphy. I chose the defaults, and the preview shows up in Picture 5. Once you've decided you like the result, click Ok.

My interestingly designed shelf system appeared as Picture 6 shows it. See how you could make dovetail shelves to slide along that groove? It would certainly be one unique shelf. What are you going to make with the sweep command?