Using the Loft Command on Sketches 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.
Combining Those Sketches
While extrude can do some pretty interesting things, there are a few things that only the loft command will do. For instance, varying the size or shape of a sketch along an extrusion is not possible. But with a Loft in Inventor, we can make a part with a cross-section that is constantly changing. Maybe you have a part that is supposed to connect a square and a circle. Or one that needs to fit inside a circular hole but has to be square later to weld onto a surface. The loft command can come in very handy for this type of work, and I've used it several times for neat-looking parts that I couldn't have made otherwise.
In this tutorial, you'll learn how to combine several similar sketches into one part using a loft command. The final part has a varying cross-section and a smooth appearance that would not be possible without the loft command.
How to Use the Loft Command in Inventor
Loft it! (or rather, them)
I was planning on using the same sketch we made together in the previous tutorials, but Inventor didn't like that one. I'm not surprised, since it's pretty complicated. I didn't waste too much time trying it, but I made some circular shapes to try the loft on, since they will work just as well.
First, draw a circle. Anywhere, any size. Then add a work plane to put another circle on, of a different shape. How do you do this? See Picture 1. Click on the arrow underneath the "Plane" command, and select "Offset from Plane." Then click the plane that has your original circle, (or offset it from one of the origin planes, as the red arrows suggest), and enter a distance to offset the plane. If you are happy with the distance, press the green check mark to approve. Then start a sketch and draw another circle. I drew two circles and one ellipse (see Picture 2) to show the versatility of the loft command. I could have done a square, though, or even a polygon.
To start the loft command, click on the "Loft" button next to the "Revolve" command. You should see the menu that is shown in Picture 3.
To add shapes, just select them with your mouse. You can immediately see the effect with the live preview. The three shapes I selected show up in Picture 4 in the live preview.
Once you are happy with the shape that you made, click Ok. Your shapes will be combined, and you will be left with one part. I got the part in Picture 5, which I could have never gotten from a simple extrude command.
Try a few shapes and see what you get. The loft command can get very handy for merging two dissimilar parts, or just making something that looks cool. But if you are in this to make something look cool, there are some other neat tools straight ahead.