Creating Contoured and Plastic Parts - Autodesk Inventor 2010: No Experience Required - page 420

3. Set the view in the Design window to the front view.
You need to pattern the lines in the sketch. To make things easier
to see, I've colored the lines that you'll pattern. Rather than doing a
simple input of numbers, I also wanted to use this opportunity to
show a couple more examples of the power of parametric sketches.
4. Start the Rectangular Pattern tool from the Pattern panel of the
Sketch tab.
5. For the Geometry, select the orange, vertical line.
6. Click the arrow icon for Direction 1, and pick a horizontal line in the
sketch to establish the direction.
7. Highlight the value for the distance between instances of the pattern.
Then, click the 1.500-inch dimension in the sketch to use its value.
You've established the distance between the lines in the pattern.
Now you'll create an equation in the dialog to set the number.
To calculate the number of instances in the pattern you divide the
length of the pattern by the distance between instances.
8. Highlight the value in the instances input.
9. Type a left parenthesis, and then select the 33-inch width dimension.
10. Add a slash, and then select the 1.5-inch dimension you selected for
the distance.
11. Add a right parenthesis, a hyphen, and the number one.
This equation says that you'll divide the width by the distance between
the lines and then subtract one of the instances. See Figure 8.63. The
reason for using an equation is to automatically adjust the pattern if you
decide to change the spacing of the lines or change the width of what
will be the boundary of your grill.
12. Click OK to create the pattern of lines.
13. Repeat the rectangular pattern for the red, horizontal lines, using the
.500-inch spacing dimension and the 33-inch height dimension. See
Figure 8.64 to verify the equation.
14. Click OK to create the pattern.
15. Finish the sketch, and save the part.