Alibre Options: Creating Patterns Using Standard Sketch Shapes9 Jun, 2006 By: Michael Todd
Save time when creating duplicate 3D features with the Feature Pattern tool.
In last month's tech tip, I discussed how to save time when creating duplicate 3D features by using the Feature Pattern tool. This month, I will cover another time-saving pattern option -- this time in sketch mode.
Alibre Design offers several standard sketch shapes that you can use to create patterns with a large number of instances -- for example, creating a hole pattern for airflow in a sheet metal plate. Using the standard sketch shapes will not only save you modeling time but will save regeneration time and reduce file size because standard sketch shape patterns are treated as one entity in Alibre Design. You can use standard sketch shape patterns to create various 3D features, but in this example I will use them for a sheet metal cut feature.
Creating the Pattern
1. Create a 3D model on which you want to place a pattern. I will begin with a sheet metal plate (approximately 8.0" x 3.0") that needs a hole pattern for airflow (figure 1).
Figure 1. Sheet metal part.
2. In the work area, select the face to use as the sketch plane (the face will highlight in a different color when you select it) and then select the Activate 2D Sketch tool.
3. Choose the Sketch Shapes menu from the Sketching toolbar and then select the shape you wish to use (figure 2). For this example, I will use the Double D shape. After selecting the appropriate tool, the Shape dialog box appears (figure 3).
Figure 2. Sketch shapes are available on the Sketching toolbar.
Figure 3. The Double D Shape dialog box appears after selecting the Double D Shape tool.
4. Fill in the appropriate values for the shape. For the double D shape, I need to specify the lengths of two sides and an angle, if desired. I will use 1.0" for the XL length, 0.50" for the YL length, and 90 degrees for the angle.
5. Select the pattern type to use. The pattern options are: single instance (no pattern), linear pattern, arc pattern, circle pattern and grid pattern (figure 4). For this example, I will select the grid pattern. You will have various options to specify depending on the pattern you choose.
Figure 4. The Double D Shape dialog box with the grid pattern selected, showing the parameters to specify.
6. Move your mouse pointer over the work area, and you will see a preview of the pattern has attached to the mouse pointer. Move the pattern around until it is approximately where you want it and then click in the work area to place the pattern. After placing the pattern, you can continue to modify the parameter values in the dialog box, and the pattern will update in the work area. When you are satisfied with the pattern, choose Apply to create the sketch (figure 5).
Figure 5. The sketch is created after selecting the Apply button.
7. You will notice that another copy of the sketch pattern has attached to the mouse pointer. You can choose to place another copy in the sketch, or you can select the Close button to exit the Shape dialog box. In this case we do not need another pattern, so I will choose Close.
8. You will notice if you move your mouse pointer over one of the shapes that the entire pattern highlights. When you use this method, the sketch shape pattern is created as one sketch entity.
9. Next you need to dimension the sketch to the model. You will notice in figure 6 that I only need to dimension one of the shapes, because the parameters of the diameter and distances between them are set in the Shape dialog box.
Figure 6. The sketch is fully dimensioned.
10. If you need to edit the parameters of the sketch shape pattern, you can right-click on one of the shapes and choose Edit. The Shape dialog box appears, and you can change any of the parameters.
11. Finally, I need to use the sketch shape pattern to create a 3D feature. I will use the sheet metal cut feature for this example. To do this, select the Cut tool from the Sheet Metal Modeling toolbar. Because I am choosing the 3D feature while in sketch mode on this sketch, the Cut dialog box will appear with the sketch field already populated (figure 7).
Figure 7. The Cut dialog box appears with the sketch field already populated.
12. Select OK to create the cut. The sheet metal plate with an airflow hole pattern is complete (figure 8).
Figure 8. The completed sheet metal plate.
Using a standard sketch shape pattern, I have created a hole pattern in a sheet metal plate using only two steps -- one sketch and one feature.
Look for next month's Alibre Options article, where I will explore another great feature of Alibre Design. Until then, look for me as the Alibre Assistant online in Alibre Design.
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!