Copyright Goodheart-Willcox Co., Inc. Chapter 12 Solid Model Editing 323 Extruding Imprints to Create Features The imprinted 2D shapes can now be extruded to create new 3D solid features on the model. Use the Face Extrude option to extrude all four imprinted circles. 1. When you select the edge of the first circle, all features on that face are high- lighted, but only the circle you picked and the top face have actually been selected. If you pick inside the circle, only the circle is selected and highlighted. In either case, be sure to also pick the remaining three circles. 2. Remove the top face of the box from the selection set, if needed. 3. The depth of the extrusion is .16 units. Remember to enter –.16 for the extrusion height since the holes remove material. The angle of taper for extrusion should be 35°. Your model should look like Figure 12-18A. 4. Extrude the small diameter of the four tapered holes so the holes intersect the bottom of the solid body. Select the holes by picking the small diameter circles. Instead of calculating the distance from the bottom of the chamfer to the bottom surface, you can simply enter a value that is greater than this distance, such as the original thickness of the object. Again, since the goal is to remove material, use a negative value for the height of the extrusion. There is no taper angle. Your model should now look like Figure 12-18B. Moving Faces to Change Model Size The next step is to use the Face Move option to decrease the length and thickness of the solid body. 1. Select either end face and the two holes nearest to it. Be sure to select the holes and the countersinks. Move the two holes and end face two units toward the other end, thus changing the object length to four units. 2. Select the bottom face and move it .5 units up toward the top face, thus changing the thickness to .5 units. See Figure 12-19. Figure 12-17. The initial setup for the tutorial model. A B Figure 12-18. A—The imprinted circles are extruded with a taper angle of 35°. B—Holes are created by further extrusion with a taper angle of 0°. Figure 12-19. The length of the object is shortened and the height is reduced.