Chapter 7: Selecting Features
- On the Top plane, open a new sketch and draw a horizontal construction line across
the cylinder, from the midpoint of one side to the midpoint of the other side. To
pick up the automatic relations for the midpoints more easily, it is recommended that
you orient the view, normal to the sketch, or use the Top view. It does not matter if you
make the relations to the top or bottom cylinder, because the midpoints of the sides are
in the same place when they are projected into the sketch plane.
- Next, draw an ellipse (Tools ➪ Sketch Tools ➪ Ellipse) centered at the midpoint of
the construction line and that measures .700 inches horizontally and 1.375 inches
vertically. You may want to assign a relation between the center of the ellipse and one of
the control points to prevent the ellipse from rotating and fully define the sketch Exit the
sketch when you are satisfied with the result.
- Show the sketch for the Bosses feature. (Click the plus icon next to the Bosses extrude
to show the sketch, and then right-click the sketch and select Show.)
- Create a plane parallel to the Top plane at the center of the larger circle. You can
access the Plane creation interface by choosing Insert ➪ Reference Geometry ➪ Plane. If
you pre-select the Top plane from the flyout FeatureManager and the center of the larger
sketch circle from the graphics window, the interface automatically creates the correct
plane. Click OK to create the plane. Rename this plane Top Boss Plane.
- Draw a second ellipse on the Top Boss Plane. Do not draw a construction line as you
did for the first ellipse; instead, you can just make the centerpoint of the second ellipse
directly on top of the first ellipse’s centerpoint. The dimensions should be 1.000 inch
horizontal by 1.750 inches vertical. Figure 7.66 shows the results up to this point.
FIGURE 7.66
The results up to Step 8
