Work Planes, Features & Constraints: 1. Select the Work Plane feature tool, move the cursor to the rim of the base so that inside and outside edges are highlighted and click once on the bottom rim of the base. Grab one of the work plane corner handles and drag upward toward the top of the base. The Offset window will appear and enter a 0.125 in. offset. Page 11
2. Create a new sketch on the work plane. 3. With the Project Geometry tool, select and project the inside rim of the base onto the sketch plane. Page 12
4. Create a concentric circle by selecting the projected circle reference with the Offset tool. Drag the circle just inside the reference circle. 5. Use the General Dimension tool to set the offset between the circles at.10 in. Page 13
6. Exit the sketch and select Extrude from the Part Feature pallet. Select the.10 in. offset and select To Next from the Extents pull-down. This would be a good time to save your work. 7. Right-click on Work Plane1 in the Model browser. De-select Visibility to hide the work plane. Page 14
8. Right-click on Extrusion1 in the Model browser and select Edit Feature. 9. Select the More Tab and set a 1 Taper (draft) angle. Page 15
10. Zoom in, select Extrusion1, right-click and create a New Sketch on that plane. 11. Use the Project Geometry tool to project the X axis onto the sketch plane. Page 16
12. Draw a circle, centered on the projected axis, inside the ID of Extrusion1. 13. Give the circle a diameter of.25 in. Page 17
14. Right-click and select Create Constraint Tangent. 15. Select the circle you just drew and the ID of Extrusion1. 16. The Fillet tool won t work on these curved surfaces, so use the Three point arc tool and add fillets on both sides of the circle to the ID of Extrusion1. Make sure you start and end the arcs Page 18
intersecting the circles you should see a yellow snap dot appear when the cursor is intersecting a feature. Click one end point, then the other and finally a point on the arc to define it. Use the Tangent constraint tool to make the arcs tangent to the circles. You can see what constraints are in effect by right-clicking and selecting Show All Constraints. Page 19
18. Right-click again and select Hide All Constraints to cut down on the screen clutter. Get the Equal constraint tool. 19. With the Dimension tool, give one of the arcs a.125 in. radius. See how they stay equal? Page 20
20. Use the Trim tool to remove the inner arcs of the circle as shown: 21. Exit the Sketch, select the Extrude tool, select the boss profile and To Next Extent. Click OK. Page 21
22. Voila! The boss should be extruded from the flange of Extrusion1 up to the top of the part: 23. Create a new sketch on the flange surface and insert a Point, Hole Center on the center of the.25 in. diameter boss: Page 22
24. Exit the sketch and select the Hole feature tool. Check the Tapped option, set the depth to 0.5 in. and the thread to 8-32 UNC. Click OK. Page 23
25. Select the Circular Pattern feature tool. With Features selected in the Circular Pattern dialog, select Extrusion2 and Hole1 (the boss and tapped hole you just created) in the Model browser. Select Rotation Axis in the dialog, open the Origin folder in the Model dialog and click on the Y axis. Set Placement to 3 features distributed around 360 as illustrated and click OK. Page 24