Tabs are required to hold the component firm during the milling process. These tabs must be durable enough to support the weight of the part, as well as, resist the cutting forces applied by the milling machine. However, once the milling process is finished these tabs must be removed without damaging the part or obstructing its function. Begin by selecting the top view from the upper toolbar. The various viewing options are shown as cubes with highlighted faces to depict each surface. Next, click on the face of circular region shown in the top view. Figure 12 details the colored shading that occurs when the surface is selected.
Select the rectangle icon from the sketch menu and draw two rectangles each crossing the upper and lower area of the circular face, without touching the center hole. The size of each rectangle is not critical; each will be properly dimensioned using smart dimension. Be certain the rectangle edges extend past the perimeter of the part as illustrated in figure 13. Now establish a vertical center line through the two rectangles, and then line up their centers with the center of the part.
Create The Tab Profiles
Dimension the rectangles as shown in figure 14.
In the Features menu, locate the extruded boss/base option. Notice that the default extruded distance is 0.01 m =10 mm. which works well for this particular part. This value may be changed as necessary for other components. Under direction 1 in the Extrude menu, it is necessary to push the button that changes the normal direction of the rectangular extrusion. (This button has two arrows of different colors on it.) Otherwise the tabs will be located above the part and not attached as required. Additionally, click on selected contours and then highlight each of four sections to be extruded. Figure 15 shows this process. Select enter or the green check mark to see the part with the extruded tabs attached. The newly formed 3-D part is depicted in figure 16.
Create The 3-D Tabs