Using the WHEEL SUPPORT assembly (Figure 20.49) on page 994, sketch or draw a two-view drawing of the BASE. Dimension the drawing using the following geometric tolerance information:
a. Make all dimensions basic except for the size dimension of the 4 holes. Delete the 1.00 and 2.50 dimensions.
b. Identify the top surface of the part datum feature A. Control this surface with a fl atness tolerance of .005.
c. For this exercise change the four holes from threaded to through holes with a limit tolerance of .500-.510. Position the holes within .010 cylindrical tolerance zones at maximum material condition relative to datum feature A. Sometimes it is necessary to use a pattern of holes to establish a datum reference frame. Identify the hole as datum feature B by attaching the datum feature symbol to the bottom of the position feature control frame or to the shoulder of the leader for the size dimension of the holes.
d. Apply a profile of a surface tolerance all around of .005 relative to primary datum feature A and secondary datum feature B at maximum material condition. In the adjacent view, apply a profi le of a surface tolerance of .005 relative to datum feature A to the surface parallel to datum feature A.
