>> Mechanical Engineering
Design a four-dwell cam to move a follower of mass == 1.25 bl from 0 to 2.5 inches in 40°, dwell for 100°, fall 1.5 inches in 90°, dwell for 20°, fall 0.5 inches in 30°, dwell for 40°, fall 0.5 inches in 30°, and dwell for the remainder. The total cycle must take 15 sec. Choose suitable programs for rise and fall to minimize dynamic forces and torques. Size a return spring and specify its preload to maintain contact between cam and follower. Calculate and plot the dynamic force and torque. Assume damping of 0.18 times critical. Repeat for a form-closed cam. Compare the dynamic force, torque, and natural frequency for the form-closed design and the force-closed design.