1.       Design a straight-ended helical torsion spring for a static load of 430 in-lb at a deflection of 55° with a safety factor of 2. Specify all parameters necessary to manufacture the spring. State all assumptions.

2.       Given the following data for a helical torsion spring, loaded in fatigue, find the spring index, unloaded coil diameter, minimum loaded coil diameter, and safety factor in fatigue. State all assumptions and sources of empirical data used. Deflection at assembly = 0.15 rev, working deflection = 0.35 rev, = 10 N-m/rev, Na = 25, 4.50 mm oil-tempered wire, unpeened.