Figure P12-1 shows the same paper machine that was analyzed in Problem 6-46 and in other problems from previous chapters. The paper rolls in Figure P12-1 are 0.9-m OD X 0.22-m ID X 3.23 m long and have a density of 984 kg/m³. The rolls are transferred from the machine conveyor (not shown) to the forklift truck by the V-linkage of the off-load station, which is rotated through 90° by an air cylinder. The paper then rolls onto the waiting forks of the truck. The machine makes 30 rolls per hour and runs 2 shifts. The V-links are rotated by the crank arm through a shaft that is 60-mm dia by 3.23 m long. A redesign of the V-link rotating mechanism is desired in order to introduce a gearset between the crank arm and the V-link shaft with a 2:1 ratio. This will reduce the required stroke of the air cylinder by 50% and improve its geometry. Design a suitable spur-gear set for this application for a 10-year life against surface failure. State all assumptions.