A three-stage gear box with twelve speeds is to be designed based on R10 series with minimum spindle speed of 125 rpm. The second stage consists of three speed steps. The electric motor is connected to the gear box through a belt drive and runs at 1440 rpm and transmits of 5 kW. Using standard spindle speeds, 1. Draw the structure and speed diagram for the arrangement. 2. Determine the ratio of the belt pulley diameters. 3. Draw the gear box layout. 4. Determine the number of teeth on each gear of the gear box.