For selecting motor... I need to calculate torque for motorised spool used to wind 5KM of fiber optic cable. Cable O.D. 4mm. The distance between flanges is 520mm. Flange O.D. 650mm. Application of spool is only reeling and unreeling. While unreeling will be done by manually. Assume empty spool weight 20 Kg. RPM=50 What will be torque and power rating?