Hi all, I am trying to calculate the torque required by the motor to rotate a disk at a constant speed. Specs are as follows: 1. Disk radius =80mm 2. Disk Thickness =2 mm 3. Disk Weight =50gm 4. Constant speed= 3000rpm(CONSTANT) 5. Motor friction torque= 1mNm 6. Disk position parallel to ground. My question are as following: 1 Other than motor friction torque what are the other torque to be considered to calculate the total torque required to maintain the constant speed? 2. Dose the weight of the disk come in picture to calculate the torque? if yes what is the equation? If possible please provide the equations.