Hi I'm looking for some info and advice. I've looked across the Internet and forums looking at different formulas for working out the torque requirements for a motor but can't find anything that helps me. I have designed a small amusement ride. Please see pic below. The outer ring (yellow) needs to rotate at approx 35rpm. The mass of the ring and everything inside it is approx 750kg. The diameter of the ring is 3m How do I work out the torque required to spin the disc? And does adding in a gear box effect the torque needed at the motor? It's hard for me to select a suitable motor without knowing the power required. But let's say for example the motor is 1800rpm. For me to gear that down to 35rpm how does that effect the torque needed by the motor? Any help and advice appreciated.