ok, I'll chime in.... torque= foot pounds. Let out as much chain as you like. Connect a fish scale to the arm. start to pull in the chain with the fish scale. see how many pounds it takes to lift the chain. multiply the pounds by the lever arm, eg, 50 pounds force times a 18 inch arm (1.5 feet) equals 75 foot pounds....so that's what you need to move the chain.... a good place to start... all
winches have different co-efficients of friction...if you now "connect" a motor with those specs, the chain will rise....