Calculating electric motor's weight lifting ability knowing power. What else do I need to know?

Question

So, my company works with electric motors, and my boss wanted me to calculate how much weight could be lifted by a motor rated at 750W. I know that I can't just calculate the work done by it without any further specification of characteristics, but what I what to know is a couple of formulas that could get me there using measurable values, for example, i can measure current consumed when lifting a 10kg weight. Also, I'm open to suggestions, if you think there is an easier way to get where I want to, I am open to new ideas.

Answer 1

You would need to know the torque for which this motor is rated and the radius of the pulley(s)attached to the motor shaft and guiding the rope to the body to be lifted. We look at mechanical advantage of the pulleys.

Then we look at Work work required to move the weight a vertical distance and work the motor does in the process. A motor that can generate torques greater than the weight x distance will suffice.

1 HP = 756 Watts

1HP= 33,000 ft-lbs /minute

Torque = Force x radial distance to applied force on shaft....a 1 foot radius and 1 lb load is 1 foot-pound

You would need to measure the diameter of the pulley attached to the shaft and convert your measurement to applied torques for your loads and look at the motor rating for allowable torque.