Being a non-engineering type, I'm trying to calculate what power and torque I would need from a DC stepper motor to execute a particular task. I'm certain that my question will open me up to potential observations regarding my lack of knowledge in this field. That said, if your critical observations use humor to make the point, I will appreciate them for that. However, I do expect to gain some good knowledge from this group. Here goes nothing.
I am building a device that will be used to lift, and hold 200 pounds approximately 2 feet in elevation. The mechanical elements of this device are 100% the same as a standard worm-shaft driven, scissor jack for a motor vehicle.
Envision a letter "A" as the two arms on the top of the scissor, and the left arm is anchored to the substrate, and the right arm is attached to the threaded block that travels along the worm-shaft. As the worm-shaft is rotated, the threaded block will travel along its axis which will in-turn cause the "A" to get taller and skinnier. This achieves the lift needed for the device.
In order to achieve the required power and torque to lift and hold 200 lbs without having to manually turn the worm-shaft (as one would when jacking up a car), should I couple the motor to the worm shaft concentrically, or use one gear on the motor shaft, and one on the worm-shaft?
Depending on the direct-couple method, or the gear ratio method, how do I determine the power and torque of the motor?
I really appreciate any help I can get with this challenge.