You're right .. I have been working on it and I got stuck a bit at converting the turning moment of the screw... into the horizontal Force acting on the on the sides of the ''scissor jack'' which will then raise it.
I worked out the turning moment of the thread while turning to be 2036N
and...
I have the same problem. I need to design a jack that lifts 10,000N of force, with a force applied by hand of 180N (turning the jack handle ) ... and I need to lift it by a height of 0.275m
where do I start ?