Elevator Design - Rack and Pinion Cascaded - 772

[Ether]

Originally Posted by akoscielski3

First off I never mentioned putting constant force springs on the elevator to eliminate almost all of the weight.

A loaded spring provides an extra source of power and changes the calculations.

the 28lbs included the outside rail, which is not being lifted at all

If the center of mass of a 28-lb assembly changes from 31" to 57" (a difference of 26"), it doesn't matter what parts move and what parts don't: it still takes 28*(26/12) foot-pounds of work. If you lift the whole assembly 26", or if you only lift half the assembly 52", it's still the same amount of work.

the mass that is being moved would be almost 0, if not positive from the springs.

The springs don't make the mass zero. They just balance the load and provide an additional source of power. The mass still has inertia.