we are usign the van door motor, with a very unique way of pullign us up. we are suign 2 mechanisms, one is a ball screw($400 unit, thanks NOOK for the free screw
) and that drives up 1 section, that causes a system of cables to move, causign anuther part to extend, witch dose the same thign, causing another to extend. we are usign an electronic sprign pin system to hold it up after the power is cut(an idea to use a spinnign fly wheel to power it, but too heavy)
evryone seems to be usign winches.....not a winch or a chain on the whole thing