[Just_Build_It]

Unless the winch line and screw drive are paired to keep the door level going up and down I can see how your sketch would work.

I've watched the full sized trailer with the screw drive open and close 100 times by now. In the video there's 2 lines on each side one short and one long that are manually unhooked and hooked up for the 2 actions(open/close-up/down).

I've noticed on the full sized it looks like the hinged part of the door when it lays horizontal it locks into or lays vertical against the place for the screw drive to pull it up with the long lines attached to the screw drive(long lines for support) slide so it moves as a single unit up and down. When opening and closing, the short lines are attached at about the halfway height at the horizontal position. After that it looks like there's a seperation or its just the short lines that are hard fixed to the door frame so once the screw drive pushes the door up/down, in return like a teeter totter pulls the door updown and is shut/opened. Does that make any sense? My brain cells need a break.

I'm going to Lowe's tomorrow to pick out some cactiwith my wife for mothers day (picking out plants is our tradition) and I'm going to look for square tubing and threaded rod for the screw drive portion.