I built a zip line that is about 400 feet long and starts at about 35 feet elevation at a tree house going to a pole at the same elevation. I didn't want any danger of collision with the end of the line so it is gravity controlled and you zip about 80 percent of the way to the pole and then return and finally stop at the center of the line about 10 feet off the ground and dismount on a step ladder.It works very well but it is difficult to remove the zip pulley every time to return it to the start so I have a fishibg reel return line but it is also cumbersome. This forum seems to have a broad experience base and what I think would be ideal is a remote controlled powered pulley that I can send down the line to retrieve the harness back to the start. I think it would climb the cable as the incline is quite shallow when it is empty. Any ideas?