Anyone who has built a large crane understands that treading the string to additional pulleys (like below) increases lifting capacity, but it is a pain in the rear end to do. Playing around with my crane this weekend resulted in the string coming off the pulleys.....so I am re-threading. Pain. Big pain. However, I found a video that is helping me out. Using some putty and rubber bands helps.
Fast forward to the end of the video to speed things up. approx. to the 7 minute mark