We have just changed the pop door from opening with a hinge to sliding open. Eye screws to guide opening and closing using a rope from outside the pen. What type of rope works best for the sliding door method in a freezing cold winter area. Would a pulley be better than all eye screws? We can use a brick tied to the rope outside the pen to weight the pop door open but when we temporarily tested it we saw how it could accidentally open the door after we closed it. Anyone solve this problem without going into the pen and latching the door?