Electric Winch - We made this using a small 12 volt motor and gearbox from RS components and added a bobbin for the rope - It can be operated remotely in both directions to pull ropes tight or lower keys etc. We now mainly use a number of different larger mains powered winches that are permanently bolted to the roof beams as this does everything the small wince can plus lift a person (note we modified them so they can be used with a remote control via our Logic controller) Below Katie K uses a winch to raise her elbows up behind her back to significantly increase the severity of her bondage.