A simple DIY camera slider that uses a wind-up music box salvaged from an old toy. This could be used as a backup option in case one runs out of power. The wind-up mechanism delivers constant speed and is strong enough to move most DSLRs mounted on a heavy ball-head. The operating noise is really negligible. (The vintage Canon in the video was attached only for demonstration). The limitations of the wind-up mechanism are lack of speed & direction control.