A Simple But Usefull and Ecological Door Closer From a Pc Hard Disk

here is a simple way to make a door closer made from a damaged hard disk sorry 4 the mess in the video

the video explins all the idea,by means of the wheight of a single damaged hard disk from a pc (originally i thought that i ned 2 ,but i see that its too heavy)and a fishing line, the door closes comlpletlywhen you pass it...i hope to finish this instructable later but i like to share the idea. in this photo i show the metod i use to attach the hard drive to the cord,a single thick wire