Automatic Door-closer (mechanical)

This is a simple system to close your doors automaticly. It could be used indoors, in the garden or on a fence - feel free.Also it is fully mechanical and needs no electronics.Parts you need in addition:1 bearing 606ZZ (maybe I will add a impeller without a bearing - it should work too)Some weights (Sand, leadscrew, or something thats fit in the cylinder)some glue to close the weight-cylindersome screws for mountinga strong cord