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-cylinder
- some screws for mounting
- a strong cord

Notes:
If the impellerholder isn't used to lead on the left side of the door, you can mirror it in your slicer-program.

UPDATE:
2016-11-05: Function Report: Now that I have this thing some days working, I have to say it works perfect. The cord never left its guidance and the door shuts like it should.