Automatic Door-closer (mechanical) v2

This is a cat friendly door closing system for doors that are inside the house. The system is designed to be as smooth and un-intrusive as possible: You barely notice its there, but the doors will never stay open again.

I'm using this on 4 doors in my house now, for a couple of weeks. Its working excellent, and its saving a lot of heating costs.

This is inspired by the design of Lippifuss. This is a simpeler design, but its using two 608 bearings for extra smoothness.

What you need:
* Two 608ZZ bearings, preferably closed ones. (I used https://www.123-3d.nl/123-3D-Kogellager-608ZZ-DME00003-i20-t13131.html)
* Two printed sets of pulleys ( lid + pulley + axis stl files)
* One ballast tube. (either use ballast.stl or use white 16 mm electric wiring tube)
* Fish wire or rope.
* Screws
* Lead for your ballast tube (I used http://www.ballast-producten.nl/producten/ballast-lood/loodhagel/) You can also use sand, but you might need a bigger tube.
* Clean and lube your hi