Automatic Door-closer (mechanical) v2

thingiverse

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 hinges. Disable the door handle. * Cats (optional) The axis should press-fit in the 608 bearing, which should press-fit in the pulley. (you probably need to push a bit hard) The lid is optional and just to make it look nicer. Cat pulling a door open: https://www.youtube.com/watch?v=exf7rj-6tU0 Cat pushing a door open: https://www.youtube.com/watch?v=edDsoldNQ64 Fully open: https://www.youtube.com/watch?v=uGhsFahRczU