The RepRap Snappy is a 3D Printer design that is intended to be almost entirely printed. You can find more information about the Snappy on the RepRap Wiki.
The Snappy github repository is here.
Want to contribute a 3D printed part to ours? We've got a spreadsheet indicating project progress here: https://docs.google.com/spreadsheets/d/1jwSLDXKn8Jsij83Uw-GTa3-WKPTkHxfuVk4eCaoVHxo/edit?usp=sharing -if you want to take a part on, just claim it on the spreadsheet, and then bring it in once it's done.