A thirteen year old maker just uploaded a new Instructable detailing his second custom built 3D printer called The Edge. The well written walkthrough has a complete part list, including places to purchase them, and links to the STL files for the components that need to be 3D printer and laser cut. You can read the details of the build over on 3Dprint.com. More details on the Edge 2.0 and links to instructions on how you can build one of these 3d printers yourself can be found here: http://3dprint.com/57847/edge-2-0-3d...for-under-200/

Below is a picture of the Edge 2.0 along with it's extruder housing: