Ive designed this mill so that most of the parts that are hard to get or make can be 3D printed. Its design to be modular so you can easily change the size of the machine by changing either the sides or the front and back plates. Its accurate enough to cut and drill circuit boards, and small enough to fit in the boot of your car.
Full instructions at http://www.instructables.com/id/3D-printed-CNC-mill/
I used an UP printer using ABS plastic, and there is a common problem with most printers is that they print holes around 1-2% undersize, so the the holes for the bearings, bolts and nut has been drawn little oversize to compensate. I cant predict how they will fit with other types of printers or materials.
The sides and back are made with 2 layers of 3mm acrylic which can be laser cut if you have access to a laser cutter. Alternatively you could print the DXF files full size and cut and drill the material by hand.