The first step to any conversion or upgrade project is to research if it has been done before. The MF70 is an accurate device and therefore very suitable for precision machining. The majority of the device is made of aluminium and therefore can be fairly easily worked with hand tools. I have previously built a 3D printer and so I am familiar with stepper motor control and I have access to a lathe and a small metal workshop. Since I will be upgrading the mill in several stages, I decided that a lower precision middle stage was the best way to get going on this project. By printing the interface parts I would be able to easily test and change the design without the difficulty of reworking a harder material like aluminium or brass. The bubblegum CNC project (http://www.thingiverse.com/thing:33799) has some great parts that gave me alot of the initial dimensions for the build.