An instructables on how to make an Arduino based mini CNC plotter from old DVD drives by Ardumotive_com:
For the X and Y axes we will use two stepper motors and rails from dvd/cd drives and for the Z axis we will use a small servo motor that moves the pen up and down. For the mounting base we will use a small piece of plexiglass.
You can easily attach a pen (or pencil) – irrespective of its thickness – on it. I tried to use an extension of cutting tool (e.g.Dremel) to engrave materials with no success. So this mini cnc can only be used as a small plotter and not as an engraver machine.
The Arduino-based circuit is using the ATmega328 microcontroller, two L293 motor driver ICs and an usb to serial module. You can easily make it with the Arduino uno board and an breadboard.
Check out the video after the break.