CNC draft sketch
The CNC machine under consideration is a light-duty one, that should cut wood or perspex with widths less than 6mm. For this reason the design is simplified as much as possible as the main objective of this exercise is to probe the concept before considering a more robust one.
The machine will be built from the scap wood and the metal parts (bearings etc.) will be bought from ebay. An arduino with a CNC shield will be used to drive the stepper motors.
Some components will be 3D printed or machined as necessary, preference will be given to 3D printing as parts can be reprinted.
My first sketch illustrating this idea is shown in the figure below: