A few plans and a bunch of ideas.
See what's cookin in the world of CNC.
This little mill works like a charm, it was built using Aluminum stock, Round bar stock, and hardware found at "HomeDepot".
The electronics can be procured for about $60 minus stepper motors and power supply.
The spindle is a "JobMate" rotary tool and can be connected to the driver/ breakout board..
A couple links for using Arduino as a DRO "Digital Readout" and "PWM" "Pulse Width Modulation" controller.
How Arduino connects to Mach-3 using "ModBUS".