I'm working on converting a cheap toy claw/crane machine into a shoddy Arduino-based CNC platform. I have only a vague idea what I'm doing. I'm mostly "winging it".
I'm using the Pixy computer vision module to track an LED mounted on top of the crane gantry, since the motors used are standard brushed DC motors with no sensors. This seemed like it would be easier than securely mounting rotary encoders on the crane gears.
This uses the Adafruit MotorShield and the Pixy, in additon to an Arduino Uno. A parts list will be posted later, possibly including sourcing links.