Inspired by a post at Instructables, and by the need of a device capable of engraving at creations made out of wood, we decided to build a cheap laser engraver.
It consists of parts from two old DVD-players, two EasyDrive stepper motor controller, a laser diode from eBay, a constant current regulator and a motherboard binding all the stuff together.
The PC-side software consist of about 50 line Python code. We use Python Imaging Library to load the pictures, and PySerial to communicate with the device.
Engraving time is now linearly dependent upon the pixel value, but we will look into creating a better relationship between laser time and amount engraved.