bdring made this laser controller for his wooden nickel engraver project and wrote a post on his blog detailing its assembly:
Here are some details on the custom laser controller I made for the NickelBot, wooden nickel engraving machine.
I want to use Grbl to control the machine. Grbl has support for lasers that allows better power control during the engrave. It also has the Core XY support I need for the H-bot mechanism it uses. The only feature I needed that it did not have is a hobby servo output.
More details at Buildlog.Net blog.