Download the Gerber files here. I recommend Sunstone Circuits if you want to get it made.
L-Cheapo Mk2 and 3
Download the Gerber files here. I recommend 4pcb if you want to get it made.
The schematic is obvious, however -- the L-Cheapo only works properly if assembled according to the working drawings! Thermal conductivity is important. If you are building this on a prototyping board, be sure that the LM338 is properly soldered to the board in such a way that heat can transfer between it and the laser diode.
Do not use a single 0.7 ohm resistor instead of the eight 5.6 ohm resistors: having eight in parallel is important to let tolerances even out, and spread out the heat over a larger area.
Do not use a LM317 instead of a LM338, even if you can get a LM317 that can handle the current; the thermal coefficient is important.
Remember that the power plane in this circuit is NOT ground!
If you make this on a 2 layer board, the bottom copper should mirror the top copper (for thermal conductivity).
The design is provided for free, but on the explicit condition that you email email@example.com if you implement it; we can help, and we'd love a picture!
Thanks to Ruwan Janapriya for the diagram above!