After a run of bad luck with L-Cheapo units (kudos to their excellent and responsive support) I decided to get a much more expensive JTech Photonics unit. I bought the 2.8W laser, due to the smaller dot size (0.18mm) compared to the 3.5W, and the price difference.
The JTech unit is superbly built, their documentation is excellent and you can tell a lot of thought and planning went into the board design. At $335 I expected nothing less. There are very few players in this market, if you want a cheap laser you can buy the components off ebay and build it yourself. Be warned though, blue diode are super sensitive to static discharge and it’s really easy to destroy a diode just by holding it wrong.
I mounted the laser board next to the Azteeg X5 that is driving the engraver, hooked up the power, connected the TTL line to the Azteeg fan PWM output, and it works.
Here is one of the first cuts I made:
I still have a lot of issues to solve, I need to wire the cooling on the laser diode, which will considerably extend it’s lifespan and also allow me to drive it with a bit more current.
The software toolchain is also a major headache, the vast majority of free software for converting vector to gcode are inkscape plugins, none of which seem to work reliably (or at all). I’m currently experimenting with CamBam, but this also only kinda works, since it was not designed for laser cutters. You have to use post-processing on the gcode to make it suitable for a laser cutter. More on the software in an upcoming blog post (Part 4).