This is one of the first engraving tests I have done on my K40 with a Mini Gerbil controller and an adjustable lens system by Ray Mckaig (https://tinyurl.com/vc2nwd5).
I used my programs (PicEngrave Pro and a development version of PicSender I am testing) to generate and send the gcode.
The image was engraved with variable laser power (gray scale mode), not dithered, using cherry wood, which seems to do very well IMO. Results with Baltic Birch ply have not been so good to date. More tests yet to do.