I have a K40 laser that I successfully (mostly) converted to RAMPS using a version of MK4 Duo. I can operate it via LW4 and also save LW4 gcode files to SD card and use it standalone from the LCD panel. The issues I have are around the cutting speed. It seems a little arbitrary on my set up. Some jobs run fine but others cause the laser head to stop, with the laser on, for a second or so before continuing. I’ve not been able to track down the issue but suspect it may be caused by buffer overflows on the Mega 256 that I’m using. I have done the mods to increase the serial buffer to 256. The machine engraves fine from the Turnkey Tyranny Inkscape plugin (it didn’t until I did the serial buffer mod) but won’t engrave from LW4. I know LW4 supports GRBL and I have GRBL running fine on a couple of other machines. What I can’t seem to find anywhere, and I have been looking for a while, is a complete wiring diagram to connect a K40 to a GRBL based controller. Can anyone point me in the right direction? I have an old laptop sat around and intend to have that dedicated to the K40.