Hi All I have a K40 laser that I successfully (mostly) converted to RAMPS

Hi All

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.


Andy what board would you use for GRBL?

@Ariel_Yahni_UniKpty I’m not sure but willing to take advice. Would an Uno running the latest GRBL with the laser enhancements and a suitable shield suffice? My machine has an own design Z table so would need 3 stepper drivers.

Are you in a budget or want something proven to work?

@Ariel_Yahni_UniKpty a proven, documented solution would be great but I don’t want to spend unnecessarily I’m open to suggestions

Cohesion 3D smoothie based with grbl-lpc firmware will be my choice.
I have a ramps 1.4 running Grbl with a laser diode very well and a cnc with mks-sbase board both connect to lw4 less issues.

Personally I got fed up with the RAMPs board with similar issues and ripped it out and put in an Uno with a CNC Shield on it w/ GRBL 1.1. Works better.

@Michael_Audette hi Michael. That’s really what I’m after. I even went as far as trying to implement it on my machine but stalled on how to set up the laser to fire. I need two pins. One for laser enable and one for laser intensity ( PWM). I couldn’t seem to crack it. Googled loads of sites but couldn’t find a suitable wiring diagram