MPCNC w/laser for PCB isolation etch

Hello, just wanted to share what I’m working on, maybe someone has already done something similar, and could offer some advice.

I have added a 2w laser module to my MPCNC build. Using modified firmare for pin44 fan output.

Now I’m trying to use it to make custom PCB. The idea is one I’ve read here about (spray painting copper PCB, isolate traces then etc.).

Toolchain I’m experimenting on:

EAGLE -> PCB-Gcode plugin with custom settings (

I have modified one of the default postprocessor files (attached) so that:

-instead of Z high/Z up it sends an M106 Szup where nn is minimum power (0)

-instead of Z down (beginning of each trace) it sends and M106 Szdown where zdown is max power inputed into config window (see screenshot)


Sample gcode generated:


;Absolute Coordinates
M106 S1.0000
G00 X0.0000 Y0.0000 
M106 S0.0000 ;move to beginning of trace 
G00 X-12.2468 Y18.6781 
M106 S255.0000 ;start lasing
G01 X-12.3281 Y18.5968 F20.00 
G01 X-12.4237 Y18.5330 
G01 X-12.5298 Y18.4890
M106 S0.0000 ;end of trace


Before finding this out I was trying with image2gcode or manually tracing paths w.estlcam…this toolchain looks way faster.

Will update when trying an actual lase (can only simulate right know cause burnt diode…)


[attachment file=“pcb gcode settings.png”]



mpcnc-laser.pp_-1.txt (4.16 KB)