M3 / M5 support for GRBL

[botboe]

I'm currently using grbl 0.9j, which gets detected correctly in the gui. When I try to laser a path extracted from a SVG-File, LaserWeb does not use M3 / M5 to enable or disable the laser but moves the Z-axis instead. This way my configuration won't work.

Is there a way to change this behavior?

Best regards Tobias

[Cinezaster]

I have the same configuration. I'm using M3/M5 to control the laser and S### to control the spindle pwm output for laser power. There are two types of controlling the lasers.

• via Z-axis: like you would engrave with a v-bit (lots of bigger lasers use this approach)
• spindle speed (laser diodes engravers like mr beam, Chinese $100 laser diode engravers)

Both should be an options when generating g-code.

Standard gcode cnc controllers stop the movement on a M3 or M5 command to compensate for the spindle getting up to the required speed. One would add a dwell G4 P## to pause and wait till the spindle is up to speed. For this reason they used the height of the z-axis with a very high acceleration setting to combine these three settings (x,y,laserpower). Using the spindle on/off and speed commands for controlling lasers would need a more custom gcode controller. These would allow you to set spindle pwm while keeping engraver in motion.

[ghost]

Thanks @Cinezaster - that may explain the dots we get at the end of raster lines on Marlin. So far we are running smoothly on Smoothie, LasaurGrbl - without that.

More importantly - I dont want to accomodate every possible configuration with If/Else anymore (:

So I am moving things like this into Machine Profiles: See https://github.com/openhardwarecoza/LaserWeb/issues/7#issuecomment-173659979

I'm closing this one for now - lets get #7 in place first

[ghost]

@Mad-Onion - see commit above - added M3/M5 for svg2gode