I don’t know the hookup procedures for the laser (I don’t have one). I think the J Tech instructions are suggesting that you can use the variable spindle wires to get the PWM signal from the Arduino to the laser controller. I defer this question to someone that has the laser.
To use the multi-mode grbl you just have to load the .hex file into your Arduino. If you don’t know how to do that I can help with that. Be sure to read the Readme included with the release.
You would use the normal Inventables grbl settings for spindle work and a different set of grbl parameters for using the laser.
If you don’t want to “get under the hood” and you just want to get to the good stuff, you might consider getting PicSender. It’s only $24.95 for a license and it will handle many of the issues with switching between laser and spindle mode.
We could ask Jeff ( @picengravertoo ) if he would post a set of typical grbl parameters for laser work to get you started.
All other grbl settings for the Laser or Spindle Mode are the same, except the $30, $31 for the maximum & minimum PWM values & $32 for enabling/disabling the Laser Mode.
In the PicSender GRBL menu, the settings can be changed easy and saved for the different modes with two separate text files Spindle.txt & Laser.txt. Then, when switching modes, the settings will automatically change in Larry’s grbl 1.0c.
Here is my wiring setup coming from the stock controller
I use a 24volt cooling fan for better cooling and I had one laying around it is tied in to the relay for my dewalt. unless you are using the cooling setup from jtech
this is a photo from inventables I edited as my camera is lacking battery power
Ok Have done the hookup as indicated here and if I try and connect automatically as in xcarve machine setup I get a quick on off flash of the laser. (connected the yellow and black wires from arduino to the laser driver) If I try and use picsend with a sample file Laser won’t come on when running unless I put driver in CW. ???