I was about to type in an expanded explanation of how PicsSender manages the grbl parameters, and thought that it might be some benefit beyond the thread I was in at the moment, so I decided to place the response here and link to it from the other thread.
For this thread I’m using screenshots from the 2.7.4 version of PicSender.
Here is the startup window, after I have homed my machine:
To move to the window that manages the grbl parameters press the gold “GRBL” button at the top right of the current window. That brings up the following window:
Notice that at the top middle of this window there is a selection for spindle or laser. At this time the selected device is “Laser”. This version of PicSender supports two multi-mode versions of grbl, my 1.0c version and the official 1.1f version.
PicSender works with two files on your disk drive that contain the settings to be used with the current PicSender session. They are “Laser.txt” and “Spindle.txt”. These are the default files that PicSender uses. You may also specify a different file to store/retrieve the settings from by using the “Save” and “Open” buttons (middle of the screen).
For grbl parameters that are the same for laser and spindle, you must set the parameter that you want to change in both files in order for the change to take effect for both the spindle and laser parameter sets.
There is a third location that stores the grbl parameters and that is in the Arduino/X-controller hardware. This is the version of the parameters that grbl works with to execute your G-code. It is the user’s responsibility to make sure that the correct parameter set is loaded into grbl before running a job on the machine.
However, once set up properly, PicSender will help you by placing the appropriate parameters set into grbl (based on the selection of “Laser” or "Spindle) when you start a PicSender session and when you change the device selection by pressing the “Spindle” or “Laser” button.
In order to display and/or change one or more grbl parameters, you press the green “GRBL Settings” button at the top center of the window. The display will change to something like this:
The panel on the right now contains the grbl parameters as they are in the Arduino/X-controller hardware and the left panel is the “edit” panel where you can change one or more settings to new values.
Make the changes that you want to make in the left panel and when you have them all done you will press the light green “Send” button to update the parameters in grbl (Arduino/X-controller hardware).
If you want to make the changes “persistent” you also press the violet “Save” button to save the new parameters in the Spindle.txt or Laser.txt files (you can also save to a different file name if you don’t want to change the default files, but you would need to use the “Open” button to retrieve those settings as PicSender loads either Spindle.txt or Laser.txt into grbl [Arduino/X-controller] when the program starts).
Remember, if you change a grbl parameter that affects both spindle and laser you must save a new default file for both the spindle device (Spindle.txt) and the laser device (Laser.txt) if you want the change to be persistent for both devices.
Press the gold “Return” button to return to the main screen.
It sounds very complicated, but once you have your machine tuned and the parameter files setup properly, it’s merely a quick one button press to change between spindle and laser.
Thanks go to Jeff and John for all their hard work to make this easy for the user.