I have the X-Carve w/ X-Controller hooked up to my Macbook running Easel.
I’d like to sleep at some point in my life and thus need to pause some extra long cuts. There are also times when I need to stop a job in the middle of the day to go get some work done. 
So, what are the steps to properly pause and leave a project where I can come back and pick up where I left off?
Can I just leave the X-Controller powered on but unhook the USB from my Mac?
I’ve never paused myself but I used the forum search feature and found all these people that have:
https://discuss.inventables.com/search?q=pause%20with%20easel
No. That is bad. Unplugging the USB will reset GRBL on the next connection and you lose progress.
Two options:
Read my post here: Automatic 3-axis in Easel - Yes! it's possible
I also run with a Mac. Using @CharleyThomas Tri-quetra 3-axis touch plate, you can establish your XYZ zero point. Since my solution sets your zero point to a permanent(until changed) location, you can completely power down your entire system, then resume the next day.
To be 100% sure you’ll have no problems resuming you need the motors to remain powered on. But that is a bit of a risk since they generate most heat when idle. Going to sleep with motors powered on could potentially be dangerous if your current pots aren’t tuned properly.
Just a fyi. The alternative is powering down for the night but that will give you issues with a shifting zero probably…
Also, I’ve had my USB connection time out after a fe hours of inactivity so even with motors powered on, I still had to restart the damn job.
I would just register the corner using a zero plate then when I need to sleep stop the unit and not worry about anything then restart it in the morning Paying attention to where I left off and tell the system to continue there.
I am not sure if you can do that in Easel as I am using Mach3 now.
did a forum search and found this:
AllenMassey
You can edit the gcode and delete the lines that have run. Reposition the spindle at the original zero and run the remaining gcode. I have tried this before with mixed success.
I managed to save one project. But I think I could have just restarted from scratch quicker.
I did not know that, thanks! But it makes sense, the controller is passing current to hold the motors steady.
Didn’t I read an option about a setting to disable the hold feature?
You could try changing $1 to not be 255 which should disable them after X number of idle time, per GRBL.
$1 - Step idle delay, milliseconds
Every time your steppers complete a motion and come to a stop, Grbl will delay disabling the steppers by this value. OR, you can always keep your axes enabled (powered so as to hold position) by setting this value to the maximum 255 milliseconds. Again, just to repeat, you can keep all axes always enabled by setting $1=255.
The stepper idle lock time is the time length Grbl will keep the steppers locked before disabling. Depending on the system, you can set this to zero and disable it. On others, you may need 25-50 milliseconds to make sure your axes come to a complete stop before disabling. This is to help account for machine motors that do not like to be left on for long periods of time without doing something. Also, keep in mind that some stepper drivers don’t remember which micro step they stopped on, so when you re-enable, you may witness some ‘lost’ steps due to this. In this case, just keep your steppers enabled via $1=255.
Once you find your zero point, and as long as you ‘homed’ your machine first, you can issue a G28.1 or G30.1 to set a permanent ‘park’ location. You can then power down the machine entirely, turn it on the next day and, after you home again at startup, you could then issue a G28 or G30 to return the machine to the exact same zero point with 100% accuracy.
All of this is doable inside Easel. As my first post pointed out, (link above), you can automatically locate the XYZ zero inside Easel. The process I use sets the G28.1 as the final step. I use this workflow all the time now.
Don’t forget to check your computer ‘sleep’ settings!
maybe try it on a 5-minute carve midway before committing to a 2-day job 
What happens if the computer reboots because of an update or something?
The Windows updates can be paused for up to 7 days at a time within the update settings IF you’re concerned about auto reboots.
Personally I’d note what line of gcode it’s on, power the machine off and then back on in the AM, edit the gcode to remove the completed portion, and simply re-home, and re-use the prior zeros and run the rest from there and not leave the machine paused overnight, but that’s just me…
