The Arduino/gShield and X-Controller, used to control your X-Carve, comes preloaded with the Grbl firmware. If you receive a new Arduino without Grbl, or accidentally erased Grbl on a preloaded Arduino by flashing the blink sketch, you will need to do a re-flash.
There are several ways to re-flash your Arduino, but we've had the most success by using the Arduino IDE. Head over to the Arduino downloads page and install the latest version. PC users should click on "Windows Installer" and Mac users should click on "MAC OS X."
Head over to the Inventables forked version of Grbl to grab the firmware with the default settings for the X-Carve. Download by clicking on the green "Clone or download" button, and then the "Download ZIP" button. Unzip the file using your operating system's built in software or the software of your choosing. Make sure you fully extract the files and remember where they are located on your computer, because you will need to access this folder in the next step.
To add the Grbl library to your Arduino IDE, open up the IDE and navigate to Sketch - Include Library - Add .ZIP Library...
Click into the un-zipped grbl-master folder and choose the grbl folder.
After clicking on the "Choose" button, you should receive a confirmation in the IDE saying "Library added to your libraries."
Before you upload the sketch, make sure you have your board plugged in and selected under Tools - Port - xxxxxx(Arduino Uno). For PC users, you can verify the Port by checking in your computer's Device Manager.
For those advanced users who have tweaked their Grbl settings, now would be the time to record your current settings. Depending on which version of Grbl you are coming from, re-flashing should not overwrite your $$ settings. Recording your settings is just a precaution.
Navigate to the grblUpload sketch under File - Examples - grbl - grblUpload.
Click on the arrow icon in the top lefthand corner of the window to upload.
Congrats! You've successfully re-flashed! Now make sure to go through the Easel Setup Walkthrough to configure your machine.