Check it is wired correctly - if it is wired correctly please email us asking for a replacement and one will be sent out right away.
Check $4 = 1.
This is mostly due to either the motor being wired in an incorrect color order, or there is a loose wire connection.
This is a common error on a belt drive machine, as the motors have to be turning in opposite directions. Go back through section 6.1, and specifically look at the top right of the image regarding belt drive wiring.
Check $130, $131, & $132 are set to the correct value for your size machine. Make sure the CAM program is setup in millimeters. Make sure that work zero is set in a position which allows for enough travel on each axis to complete the job. Most CAM programs have a safe Z Height setting, so make sure there is also enough positive Z travel from work zero to accommodate this.
This is most likely because either a coupler or pulley is slipping on the motor shaft. Check screws are tight, and one of them is on the flat portion of the motor shaft.
Electrical interference is a common cause of this problem. Make sure the USB & router cable are outside the drag chains, and sleep/low power mode is turned off on the computer.
Carry out a long dummy run with a pen (i.e no router and no dust extraction) and see if the problem persists. If it still persists, try another computer.
Sometimes the $$ settings can change value, this usually happens if the machine is moved around by hand. Re-check all $$ values to make sure they are set correctly.
First, try another USB Cable. Then try another computer. The last thing to try is resetting the firmware on the controller. To do this download the Arduino IDE: Arduino Software
Connect the CNC xPro via USB and make sure Universal G-Code sender is closed. Open the Arduino IDE. In the Arduino IDE set:
Arduino/Genuino UnoAVRISP mkIIOpen Files > Examples > EEPROM > eeprom_clear and then click the upload button (Second button in from the left, is an arrow pointing to the right). If this gives an error please contact us. If you get the Done uploading message, follow these steps to upload GRBL: Compiling Grbl