sudo nano /etc/udev/rules.d/52-arduino.rules

paste in the following

SUBSYSTEMS=="usb",KERNEL=="ttyACM*",ATTRS{idVendor}=="16c0",ATTRS{idProduct}=="0483",SYMLINK+="USBIO%n",GROUP="dialout",MODE="0666"
#Arduino Uno Auto Tool Changer
#SUBSYSTEMS=="usb",KERNEL=="ttyACM*",ATTRS{idVendor}=="2341",ATTRS{idProduct}=="0043",SYMLINK+="zbot_atc",GROUP="dialout",MODE="0666"
#Arduino Nano Auto Tool Changer (CH340 Bus IC)
SUBSYSTEMS=="usb",KERNEL=="ttyUSB*",ATTRS{idVendor}=="1a86",ATTRS{idProduct}=="7523",SYMLINK+="zbot_atc",GROUP="dialout",MODE="0666"

save, and reboot.