E3: My Camera Isn't Working OR My USB Stick Isn't Working

The Robo E3 has a place where you can toggle camera functionality with USB functionality. In order for the USB to work, you need to make sure the USB option is selected. Go into the on-printer menu and click into Tools/Settings/Camera (second page). Select Manual Mode and then either the USB icon or the camera icon, depending on which one you need at that moment.

If your USB stick is showing up, but the files are not, first make sure you have them in the correct file format. The 3D printer cannot read a .stl or .obj file. It must first be sliced using a slicing software such as RoboCloud or RoboPrint. If you have loaded a correct file type (.gx) and still not seeing the files, make sure the USB stick is formatted to FAT32 and the .gx files were sliced specifically for a Robo E3.