Setting Up The Printer
After you have set up OctoPrint on the Raspberry Pi, connect the Ultimaker 2 Extended to the Raspberry Pi via USB.
Make sure the Discov3ry is connected to the Ultimaker 2 via the E1 port in the main board under the printer.
In order to get the Ultimaker 2 Extended and Discov3ry paste extruder ready to print, the tube from the Discov3ry to the nozzle must be primed. This means that the Discov3ry must take time to push edible material all the way through to the nozzle. This is done by printing with modified CAD models repeatedly until the material is pushed through the tube and there is a consistent flow rate out of the nozzle. There is a modified gcode file called primer.gcode that runs for about 15 minutes - similar to the amount of time it takes to prime the tube with material. You can also run any gcode file from the models folder multiple times to achieve the same effect.