This is a phenomenon experienced on many other FFF printers, where molten plastic continues to flow from the nozzle when the extruder has stopped. It is conventionally compensated for using a ‘retract’, where the filament is pulled back to ‘suck’ molten material away from the tip of the nozzle. Robox® uses a needle valve system to stop the extrusion as required at the tip of the nozzle, resulting in minimal ooze.