Abstract: A three-dimensional (3D) printer is disclosed. The 3D printer can print viscous material such as plastisol, polymer clay, melted sugar and melted chocolate. The 3D printer utilizes an extruder that can prevent dripping of viscous material from a nozzle. The 3D printer includes a control circuit for controlling the movement of the extruder and the air flow within a pneumatic system.

Abstract: A system for three-dimensional (3D) printing edible objects, the system including: a first 3D printer including: a first processor; one or more cartridges for storing ingredients used in printing a 3D printed edible object, a plurality of extruders for extruding the ingredients during printing of the 3D printed edible object and a plurality of relays coupled to the plurality of extruders. A first cartridge stores a first ingredient while a second cartridge stores a second ingredient that may be different from the first ingredient. A first extruder extrudes the first ingredient and a second extruder extrudes the second ingredient in a synchronized motion. A first subset of the plurality of relays is configured to control the first extruder and a second subset of the plurality of relays is configured to control the second extruder.