3d printing system utilizing a multi-material printing unit

A three-dimensional (3D) printing system comprising:

• a first material canister containing a first type of material from which a 3D object is to be created;
• a second material canister containing a second type of material that is to serve as a scaffold for the first type of material during creation of the 3D object;
• a first feed line;
• a second feed line;
• a first nozzle that (i) is connected via the first feed line to the first material canister and (ii) comprises:
• a first interior chamber that is fillable with the first type of material;
• a first bottom orifice for releasing the first type of material from the first interior chamber;
• and
• a first valve stem that is movable within the first interior chamber and operable to open or close the first bottom orifice;
• a second nozzle that (i) is connected via the second feed line to the second material canister and (ii) comprises:
• a second interior chamber that is fillable with the second type of material;
• a second bottom orifice for releasing the second type of material from the second interior chamber;
• and
• a second valve stem that is movable within the second interior chamber and operable to open or close the second bottom orifice;
• a printing unit comprising:
• a carriage body;
• a first dispensing unit that is configured to hold and actuate the first valve stem;
• a second dispensing unit that is configured to hold and actuate the second valve stem;
• a first dispensing-motion unit that is configured to move the first dispensing unit in a vertical direction relative to the carriage body;
• and
• a second dispensing-motion unit that is configured to move the second dispensing unit in the vertical direction relative to the carriage body;
• and
• a carriage motion system that is configured to move the carriage in a horizontal plane;
• a crucible;
• a furnace;
• and
• a computing system that is programmed to carry out functions comprising:
• controlling the printing unit to dispense materials from the first and second nozzles into the crucible on a layer-by-layer basis for a plurality of layers, wherein each respective layer of the plurality of layers comprises either or both of the first type of material or the second type of material;
• and
• controlling the furnace to heat the crucible.