Additive manufacturing apparatuses and methods

1. A method of building an object by additive manufacturing, the method comprising:

pre-heating a deposition region of a build chamber to a pre-heat temperature;

distributing a layer of build material on a build platform positioned within the build chamber with a recoat assembly moving in a coating direction;

depositing a layer of binder material on the layer of build material;

irradiating the layer of build material with an energy source coupled to the recoat assembly;

adjusting a position of the build platform such that a portion of build material and binder is within a curing region of the build chamber, wherein the curing region of the build chamber is below the deposition region of the build chamber;

heating the curing region of the build chamber to a curing temperature, wherein the curing temperature is greater than the pre-heat temperature;

curing the binder within the curing region of the build chamber; and

distributing a new layer of build material above the portion of build material and binder on the build platform.

2. The method of claim 1 , wherein the layer of build material is irradiated with the energy source coupled to the recoat assembly before depositing the layer of binder material on the layer of build material.

3. The method of claim 1 , wherein the layer of build material is irradiated with the energy source coupled to the recoat assembly after depositing the layer of binder material on the layer of build material.

4. The method of claim 1 , wherein the layer of build material is irradiated with the energy source coupled to the recoat assembly both before and after depositing the layer of binder material on the layer of build material.

5. The method of claim 1 , wherein the heating and pre-heating are achieved with a plurality of heating elements positioned around the build chamber, below the build platform or both around the build chamber and below the build platform.

6. The method of claim 1 , wherein the distributing the layer of build material on the build platform positioned within the build chamber with the recoat assembly comprises:

moving the recoat assembly over the layer of build material with a recoat head actuator, the recoat head actuator comprising a recoat motion axis, whereby actuation of the recoat head actuator along the recoat motion axis in a first recoat direction causes the recoat assembly to move in the first recoat direction, and wherein the recoat assembly comprises a first roller and a second roller that is spaced apart from the first roller;

rotating the first roller of the recoat assembly in a counter-rotation direction, such that a bottom of the first roller moves in the first recoat direction; and

contacting the build material with the first roller of the recoat assembly, thereby fluidizing at least a portion of the build material.

7. The method of claim 6 , wherein the irradiating comprises irradiating, with a front energy source coupled to a front end of the recoat assembly, the layer of build material.

8. The method of claim 7 , further comprising irradiating, with a rear energy source positioned rearward of the front energy source, the new layer of build material.

9. The method of claim 8 , further comprising, subsequent to at least one of the irradiating with the front energy source and the irradiating with rear energy source, detecting a temperature of the irradiated build material with a temperature sensor.

10. The method of claim 9 , further comprising changing at least one parameter of the front energy source or the rear energy source based at least in part on the detected temperature.

11. The method of claim 6 , further comprising engaging a cleaning member with at least one of the first roller and the second roller.

12. The method of claim 1 , wherein the depositing the layer of binder material on the layer of build material comprises depositing binder material through select ones of a plurality of jet nozzles of a printing head onto the layer of build material as the printing head traverses a first pass trajectory along a longitudinal axis in a first direction.

13. The method of claim 12 , wherein the depositing the layer of binder material on the layer of build material further comprises:

indexing the printing head along a latitudinal axis to a second pass trajectory by an index distance; and

depositing binder material through select ones of the plurality of jet nozzles of the printing head as the printing head traverses the second pass trajectory along a longitudinal axis in a second direction opposite the first direction.

14. The method of claim 12 , further comprising passing the printing head over a binder purge bin to facilitate discharge of contaminants from the print head via backpressure.

15. The method of claim 14 , further comprising:

applying cleaning fluid to the printing head with a wet wipe member; and

removing cleaning fluid from the printing head with a dry wipe member.