Hand-held three-dimensional drawing device

1. A three-dimensional (3D) drawing device comprising:

a housing configured to fit in a user's hand and shaped to allow manipulation of the housing like a pen, the housing having a first end, a second end, and a port configured for introduction of a strand of feed stock into an internal volume of the housing, the housing having at least one cooling port extending between the internal volume and an ambient atmosphere;

a first actuator and a second actuator each coupled to the housing and positioned to be actuated by the user's hand while holding the housing;

a motor disposed within the internal volume and controlled in response to operation of the first actuator and the second actuator;

a gear train operatively coupled with the motor to drive the gear train, disposed within the internal volume to receive the strand of feed stock, and configured to move the strand of feed stock when engaged with the gear train; and

a nozzle assembly disposed at the first end of the housing and at least partially within the housing, the nozzle assembly comprising an extruder, an exit nozzle, and a guide tube, the extruder having a heating element surrounded by an insulator, the guide tube extending between the gear train and the extruder, a first end of the guide tube positioned to receive the strand of feed stock from the gear train, a second end of the guide tube aligned with a chamber of the extruder such that the strand of feed stock is directed into the chamber, the extruder being disposed between the guide tube and the exit nozzle such that rotation of the motor causes the strand to be extruded out of the exit nozzle for permitting the user to draw in free space to form a three-dimensional object.

2. The 3D drawing device of claim 1 , further comprising a mounting tube having a first end and a second end, and wherein the second end of the guide tube extends into the first end of the mounting tube, and an end of the extruder opposite the nozzle extends into the second end of the mounting tube, the mounting tube holding the second end of the guide tube in alignment with the end of the extruder opposite the nozzle.

3. The 3D drawing device of claim 1 , wherein the housing comprises an upper housing and a lower housing, at least one of the upper housing and the lower housing comprising a cooling port of the at least one cooling port proximate to the nozzle.

4. The 3D drawing device of claim 3 , wherein each of the upper housing and the lower housing comprises the cooling port.

5. The 3D drawing device of claim 1 , wherein the first actuator and the second actuator are axially aligned and disposed on an outer surface of the housing between the first end and the second end.

6. The 3D drawing device of claim 1 , wherein actuation of the first actuator causes the motor to rotate in a first direction at a first motor rate to extrude the strand of feed stock out of the exit nozzle at a first extrusion rate, and actuation of the second actuator causes the motor to rotate in the first direction at a second motor rate to extrude the strand of feed stock out of the exit nozzle at a second extrusion rate that is greater than the first extrusion rate.

7. The 3D drawing device of claim 6 , wherein simultaneous actuation of the first and second actuators causes the motor to rotate in a second direction.

8. The 3D drawing device of claim 6 , further comprising a variable speed control mechanism to adjust one or more of the first extrusion rate and the second extrusion rate.

9. The 3D drawing device of claim 1 , wherein the heating element is positioned adjacent to the exit nozzle and configured to melt the strand of feed stock prior to extrusion through the exit nozzle.

10. The 3D drawing device of claim 1 , wherein the housing comprises at least one cooling port proximate to the exit nozzle, the cooling port in fluid communication with the internal volume.

11. The 3D drawing device of claim 1 , wherein the wherein the first actuator or the second actuator is configured to selectably cause the motor to rotate in at least a first direction that causes the strand of feed stock to be extruded out of the exit nozzle.

12. The 3D drawing device of claim 11 , wherein the first actuator or the second actuator is configured to selectably cause the motor to rotate in a second direction that is opposite the first direction.

13. The 3D drawing device of claim 12 , wherein the first and second actuators each comprise at least one button.

14. The 3D drawing device of claim 13 , the first actuator comprises a first button that causes the motor to rotate in the first direction at a first speed such that the strand of feed stock is extruded out of the exit nozzle at a first extrusion rate; and wherein the second actuator comprises a second button that that causes the motor to rotate in the first direction at a second speed such that the strand of feed stock is extruded out of the exit nozzle at a second extrusion rate that is greater than the first rate, wherein simultaneous actuation of the first and second buttons causes the motor to rotate in the second direction.

15. The 3D drawing device of claim 1 , wherein:

the gear train comprises a final gear having teeth that engage the strand of feed stock such that rotation of the final gear causes the strand of feed stock to linearly move.

16. The 3D drawing device of claim 1 , further comprising a fan configured to provide a flow cooling air at the exit nozzle.

17. The 3D drawing device of claim 1 , wherein the housing comprises a length between the first end and the second end, the length being greater than a maximum transverse extent of the housing.

18. A three-dimensional (3D) drawing device comprising:

an elongate housing having an internal volume and a port that permits insertion of a strand of material into the internal volume;

a gear train disposed within the internal volume to receive and move the strand when engaged with the gear train;

a motor, disposed within the internal volume, operatively coupled with the gear train to drive motion of the strand;

at least one actuator coupled to the housing to actuate the motor to control a movement of the strand; and

a nozzle assembly disposed at a distal end of the housing and comprising an extruder and an exit nozzle, the extruder having a heating element for melting the strand, the extruder being disposed between the gear train and the exit nozzle such that rotation of the motor causes the strand to be melted and extruded out of the exit nozzle to permit the user to draw in free space to form a three-dimensional object.

19. The 3D drawing device of claim 18 , further comprising a guide tube disposed within the housing and extending between the gear train and the extruder, a first end of the guide tube positioned to receive the strand from the gear train, a second end of the guide tube aligned with a chamber of the extruder such that the strand is directed into the chamber.

20. The 3D drawing device of claim 18 , wherein the housing comprises at least one cooling port extending between the internal volume and an ambient atmosphere.