Additive manufacturing system having interchangeable nozzle tips

1. An additive manufacturing system, comprising:

a moveable support;

a matrix reservoir operatively connected to an end of the moveable support;

a multi-channel nozzle module having a first tip with a rectangular orifice, and a first arrangement of cure enhancers located around the first tip;

a single-channel nozzle module having a second tip with a circular orifice, and a second arrangement of cure enhancers located around the second tip;

a tip changer mechanically connected to the multi-channel and single-channel nozzle modules; and

a controller in communication with the tip changer, the moveable support, and the first and second arrangements of cure enhancers, the controller being configured to:

receive specifications for a structure to be manufactured by the additive manufacturing system; and

selectively coordinate operation of the tip changer, the moveable support and the first and second arrangements of cure enhancers based on the specifications.

2. The additive manufacturing system of claim 1 , wherein:

the first and second tips have an axial direction of discharge; and

the tip changer has a pivot axis that is aligned with the axial direction of discharge to selectively move one of the first and second tips toward a discharge end the matrix reservoir to fluidly connect the one of the first and second tips with the matrix reservoir.

3. The additive manufacturing system of claim 2 , further including an actuator mechanically connected to the tip changer and selectively actuated by the controller to cause pivoting of the tip changer.

4. The additive manufacturing system of claim 2 , further including a seal located at the discharge end of the matrix reservoir and configured to engage only one of the multi-channel and single-channel nozzles at a time, wherein a non-engaged one of the multi-channel and single-channels nozzles is isolated from the matrix reservoir.

5. The additive manufacturing system of claim 1 , wherein:

the first arrangement of cure enhancers includes a plurality of cure enhancers arranged in a box around the rectangular orifice; and

the second arrangement of cure enhancers includes a plurality of cure enhancers arranged in a circle around the circular orifice.

6. A method of additively manufacturing a composite structure, the method comprising:

directing a single-tow reinforcement through a matrix reservoir to wet the single reinforcement;

discharging the single-tow reinforcement through a single-channel nozzle tip;

directing a multi-tow reinforcement through the matrix reservoir to wet the multi-tow reinforcement;

activating a tip changer to cause a multi-channel nozzle tip to replace the single-channel nozzle tip; and

discharging the multi-tow reinforcement through the multi-channel nozzle tip.

7. The method of claim 6 , further including exposing the first and second reinforcements to a cure energy during discharging to cause a matrix coating to cure.

8. The method of claim 6 , wherein the multi-tow reinforcement forms at least one of a ribbon and a sheet during discharge from the multi-channel nozzle tip.

9. The method of claim 6 , wherein activating the tip changer to cause the multi-channel nozzle tip to replace the single-channel nozzle tip includes activating the tip changer to cause the single-channel nozzle tip to pivot away and isolate from the matrix reservoir, and the multi-channel nozzle tip to pivot into engagement and fluid communication with the matrix reservoir.

10. The method of claim 6 , wherein discharging the multi-tow reinforcement through the multi-channel nozzle tip includes discharging the multi-tow reinforcement through a rectangular orifice.

11. The method of claim 6 , wherein discharging the single-tow reinforcement through the single-channel nozzle tip includes discharging the single-tow reinforcement through a circular orifice.

12. An additive manufacturing system, comprising:

a moveable support;

a matrix reservoir operatively connected to an end of the moveable support and configured to receive a liquid matrix;

a first nozzle tip having a discharge direction;

a second nozzle tip having the discharge direction; and

a tip changer mechanically connected between the first nozzle tip, the second nozzle tip, and the matrix reservoir, the tip changer configured to pivot the first and second nozzle tips about a pivot axis that is parallel with the discharge direction.

13. The additive manufacturing system of claim 12 , wherein the tip changer is pivotal to selectively connect only one of the first and second nozzle tips to a discharge end the matrix reservoir at a time.

14. The additive manufacturing system of claim 13 , further including an actuator mechanically connected to the tip changer and configured to cause pivoting of the tip changer.

15. The additive manufacturing system of claim 13 , further including a seal located at the discharge end of the matrix reservoir.

16. The additive manufacturing system of claim 12 , wherein the first nozzle tip includes a rectangular orifice.

17. The additive manufacturing system of claim 16 , wherein the second nozzle tip includes a circular orifice.

18. The additive manufacturing system of claim 12 , wherein:

the first nozzle tip is mounted within a first nozzle module having a first arrangement of cure enhancers configured to cure a first type of matrix-coated reinforcement; and

the second nozzle tip is mounted within a second nozzle module having a second arrangement of cure enhancers configured to cure a second type of matrix-coated reinforcement.

19. The additive manufacturing system of claim 18 , wherein:

the first type of matrix-coated reinforcement is at least one of a ribbon and a sheet; and

the second type of matrix-coated reinforcement is at least one of a single strand and a tow.

20. The additive manufacturing system of claim 12 , further including a valve configured to inhibit leakage of matrix from the matrix reservoir when the first and second nozzle tips are away from the matrix reservoir.