Methods for additively manufacturing composite parts

A method of additively manufacturing a composite part, the method comprising:

• applying a photopolymer resin to a non-resin component while pushing a continuous flexible line through a delivery assembly using a feed mechanism, and wherein the continuous flexible line comprises the non-resin component and a photopolymer-resin component that comprises at least some of the photopolymer resin applied to the non-resin component;
• depositing, via the delivery assembly, a segment of the continuous flexible line along a print path;
• and
• delivering curing energy to at least a portion of the segment of the continuous flexible line deposited along the print path;
• and
• wherein:
• the delivery assembly comprises a delivery guide, through which the feed mechanism pushes the continuous flexible line toward the print path;
• the delivery assembly further comprises an upstream portion;
• the delivery guide and the upstream portion are located on opposite sides of the feed mechanism;
• the feed mechanism is configured to push the continuous flexible line through the delivery guide and to pull the continuous flexible line through the upstream portion of the delivery assembly;
• the upstream portion comprises a first inlet, configured to receive the non-resin component;
• the upstream portion comprises a second inlet, configured to receive the photopolymer resin, an upstream outlet, through which the continuous flexible line exits the upstream portion, and an upstream line passage, extending from the first inlet to the upstream outlet;
• the second inlet is in fluid communication with the upstream line passage;
• applying the photopolymer resin to the non-resin component while pushing the continuous flexible line through the delivery assembly comprises injecting the photopolymer resin into the upstream portion via the second inlet;
• applying the photopolymer resin to the non-resin component while pushing the continuous flexible line through the delivery assembly comprises metering a flow of the photopolymer resin to the upstream portion;
• metering the flow of the photopolymer resin comprises detecting a level of the photopolymer resin within the upstream line passage;
• metering the flow of the photopolymer resin to the upstream portion is controlled by a resin-metering system;
• the resin-metering system comprises a high-level sensor, positioned upstream from the second inlet and configured to detect when a level of the photopolymer resin is at or above an upper threshold level in the upstream line passage;
• and
• the resin-metering system is configured to reduce the flow of the photopolymer resin when the photopolymer resin is at or above the upper threshold level in the upstream line passage.