# US 10,500,785 B2 · Methods and apparatus for compensating for material distortion during additive manufacturing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,500,785 B2 - Document ID: US10500785B2 - Status: Granted - Kind: B2 - Application number: 15/435,431 - Filed: 2017-02-17 - Published: 2018-08-23 - Granted: 2019-12-10 - Earliest claimed: 2017-02-17 - Assignees: Thermwood Corporation - Applicants: Thermwood Corporation - Inventors: Kenneth J. Susnjara; Scott G. Vaal - Web page: https://patentgrep.com/patent/US10500785B2 ## CPC - B29C 64/106: using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material - B29C 64/194: during lay-up - B29C 64/393: for controlling or regulating additive manufacturing processes - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 50/02: for controlling or regulating additive manufacturing processes - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING ## Abstract Embodiments of the present disclosure are drawn to additive manufacturing methods. An exemplary method may include generating a tool path for forming a component via additive manufacturing, and assessing the tool path to identify a change in direction. The method may also include determining if the change in direction exceeds a predetermined angle, and adding a tangent arc to the tool path before the change in direction if the change in direction exceeds the predetermined angle. ## Claims ### Claim 1 An additive manufacturing method, comprising: generating a tool path including a first direction and a second direction; assessing the tool path to determine if a change in direction in the tool path exceeds a predetermined angle; moving a nozzle of an applicator head in the first direction, wherein the nozzle is configured to deposit a heated material, and wherein the applicator head includes a roller; diverting the nozzle along a tangent arc while depositing the heated material prior to a change in direction of the tool path to the second direction in order to compensate for the change in direction of the tool path; and engaging the deposited heated material with the roller while moving the nozzle in the second direction of the tool path to move at least a portion of the heated material deposited along the tangent arc toward the second direction, wherein the second direction is different than the first direction. ### Claim 2 (depends on 1) The method of claim 1, wherein the predetermined angle is within a range of approximately 40 degrees to approximately 90 degrees. ### Claim 3 (depends on 2) The method of claim 2, wherein the assessing occurs after generation of the tool path. ### Claim 4 (depends on 1) The method of claim 1, wherein the tangent arc is formed in a direction opposite to the change in direction of the tool path. ### Claim 5 (depends on 1) The method of claim 1, further comprising moving the roller behind the nozzle to compress the heated material deposited by the nozzle. ### Claim 6 (depends on 5) The method of claim 5, further comprising rotating the roller to a location opposite of the change in direction of the tool path after the diverting and before moving the nozzle in the second direction. ### Claim 7 (depends on 1) The method of claim 1, wherein the tangent arc is added to the tool path at a distance prior to the change in direction, and wherein the distance is determined based on the angle of the change in direction. ### Claim 8 (depends on 1) The method of claim 1, wherein a radius of curvature of the tangent arc is determined based on the angle of the change in direction. ### Claim 9 (depends on 1) The method of claim 1, wherein the heated material deposited along the tangent arc includes an outer surface, and wherein the roller moves the outer surface away from the tangent arc and toward the second direction. ### Claim 10 An additive manufacturing method, comprising: generating a tool path including a first direction and a second direction; moving a nozzle of an applicator head in the first direction, wherein the nozzle is configured to deposit a heated material, and wherein the applicator head includes a roller; diverting the nozzle along a tangent arc while depositing the heated material prior to a change in direction of the tool path to the second direction in order to compensate for the change in direction of the tool path; and engaging the deposited heated material with the roller while moving the nozzle in the second direction of the tool path to move at least a portion of the heated material deposited along the tangent arc toward the second direction, wherein the second direction is different than the first direction. ### Claim 11 (depends on 10) The method of claim 10, further comprising determining whether an angle of the change in direction of the tool path exceeds a predetermined angle within a range of approximately 40 degrees to approximately 90 degrees. ### Claim 12 (depends on 11) The method of claim 11, wherein the determining occurs after generation of the tool path. ### Claim 13 (depends on 10) The method of claim 10, wherein the tangent arc is formed in a direction opposite to the second direction of the tool path. ### Claim 14 (depends on 10) The method of claim 10, further comprising moving the roller behind the nozzle to compress the heated material deposited by the nozzle. ### Claim 15 (depends on 14) The method of claim 14, further comprising rotating the roller to a location opposite of the second direction of the tool path after the diverting and before moving the nozzle in the second direction. ### Claim 16 (depends on 10) The method of claim 10, wherein the tangent arc is added to the tool path at a distance prior to the second direction, and wherein the distance is determined based on an angle of the change in direction. ### Claim 17 (depends on 11) The method of claim 11, wherein a radius of curvature of the tangent arc is determined based on an angle of the change in direction. ### Claim 18 (depends on 10) The method of claim 10, wherein the heated material deposited along the tangent arc includes an outer surface that forms a bulge, and wherein the roller moves the outer surface toward the second direction.