# US 11,077,606 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 11,077,606 B2 - Document ID: US11077606B2 - Status: Granted - Kind: B2 - Application number: 17/067,376 - Filed: 2020-10-09 - Published: 2021-01-28 - Granted: 2021-08-03 - Earliest claimed: 2017-02-17 - Assignees: Thermwood Corporation - Applicants: Thermwood Corporation - Inventors: Kenneth J. Susnjara; Scott G. Vaal - Web page: https://patentgrep.com/patent/US11077606B2 ## 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 apparatus, comprising: an extruder configured to receive and heat a material; an applicator head downstream of the extruder, the applicator head including an opening configured to deposit the heated material; a roller; and a control system configured to control a position of the opening and the roller, the control system being programmed to: generate a tool path including a first portion and a second portion, the tool path including an outward diversion with respect to the first portion; cause the opening and the roller to move according to the first portion of the tool path while heated material is deposited from the opening; cause the opening to move according to the outward diversion while depositing the heated material prior to the second portion of the tool path; and cause the roller to engage the heated material to move at least a portion of the heated material deposited along the outward diversion toward the second portion, wherein the second portion and the first portion extend in different directions. ### Claim 2 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is further programmed to add the outward diversion to the tool path after generating the tool path including the first portion and the second portion. ### Claim 3 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the outward diversion has a shape of an outward bulge with respect to the first portion. ### Claim 4 (depends on 3) The additive manufacturing additive manufacturing apparatus of claim 3, wherein the outward bulge is positioned between the first portion and the second portion. ### Claim 5 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is further programmed to cause the roller to be positioned in alignment with the outward diversion and out of alignment with the first portion before the roller moves according to the second portion. ### Claim 6 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is further programmed to cause the roller to be positioned in alignment with the outward diversion such that a central portion of the roller overlaps a portion of the outward diversion having a largest deviation with respect to the first portion. ### Claim 7 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is further programmed to determine a location of the outward diversion based on an angle formed by the first portion and the second portion. ### Claim 8 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is further programmed to determine a shape of the outward diversion based on an angle of a change in direction formed by the first portion and the second portion. ### Claim 9 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the outward diversion connects the first portion of the tool path and the second portion of the tool path. ### Claim 10 (depends on 9) The additive manufacturing apparatus of claim 9, wherein the outward diversion includes a portion that diverts away from the first portion and away from the second portion. ### Claim 11 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the control system is configured to automatically add the outward diversion to the tool path based on a change in direction defined by the first portion and the second portion. ### Claim 12 An additive manufacturing apparatus, comprising: an extruder configured to receive and heat a material; an applicator head downstream of the extruder; an opening configured to deposit the heated material; a roller supported on the applicator head; and a control system configured to control a position of the opening and the roller, the control system being programmed to: generate a tool path including a first portion and a second portion; add an outward bulge to the tool path at an end of the first portion; cause the opening to move according to the first portion of the tool path while depositing material, cause the opening to divert according to the outward bulge while depositing the material, before the opening moves according to the second portion; and cause the roller to engage the deposited material to move at least a portion of the material deposited along the outward bulge toward the second portion, wherein the second portion and the first portion extend in different directions. ### Claim 13 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the control system is further programmed to add the outward bulge to the tool path after generating the first portion and the second portion of the tool path. ### Claim 14 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the outward bulge is formed in a direction opposite to the second portion of the tool path. ### Claim 15 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the control system is further programmed to cause the roller to move away from the first portion and the outward bulge before causing the roller to move according to the second portion. ### Claim 16 (depends on 15) The additive manufacturing apparatus of claim 15, wherein the control system is further programmed to cause the roller to rotate to a location opposite to the second portion before causing the opening to move along the second portion. ### Claim 17 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the control system is further programmed to determine a location of the outward bulge based on an angle formed by the first portion of the tool path and the second portion of the tool path. ### Claim 18 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the outward bulge connects the first portion of the tool path and the second portion of the tool path. ### Claim 19 (depends on 12) The additive manufacturing apparatus of claim 12, wherein the control system is configured to automatically add the outward bulge to the tool path based on a change in direction defined by the first portion and the second portion.