# US 10,766,244 B2 · Methods and apparatus for compensating for thermal expansion 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 10,766,244 B2 - Document ID: US10766244B2 - Status: Granted - Kind: B2 - Application number: 16/572,953 - Filed: 2019-09-17 - Published: 2020-01-09 - Granted: 2020-09-08 - Earliest claimed: 2017-06-29 - Assignees: Thermwood Corporation - Applicants: Thermwood Corporation - Inventors: Kenneth J. Susnjara - Web page: https://patentgrep.com/patent/US10766244B2 ## CPC - G01B 5/0014: {due to temperature (on machine tools B23Q11/0003)} - B26D 5/005: {Computer numerical control means} - B29C 33/3842: {Manufacturing moulds, e.g. shaping the mould surface by machining} - B29C 64/10: Processes of additive manufacturing - B29C 64/106: using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material - B29C 64/112: using individual droplets, e.g. from jetting heads - B29C 64/118: using filamentary material being melted, e.g. fused deposition modelling [FDM] - B29C 64/124: using layers of liquid which are selectively solidified - B29C 64/129: characterised by the energy source therefor, e.g. by global irradiation combined with a mask - B29C 64/135: the energy source being concentrated, e.g. scanning lasers or focused light sources - B29C 64/141: using only solid materials - B29C 64/147: using sheet material, e.g. laminated object manufacturing [LOM] or laminating sheet material precut to local cross sections of the 3D object - B29C 64/153: using layers of powder being selectively joined, e.g. by selective laser sintering or melting - B29C 64/165: using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber - B29C 64/188: involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control (surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00) - B29C 64/393: for controlling or regulating additive manufacturing processes - B29C 69/001: {a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts (for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence)} - B33Y 10/00: Processes of additive manufacturing - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - B33Y 40/20: Post-treatment, e.g. curing, coating or polishing - B33Y 50/02: for controlling or regulating additive manufacturing processes - B33Y 80/00: Products made by additive manufacturing - G01B 11/002: {for measuring two or more coordinates} - B29K 2105/12: of short lengths, e.g. chopped filaments, staple fibres or bristles - B29K 2995/0012: having particular thermal properties - B29L 2031/757: {Moulds, cores, dies} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04) - 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 - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract Embodiments of the present disclosure are drawn to additive manufacturing apparatus and methods. An exemplary additive manufacturing method may include forming a part using additive manufacturing. The method may also include bringing the part to a first temperature, measuring the part along at least three axes at the first temperature, bringing the part to a second temperature, different than the first temperature, and measuring the part along the at least three axes at the second temperature. The method may further include comparing the size of the part at the first and second temperatures to calculate a coefficient of thermal expansion, generating a tool path that compensates for the coefficient of thermal expansion, bringing the part to the first temperature, and trimming the part while the part is at the first temperature using the tool path. ## Claims ### Claim 1 An additive manufacturing apparatus, comprising: a printing gantry; a nozzle movable with the printing gantry and configured to extrude a thermoplastic material; a trimming gantry; and a controller configured to: receive first size information indicative of a first size of a part at a first temperature; receive second size information indicative of a second size of the part at a second temperature; calculate a difference between the first size and the second size; and cause the trimming gantry to trim the part based on the difference between the first size and the second size. ### Claim 2 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the controller is configured to modify a tool path for trimming the part based on the difference between the first size information and the second size information. ### Claim 3 (depends on 1) The additive manufacturing apparatus of claim 1, further including a touch probe or a scanner configured to provide the first size information and the second size information. ### Claim 4 (depends on 3) The additive manufacturing apparatus of claim 3, wherein the touch probe or the scanner is attached to the trimming gantry. ### Claim 5 (depends on 1) The additive manufacturing apparatus of claim 1, further including a motor, and wherein the controller is configured to adjust a scaling of the motor based on the difference between the first size and the second size. ### Claim 6 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the additive manufacturing apparatus is configured to monitor an ambient temperature and adjust a tool path of the trimming gantry based on the monitored temperature. ### Claim 7 (depends on 1) The additive manufacturing apparatus of claim 1, wherein the controller is configured to generate a tool path of the additive manufacturing apparatus to compensate for a coefficient of thermal expansion determined based on the difference between the first size and the second size. ### Claim 8 An additive manufacturing apparatus, comprising: a trimming device; and a controller configured to: receive first size information indicative of a first size of a part at a first temperature; receive second size information indicative of a second size of the part at a second temperature; calculate a difference between the first size and the second size; and modify a tool path for trimming the part with the trimming device based on the difference between the first size information and the second size information. ### Claim 9 (depends on 8) The additive manufacturing apparatus of claim 8, wherein the part is a tool or a mold. ### Claim 10 (depends on 8) The additive manufacturing apparatus of claim 8, wherein the second temperature is higher than an ambient temperature. ### Claim 11 (depends on 8) The additive manufacturing apparatus of claim 8, wherein the additive manufacturing apparatus is configured to monitor an ambient temperature and adjust the tool path of the trimming device based on the monitored temperature. ### Claim 12 (depends on 8) The additive manufacturing apparatus of claim 8, wherein the controller is configured to control the trimming device based on an amount of expansion of the part. ### Claim 13 (depends on 8) The additive manufacturing apparatus of claim 8, further including a touch probe or a scanner attached to the trimming device and configured to provide the first size information and the second size information. ### Claim 14 An additive manufacturing apparatus, comprising: a trimming device configured to trim deposited material forming a part; and a controller configured to: calculate an amount of expansion when the part is warmed; generate a tool path for trimming the part based on the calculated amount of expansion; and cause the trimming device to trim the part based on the calculated amount of expansion. ### Claim 15 (depends on 14) The additive manufacturing apparatus of claim 14, wherein the controller is configured to calculate the amount of expansion by: calculating a first amount of expansion of the part with respect to a first axis; and calculating a second amount of expansion of the part with respect to a second axis that is different from the first axis, wherein the first amount of expansion is different than the second amount of expansion. ### Claim 16 (depends on 15) The additive manufacturing apparatus of claim 15, wherein the controller is configured to calculate the first amount of expansion based on a size of the part at an ambient temperature and a size of the part at a temperature higher than the ambient temperature. ### Claim 17 (depends on 14) The additive manufacturing apparatus of claim 14, wherein the part is a tool or a mold. ### Claim 18 (depends on 14) The additive manufacturing apparatus of claim 14, wherein the additive manufacturing apparatus is a computer numeric controlled (CNC) machine. ### Claim 19 (depends on 18) The additive manufacturing apparatus of claim 18, wherein the controller is configured to modify a motion of the trimming device of the CNC machine based on the calculated amount of expansion. ### Claim 20 (depends on 14) The additive manufacturing apparatus of claim 14, further including a touch probe or a scanner attached to the trimming device and configured to determine a size of the part for calculating the amount of expansion.