# US 11,897,186 B2 · Method and system for rotational 3D printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,897,186 B2 - Document ID: US11897186B2 - Status: Granted - Kind: B2 - Application number: 16/840,514 - Filed: 2020-04-06 - Published: 2020-07-23 - Granted: 2024-02-13 - Earliest claimed: 2014-07-13 - Assignees: Stratasys, Inc. - Applicants: Stratasys Ltd. - Inventors: Guy Menchik; Andrew James Carlson; Kevin Ready Campion; Robert Earl Simon; Nathaniel Michael Peterson - Web page: https://patentgrep.com/patent/US11897186B2 ## CPC - B29C 64/112: using individual droplets, e.g. from jetting heads - B29C 64/171: specially adapted for manufacturing multiple 3D objects - B29C 64/20: Apparatus for additive manufacturing; Details thereof or accessories therefor - B29C 64/241: for rotary motion - B29C 64/245: Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) - B29C 64/314: Preparation - B29C 64/393: for controlling or regulating additive manufacturing processes - B33Y 10/00: Processes of additive manufacturing - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B41J 2/1752: {Mounting within the printer} - B33Y 50/02: for controlling or regulating additive manufacturing processes - Y02P 10/25: Process efficiency - 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 - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A system for three-dimensional printing is disclosed. The system comprises: a rotary tray configured to rotate about a vertical axis; a printing head, each having a plurality of separated nozzles; and a controller configured for controlling the inkjet printing head to dispense, during the rotation, droplets of building material in layers, such as to print a three-dimensional object on the tray. ## Claims ### Claim 1 A system for three-dimensional printing, comprising: a rotary tray configured to rotate about a vertical axis; a printing head, having a plurality of separated nozzles and being configured to reciprocally move relative to said tray along a radial direction; and a controller configured for: obtaining a radial position of the printing head, controlling said printing head to dispense, during said rotation, droplets of building material in layers, to print a three-dimensional object on said tray, and to vary a rotation speed of said tray responsively to the radial position of said printing head. ### Claim 2 (depends on 1) The system according to claim 1, further comprising a radiation source configured to irradiate said layers such that energy at different rates is delivered to locations that are at difference distances from a center of said tray. ### Claim 3 (depends on 2) The system according to claim 2, wherein said radiation source is configured to reciprocally move relative to said tray along a radial direction, non-simultaneously with said printing head. ### Claim 4 (depends on 1) The system according to claim 1, wherein different nozzles are at different distances from said axis and dispense said building material at different dispensing rates. ### Claim 5 (depends on 1) The system according to claim 1, comprising at least two printing heads, wherein for each printing head, said reciprocal motion along said radial direction is independent and at a different azimuthal angle. ### Claim 6 (depends on 1) The system according to claim 1, wherein said controller is configured to control said printing head to dispense said droplets such that an azimuthal distance between sequentially dispensed droplets varies as a function of a position of said printing head along said radial direction. ### Claim 7 (depends on 1) The system according to claim 1, wherein said controller is configured to access a computer readable medium storing a bitmap mask, and to obtain printing data pertaining to a shape of the object only for locations on said tray that are not masked by said bitmap mask. ### Claim 8 (depends on 1) The system of claim 1, wherein said controller is configured to increase said rotation speed when said printing head is relocated to be closer to said vertical axis, and reduce said rotation speed when said printing head is relocated to be farther from said vertical axis. ### Claim 9 A system for three-dimensional printing, comprising: a rotary tray configured to rotate about a vertical axis; an inkjet printing head, having a plurality of separated nozzles; a controller configured for controlling said inkjet printing head to dispense, during said rotation, droplets of building material in layers, to print a three-dimensional object on said tray; and a radiation source configured to irradiate said layers, wherein the controller is configured to control the radiation source such that energy at different rates is delivered to locations that are at difference distances from a center of said tray wherein a rate at which energy is delivered decreases with the distance from said axis. ### Claim 10 (depends on 9) The system according to claim 9, wherein different nozzles are at different distances from said axis and dispense said building material at different dispensing rates. ### Claim 11 (depends on 9) The system according to claim 9, comprising at least two inkjet printing heads, wherein for each printing head, said reciprocal motion along said radial direction is independent and at a different azimuthal angle. ### Claim 12 (depends on 11) The system according to claim 11, wherein said controller is configured to control at least one of said inkjet printing heads to dispense said droplets such that an azimuthal distance between sequentially dispensed droplets varies as a function of a position of said inkjet printing head along said radial direction. ### Claim 13 (depends on 12) The system of claim 12, wherein said variation of azimuthal distance is based on a probabilistic function of said position along said radial direction. ### Claim 14 (depends on 12) The system according to claim 12, wherein said controller is configured to execute interlaced dispensing of said droplets during at least one rotation of said tray. ### Claim 15 (depends on 14) The system according to claim 14, wherein an interlace level of said interlaced dispensing varies as a function of a position of said inkjet printing head along said radial direction. ### Claim 16 (depends on 9) The system according to claim 9, wherein said controller is configured to access a computer readable medium storing a bitmap mask, and to obtain printing data pertaining to a shape of the object only for locations on said tray that are not masked by said bitmap mask. ### Claim 17 (depends on 9) The system according to claim 9, further comprising a pre-heater element for heating said building material before entering said inkjet printing head. ### Claim 18 (depends on 17) The system according to claim 17, wherein said pre-heater element is spaced apart from said head, and is in fluid communication with said head via a conduit. ### Claim 19 (depends on 9) The system according to claim 9, wherein said radiation source is configured to reciprocally move relative to said tray along a radial direction, and wherein said inkjet printing head is also configured to reciprocally move relative to said tray along said radial direction, non-simultaneously with said radiation source.