US010556381B2
`
`a2) United States Patent
`US 10,556,381 B2
`(10) Patent No.:
`Feb. 11, 2020
`(45) Date of Patent:
`Kemperleet al.
`
`(54) THREE-DIMENSIONAL PRINTER WITH
`FORCE DETECTION
`
`(71) Applicant: MakerBot Industries, LLC, Brooklyn,
`NY (US)
`
`(72)
`
`Inventors: Aljosa Kemperle, Brooklyn, NY (US);
`Filipp Gelman, Staten Island, NY
`(US); Peter Joseph Schmehl,
`Brooklyn, NY (US)
`
`(73) Assignee: MakerBot Industries, LLC, Brooklyn,
`NY (US)
`
`Notice:
`
`Subject to any disclaimer, the termofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 1002 days.
`
`(21) Appl. No.: 14/922,267
`
`(22)
`
`Filed:
`
`Oct. 26, 2015
`
`(65)
`
`Prior Publication Data
`
`US 2016/0039150 Al
`
`Feb. 11, 2016
`
`Related U.S. Application Data
`
`48/265 (2019.02); B29C 48/266 (2019.02);
`B29C 2948/9258 (2019.02); B29C 2948/92704
`(2019.02);
`
`(Continued)
`(58) Field of Classification Search
`CPC..... B29C 43/08; B29C 43/58; B29C 43/5808;
`B29C 43/5816; B29C 43/5833; B29C
`43/5875; B29C 64/20; B29C 64/393;
`B33Y 40/00; B33Y 50/00; B33Y 50/02
`USPC cece 425/143, 170-171, 78, 344-345,
`700/197, 206; 141/71, 74, 78
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`§,303,141 A
`6,129,872 A
`
`4/1994 Batchelderet al.
`10/2000 Jang
`(Continued)
`
`OTHER PUBLICATIONS
`
`“Touch Sensor and Automated Calibration”, by Assargadon—http://
`forums.reprap.org/read.php? 11,8028, Jan. 4, 2008 , 14 pages.
`(Continued)
`
`Continuation of application No. 14/065,516, filed on
`Oct. 29, 2013, now Pat. No. 9,168,698.
`(Continued)
`
`Primary Examiner — Joseph S Del Sole
`Assistant Examiner — Thu Khanh T Nguyen
`(74) Attorney, Agent, or Firm — Strategic Patents, P.C.
`
`Int. Cl.
`B29C 41/22
`B29C 41/52
`
`(2006.01)
`(2006.01)
`(Continued)
`
`(52) U.S. Cl.
`CPC wee B29C 64/205 (2017.08); B29C 48/154
`(2019.02); B29C 48/92 (2019.02), B29C
`64/106 (2017.08); B29C 64/209 (2017.08);
`B29C 64/386 (2017.08); B29C 64/40
`(2017.08); B33Y 30/00 (2014.12): B33Y 50/02
`(2014.12); B29C 48/02 (2019.02); B29C
`
`(57)
`
`ABSTRACT
`
`An extruderorother tool head ofa three-dimensionalprinter
`is instrumented to detect contact force against the extruder,
`such as by a build platform or an object being fabricated.
`The tool head mayalso be instrumented to detect deflection
`forces and thelike acting on the tool that mightindicate an
`operating error. The resulting feedback data can be used in
`a variety of ways to control operation of the three-dimen-
`sional printer during fabrication or diagnostics.
`
`16 Claims, 5 Drawing Sheets
`
`(63)
`
`(51)
`
`
`
`110
`
`OTHER HARDWARE
`134
`
` CONTROLLER
`
`
`
`
`
`X-Y-Z POSITIONING ASSEMBLY108
`STEPPER MOTOR
`
`
`
`
`
`109
`
`130
`
`
`BUILD PLATFORM 102
`
`
`
`Shenzhen Tuozhu 1001
`
`1
`
`Shenzhen Tuozhu 1001
`
`

`

`US 10,556,381 B2
`Page 2
`
`Related U.S. Application Data
`
`(60) Provisional application No. 61/719,874,filed on Oct.
`29, 2012.
`
`(51)
`
`Int. Cl.
`B29C 64/205
`B29C 64/209
`B29C 48/92
`B29C 48/154
`B29C 64/106
`B29C 64/386
`B29C 64/40
`B33Y 30/00
`B33Y 50/02
`B3380/00
`B29C 48/02
`B29C 48/265
`B29C 48/25
`B33Y50/00
`B33Y 10/00
`B33Y40/00
`B33Y70/00
`B29K 101/12
`B29K 105/00
`
`(2006.0 NeNeeeeeeeeeeeeeeeeeeeeeaeae
`
`(2017.0
`(2017.0
`(2019.0
`(2019.0
`(2017.0
`(2017.0
`(2017.0
`(2015.0
`(2015.0
`(2015.0
`(2019.0
`(2019.0
`(2019.0
`(2015.0
`(2015.0
`(2020.0
`(2020.0
`(2006.0
`
`(52) U.S. Ch
`CPC ... B29K 2101/12 (2013.01); B29K 2105/0067
`(2013.01); B33Y 10/00 (2014.12); B33Y 40/00
`(2014.12); B33Y 50/00 (2014.12); B33Y 70/00
`(2014.12); B33¥ 80/00 (2014.12)
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`6.629,011 Bl
`7,625,198 B2
`7,939,003 B2*
`
`9/2003 Calderonet al.
`12/2009 Lipson etal.
`5/2011 Bonassar
`................ AGLL 27/36
`264/308
`
`2014/0117575 Al
`
`5/2014 Kemperle etal.
`
`OTHER PUBLICATIONS
`
`“HydraRaptor’, http://hydraraptor.blogspot.com/2011/04/auto-z-
`probe.html Apr. 4, 2011 , 12 pages.
`“Automated Bed Leveling With Our 3D Printer”, by Brian Benchoff—
`hitp://hackaday.com/2012/04/23/automated-bed-teveling-with-our-
`3d-printer’ Apr. 23, 2012 , 5 pages.
`USPTO,“U.S. Appl. No, 14/065,516, Non Final Office Action dated
`Apr. 9, 2015”, 12 pages.
`USPTO, “U.S. Appl. No. 14/065,516, Notice of Allowance dated
`Jul. 22, 2015”, 7 pages.
`
`* cited by examiner
`
`2
`
`

`

`U.S. Patent
`
`Feb. 11, 2020
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`Sheet 1 of 5
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`US 10,556,381 B2
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`

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`U.S. Patent
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`Feb. 11,2020
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`Sheet 2 of 5
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`US 10,556,381 B2
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`Fig.2
`
`4
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`

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`U.S. Patent
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`Feb. 11, 2020
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`Sheet 3 of 5
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`US 10,556,381 B2
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`U.S. Patent
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`Feb. 11,2020
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`Sheet 4 of 5
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`US 10,556,381 B2
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`U.S. Patent
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`Feb. 11, 2020
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`Sheet 5 of 5
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`US 10,556,381 B2
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`

`US 10,556,381 B2
`
`1
`THREE-DIMENSIONAL PRINTER WITH
`FORCE DETECTION
`
`
`
`RELATED APPLICATIONS
`
`This application is a continuation of U.S. patent applica-
`tion Ser. No. 14/065,516 filed Oct. 29, 2013 (nowUSS. Pat.
`No. 9,168,698), which claims the benefit of U.S. Pat. App.
`No. 61/719,874, filed Oct. 29, 2012, where the entirety of
`each is hereby incorporated byreference herein.
`
`BACKGROUND
`
`Three-dimensional printers can be used to fabricate vari-
`ous desired objects based on computer models of those
`objects. However, components of the three-dimensional
`printer may degrade with time—i.e., become dented,
`warped, misaligned, etc. These errors may disadvanta-
`geously affect the ability of the three-dimensionalprinter to
`accurately fabricate objects. There remains a need for pres-
`sure-sensing extruders and methods for using same.
`
`mH on
`
`SUMMARY
`
`35
`
`40
`
`45
`
`An extruder or other tool head of a three-dimensional
`printer is instrumented to detect contact force against the
`extruder, such as by a build platform or an object being
`fabricated. The tool head may also be instrumentedto detect
`deflection forces and the like acting on the tool that might
`indicate an operating error. The resulting feedback data can
`be used in a variety of ways to control operation of the
`three-dimensional printer during fabrication or diagnostics.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`
`
`The invention and the following detailed description of
`certain embodiments thereof may be understood byrefer-
`ence to the following figures:
`FIG. 1 is a block diagram of a three-dimensionalprinter.
`FIG. 2 showsa three-dimensionalprinter.
`FIG. 3 is a block diagram of a fabrication tool for use in
`a three-dimensional printer.
`FIG. 4 is a flowchart of a process for using an instru-
`mented fabrication tool.
`FIG. 5 showsa cross section of a leveling operation.
`FIG.6 is a flowchart of a process for fabricating an object.
`
`DETAILED DESCRIPTION
`
`All documents mentioned herein are hereby incorporated
`in their entirety by reference. References to items in the
`singular should be understood to include itemsin the plural,
`and vice versa, unless explicitly stated otherwise or clear
`from the text. Grammatical conjunctions are intended to
`express any and all disjunctive and conjunctive combina-
`tions of conjoined clauses, sentences, words, andthelike,
`unless otherwisestated or clear from the context. Thus the
`
`term “or” should generally be understood to mean “and/or”
`and so forth.
`
`The following description emphasizes three-dimensional
`printers using fused deposition modeling or similar tech-
`niques where a bead of material is extruded in a layered
`series of two dimensionalpatterns as “roads,” “paths” or the
`like to form a three-dimensional object from a digital model.
`It will be understood, however,
`that numerous additive
`fabrication techniques are known in the art including with-
`out limitation multijet printing, stereolithography, Digital
`
`2
`Light Processor (“DLP”) three-dimensionalprinting, selec-
`tive laser sintering, and so forth. Such techniques may
`benefit from the systems and methodsdescribed below, and
`all such printing technologies are intended to fall within the
`scopeof this disclosure, and within the scope of terms such
`as “printer”, “three-dimensional printer”, “fabrication sys-
`tem”, and so forth, unless a more specific meaning is
`explicitly provided or otherwise clear from the context.
`FIG. 1 is a block diagram of a three-dimensionalprinter.
`In general, the printer 100 mayinclude a build platform 102,
`an extruder 106, an x-y-z positioning assembly 108, and a
`controller 110 that cooperate to fabricate an object 112
`within a working volume 114 ofthe printer 100.
`The build platform 102 may include a surface 116 that is
`rigid and substantially planar. The surface 116 may provide
`a fixed, dimensionally and positionally stable platform on
`which to build the object 112. The build platform 102 may
`includea thermal element 130 that controls the temperature
`of the build platform 102 through one or more active devices
`132, suchasresistive elements that convert electrical current
`into heat, Peltier effect devices that can create a heating or
`cooling affect, or any other thermoelectric heating and/or
`cooling devices. The thermal element 130 maybe coupled in
`a communicating relationship with the controller 110 in
`order for the controller 110 to controllably impart heat to or
`removeheat fromthe surface 116 of the build platform 102.
`The extruder 106 may include a chamber 122 in an
`interior thereof to receive a build material. The build mate-
`rial may, for example, include acrylonitrile butadiene sty-
`rene (“ABS”), high-density polyethylene (“‘HDPL”), poly-
`lactic
`acid (“PLA”),
`or
`any other
`suitable plastic,
`thermoplastic, or other material that can usefully be extruded
`to form a three-dimensional object. The extruder 106 may
`include an extrusion tip 124 or other opening that includes
`an exit port with a circular, oval, slotted or other cross-
`sectional profile that extrudes build material in a desired
`cross-sectional shape.
`The extruder 106 may include a heater 126 (also referred
`to as a heating element) to melt thermoplastic or other
`meltable build materials within the chamber 122 for extru-
`sion through an extrusion tip 124 in liquid form. While
`illustrated in block form, it will be understood that the heater
`126 mayinclude, e.g., coils of resistive wire wrapped about
`the extruder 106, one or more heating blocks with resistive
`elements to heat the extruder 106 with applied current, an
`inductive heater, or any other arrangement of heating ele-
`ments suitable for creating heat within the chamber 122
`sufficient
`to melt the build material for extrusion. The
`
`extruder 106 may also or instead include a motor 128 orthe
`like to push the build material into the chamber 122 and/or
`through the extrusion tip 124.
`In general operation (and by way of example rather than
`limitation), a build material such as ABSplastic in filament
`form may be fed into the chamber 122 from a spool or the
`like by the motor 128, melted by the heater 126, and
`extruded from the extrusiontip 124. By controlling a rate of
`the motor 128, the temperature of the heater 126, and/or
`other process parameters, the build material may be extruded
`at a controlled volumetric rate. It will be understood that a
`variety of techniques mayalso or instead be employed to
`deliver build material at a controlled volumetric rate. which
`may depend upon the type of build material, the volumetric
`rate desired, and any other factors. All such techniques that
`might be suitably adapted to delivery of build material for
`fabrication ofa three-dimensional object are intended to fall
`within the scope of this disclosure.
`
`8
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`US 10,556,381 B2
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`m Oo
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`The x-y-z positioning assembly 108 may generally be
`adapted to three-dimensionallyposition the extruder 106 and
`the extrusion tip 124 within the working volume 114. Thus
`by controlling the volumetric rate of delivery for the build
`material andthe x, y, z position of the extrusiontip 124, the
`object 112 may befabricated in three dimensions bydepos-
`iting successive layers of material in two-dimensional pat-
`terns derived, for example, from cross-sections of a com-
`puter model or other computerized representation of the
`object 112. A variety of arrangements and techniques are
`known in the art to achieve controlled linear movement
`along one or more axes. The x-y-z positioning assembly 108
`may, for example, include a number of stepper motors 109
`to independently control a position of the extruder 106
`within the working volumealong each ofan x-axis, a y-axis,
`and a z-axis. More generally, the x-y-z positioning assembly
`108 may include withoutlimitation various combinations of
`stepper motors, encoded DC motors, gears, belts, pulleys,
`worm gears, threads, and so forth. For example,
`in one
`aspect the build platform 102 may be coupled to one or more
`threaded rods bya threaded nut so that the threaded rods can
`be rotated to provide z-axis positioning of the build platform
`102 relative to the extruder 124. This arrangement may
`advantageously simplify design and improve accuracy by
`permitting an x-y positioning mechanism for the extruder
`124 to be fixed relative to a build volume. Any such
`arrangement
`suitable
`for
`controllably positioning the
`extruder 106 within the working volume 114 maybe adapted
`to use with the printer 100 described herein.
`In general, this may include moving the extruder 106, or
`moving the build platform 102, or some combination of
`these. Thus it will be appreciated that any reference to
`moving an extruderrelative to a build platform, working
`volume, or object, is intended to include movement of the
`extruder or movement ofthe build platform,or both, unless
`a more specific meaning is explicitly provided or otherwise
`clear from the context. Still more generally, while an x, y, z
`coordinate system serves as a convenient basis for position-
`ing within three dimensions, any other coordinate system or
`combination of coordinate systems mayalso or instead be
`employed, such as a positional controller and assembly that
`operates according to cylindrical or spherical coordinates.
`The controller 110 may be electrically or otherwise
`coupled in a communicating relationship with the build
`platform 102, the x-y-z positioning assembly 108, and the
`other various components of the printer 100. In general, the
`controller 110 is operable to control the components of the
`printer 100, such as the build platform 102,
`the x-y-z
`positioning assembly 108, and any other components of the
`printer 100 described hereinto fabricate the object 112 from
`the build material. The controller 110 may include any
`combination ofsoftware and/or processing circuitry suitable
`for controlling the various components of the printer 100
`described herein including without limitation microproces-
`sors, microcontrollers, application-specific integrated cir-
`cuits, programmable gate arrays, and any otherdigital and/or
`analog components, as well as combinationsof the forego-
`ing, along with inputs and outputs for transceiving control
`signals, drive signals, power signals, sensor signals, and so
`forth. In one aspect, this may include circuitry directly and
`physically associated with the printer 100 such as an on-
`board processor. In another aspect, this may be a processor
`associated with a personal computer or other computing
`device coupled to the printer 100, e.g., through a wired or
`wireless connection. Similarly, various functions described
`herein maybe allocated between an on-board processor for
`the printer 100 and a separate computer. All such computing
`
`
`
`4
`devices and environments are intended to fall within the
`
`meaning of the term “controller” or “processor” as used
`herein, unless a different meaning is explicitly provided or
`otherwise clear from the context.
`
`A variety of additional sensors and other components may
`be usefully incorporated into the printer 100 described
`above. These other componentsare generically depicted as
`other hardware 134 in FIG. 1, for which the positioning and
`mechanical/electrical interconnections with other elements
`
`
`
`of the printer 100 will be readily understood and appreciated
`byone of ordinary skill in the art. The other hardware 134
`may include a temperature sensor positioned to sense a
`temperature of the surface of the build platform 102, the
`extruder 126, or any other system components. This may, for
`example, include a thermistor or the like embedded within
`or attached below the surface of the build platform 102. This
`mayalsoor instead include an infrared detectoror the like
`directed at the surface 116 of the build platform 102.
`In another aspect, the other hardware 134 may include a
`sensor to detect a presence of the object 112 at a predeter-
`mined location. This may include an optical detector
`arranged in a beam-breaking configuration to sense the
`presence of the object 112 at a predetermined location. This
`may also or instead include an imaging device and image
`processing circuitry to capture an image of the working
`volumeand to analyze the image to evaluate a position ofthe
`object 112. This sensor may be used for example to ensure
`that the object 112 is removed from the build platform 102
`prior to beginning a new build on the working surface 116.
`Thus the sensor maybe used to determine whether an object
`is present that should not be, or to detect when an objectis
`absent. The feedback from this sensor may be used by the
`controller 110 to issue processing interrupts or otherwise
`control operation of the printer 100.
`The other hardware 134 mayalso or instead include a
`heating element (instead of or in addition to the thermal
`element 130) to heat the working volume such as a radiant
`heater or forced hot air heater to maintain the object 112 at
`a fixed, elevated temperature throughouta build, or the other
`hardware 134 may include a cooling element to cool the
`working volume.
`FIG. 2 showsa three-dimensionalprinter. Theprinter 200
`may include a camera 202 and a processor 204. Theprinter
`200 may be configured for augmented operation using
`two-dimensional data acquired from the camera 202.
`The printer 200 may, for example, be any of the three-
`dimensional printers described above.
`The camera 202 may be any digital still camera, video
`camera, or other image sensor(s) positioned to capture
`images of the printer 200, or the working volume of the
`printer 200.
`The processor 204, which maybe an internal processor of
`the printer 200, an additional processor provided for aug-
`mented operation as contemplated herein, a processor of a
`desktop computeror the like locally coupled to the printer
`200, a server or other processor coupled to the printer 200
`through a data network,or any other processor or processing
`circuitry. In general, the processor 204 maybe configured to
`control operation of the printer 200 to fabricate an object
`from a build material. The processor 204 may be further
`configured to adjust a parameter of the printer 200 based
`upon an analysis of the object in the image. It should be
`appreciated that the processor 204 mayinclude a numberof
`different processors cooperating to perform the steps
`described herein, such as where an internal processorof the
`printer 200 controls operation of the printer 200 while a
`
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`

`US 10,556,381 B2
`
`5
`connected processor of a desktop computer performs image
`processing used to control print parameters.
`A variety of parameters maybe usefully adjusted during
`a fabrication process. For example, the parameter may be a
`temperature of the working volume. This temperature may
`be increased or decreased based upon, e.g., an analysis of
`road dimensions(e.g. height and width of line of deposited
`build material), or the temperature may be adjusted accord-
`ing to a dimensionalstability of a partially fabricated object.
`Thus, where sagging or other variations from an intended
`shape are detected,
`the temperature may be decreased.
`Similarly, where cooling-induced warping or separation of
`layers is detected, the temperature may be increased. The
`working volume temperature may be controlled using a
`variety of techniques such as with active heating elements
`and/or use of heated or cooled air circulating through the
`working volume.
`that may be usefully controlled
`Another parameter
`according to the camera image is the temperature ofa build
`platform in the working volume. For example, the camera
`202 maycapture an imageofa raft or other base layer for
`a fabrication, ora first layer of the fabricated object, and may
`identify defects such as improper spacing between adjacent
`lines of build material or separationof the initial layer from
`the build platform. The temperature of the build platform
`mayin such cases be heated in order to alleviate cooling-
`induced warping of the fabricated object at the object-
`platform interface.
`that may be usefully controlled
`Another parameter
`according to an analysis of the camera imageis the extrusion
`temperature of an extruder. By heating or cooling the
`extruder, the viscosity of a build material maybe adjusted in
`order to achievea desired material deposition rate and shape,
`as well as appropriate adhesionto underlyinglayers ofbuild
`material. Where roads of material deviate from a predeter-
`mined cross-sectional shape, or otherwise contain visible
`defects, the extrusion temperature of the extruder may be
`adjusted to compensate for such defects.
`Similarly, the parameter may be an extrusion rate of a
`build material from the extruder. By controlling a drive
`motor or other hardware that forces build material through
`the extruder, the volumetric rate of material delivery may be
`controlled, such as to reduce gaps between adjacentlines of
`build material, or to reduce bulges due to excess build
`material.
`
`
`
`In another aspect, the parameter may be a viscosity of
`build material, which maybe controlled, e.g., by controlling
`the extruder temperature or any other controllable element
`that can transfer heat to and from build material as it passes
`through the extruder. It will be understood that temperature
`control is one technique for controlling viscosity, but other
`techniques are known and maybe suitable employed, such
`as byselectively delivering a solventorthelike into the path
`of the build material in order to contro] thermal character-
`istics of the build material.
`Another parameter that may be usefully controlled is a
`movement speed of the extruder during an extrusion. By
`changing the rate of travel of the extruder, other properties
`of the build (e.g., road thickness, spatial rate of material
`delivery, and so forth) may be controlled in response to
`images captured by the camera 202 and analyzed by the
`processor 204.
`In anotheraspect, the parameter may bea layer height. By
`controlling the z-positioning hardware ofthe printer 200, the
`layer height may be dynamically adjusted during a build.
`The printer may include a memory 208, such as a local
`memory or a remote storage device, that stores a log of data
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`for an object being fabricated including without limitation a
`value or one or more of the parameters described above, or
`anyotherdata relating to a print. The memory 208 mayalso
`or instead store a log of data aggregated from a numberof
`fabrications of a particular object, which may include data
`from the printer 200 and/or data from a number of other
`three-dimensionalprinters.
`A second processor 210, such as a processor on a server
`or other remote processing resource, may be configured to
`analyze the log of data in the memory 208 to identify a
`feature of the object that is difficult to print. For example,
`where a comer, overhang, or the like consistently fails, this
`may be identified byanalysis of the log of data, particularly
`where such failures can be automatically detected based
`upon analysis of images from the camera 202. Suchfailures
`may be logged in any suitable manner including quantita-
`tively as data characterizing the failure (based upon image
`analysis), metadata (e.g., percent completion, build param-
`eters, and so forth) and/or a simple failure flag, which may
`be accompanied by an image of the failed build. In this
`manner, the second processor 210 can identify features that
`should be avoided in printable models, and/or objects that
`are generally difficult or impossible to print. The second
`processor 210 mayalso or instead be configured to analyze
`the results of variations in one or more of the parameters
`described above.It will be understood that, while the second
`processor 210 maybe usefullylocated on a remote process-
`ing resource such asa server, the second processor 210 may
`also be the same as the processor 204, with logging and
`related analysis performed locally bythe printer 200 or a
`locally coupled computer.
`The printer 200 may optionally include a display 212
`configured to display a view of the working volume. The
`display 212, which may obtain images of the working
`volume from the camera 202 or any other suitable imaging
`hardware, maybe configured, e.g., by the processor 204, to
`superimpose thermal data onto the view of the working
`volume. This may, for example, include thermistor data or
`data from other temperature sensors or similar instrumen-
`tation on the printer 200. For example, the printer 200 may
`includesensors for measuring a temperature of at least one
`of the extruder, the object, the build material, the working
`volume, an ambient temperature outside the working vol-
`ume, and a build platform within the working volume. These
`and any similar instrumentation may be used to obtain
`thermal data correlated to specific or general regions within
`and without the printer 200. Where the camera 202 includes
`an infrared camera, the thermal data may also or instead
`include an infrared image, or a thermal image derived from
`such an infrared image.
`The display 212 may serve other useful purposes. For
`example, the viewfrom the camera 202 may be presented in
`the display. The processor 204 may be configured to render
`an imageofa three-dimensional model used to fabricate an
`object from the pose of the camera 202. If the camera 202
`is a fixed camera then the pose maybe a predetermined pose
`corresponding to the camera position and orientation. If the
`camera 202 is a moving camera, the processor 204 may be
`further programmed to determine a pose of the camera 202
`based upon, e.g., fiducials or known, visually identifiable
`objects within the working volume such as comersof a build
`platform or a tool head, or to determine the pose using data
`from sensors coupled to the camera and/or from any actua-
`tors used to move the camera. The rendered imageof the
`three-dimensional model rendered from this pose may be
`superimposed on the viewof the working volume within the
`display 212. In this manner, the printer 200 may provide a
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`previewof an object based uponadigital three-dimensional of different surfaces of the object within the working vol-
`model, which preview may be rendered within the display
`ume.In another aspect, the one or more spatial sensors may
`212 for the printer, or a user interface ofthe display, with the
`include a single camera configured to navigate around the
`as-fabricated size, orientation, and so forth. In order to
`working volume, e.g., on a track or with an articulating arm.
`enhance the preview, other features such as build material
`Navigating around the working volume may more generally
`color may also be rendered using texture mappingorthe like
`include circumnavigating the working volume, moving
`for the rendered image. This may assist a user in selecting
`around and/or within the working volume, and/or changing
`build material, scaling, and so forth for an object that is to
`direction to achieve various poses from a single position.
`be fabricated from a digital model.
`The one or more spatial sensors mayalso orinstead include
`In another aspect, the printer 200 mayoptionally include
`articulating mirrors that can be controlled to obtain multiple
`a sensor 214 for capturing three-dimensional data from the
`views of an object from a single camera.
`object. A variety of suitable sensors are known in theart,
`In anotheraspect, the one or more spatial sensors 214 may
`suchas a laser sensor, an acoustical range finding sensor, an
`includecontrollable lighting that can be used, e.g., to obtain
`X-ray sensor, and a millimeter wave radar system, any of
`different shadowed viewsof an object that can be interpreted
`which maybe adapted alone or in various combinations to
`to obtain three-dimensional surface data. The processor 204
`capture three-dimensional data. The display 212 may be
`(or the second processor 210) may also provide a computer
`configured to superimpose such three-dimensionaldata onto
`automated design environment to view and/or modify the
`the display of the object within the working volume. In this
`digital model so that changes, adjustments, additions, and so
`manner, the processor 204 may detect one or more dimen-
`forth may be made prior to fabrication.
`sional inaccuracies in the object, such as by comparison of
`In another aspect, a tool head 220 of the printer may be
`three-dimensional measurements to a digital model used to
`usefully supplemented with a camera 222. The tool head 220
`fabricate the object. These may be presented as dimensional
`may include anytool, such as an extruder or the like, to
`annotations within the display 212,or as color-codedregions
`fabricate an object in the working volumeoftheprinter. In
`(e.g., yellow for small deviations, red for large deviations, or
`general, the tool head 220 may be spatially controlled by an
`any other suitable color scheme) superimposed on the dis-
`X-Y-Z positioning assembly of the printer, and the camera
`play of the object. The processor 206 may be further
`222 maybeaffixed to and moving with the tool head 220.
`configured to show summarydata in the display 212 con-
`The camera 222 may be directed toward the working vol-
`cerning any dimensional inaccuracies detected within the
`ume, such as downward toward a build platform, and may
`object.
`provide a useful bird’s eye view of an object on the build
`The sensor 214 may more generally include one or more
`platform. Theprocessor 204 may be configured to receive an
`spatial sensors configured to capture data from the object
`image from the camera and to provide diagnostic informa-
`placed within the working volume. The second processor
`tion for operation of the three-dimensional printer based
`210 (which maybe the processor 204) may convert this data
`upon an analysis of the image.
`into a digital modelofthe object, and the processor 204 may
`For example, the diagnostic information mayinclude a
`be configured to operate the printer 200 to fabricate a
`determination of a position of the tool head within the
`geometrically related object within the working volume
`working volume. The diagnostic information mayalso or
`instead include a determination of whether the three-dimen-
`based uponthedigital model. In this manner, the printer 200
`may be used for direct replication of objects simply by
`sional printer has effected a color change in build material.
`placing an object into the working volume, performing a
`The diagnostic information may also or instead include a
`scan to obtain the digital model, removing the object from
`determination of whether the three-dimensional printer has
`
`the working volume, and then fabricating a replica of the effected a change fromafirst build material to a second build
`object based upon the digital model. More generally, any
`material. The diagnostic information may also or instead
`include an evaluation of whether a build material is extrud-
`geometricallyrelated shape maybe usefully fabricated using
`ing correctly from the tool head. The diagnostic information
`similar techniques.
`For example, the geometrically related object may be a
`mayalso or instead include an evaluation ofwhetheran infill
`
`three-dimensional copy of the object, which may beascaled for the object is being fabricated correctly. In one aspect, the
`copy, and/or which may be repeated as many times as
`diagnostic information may include the image from the
`desired in a single build subject to spatial limitations of the
`camera, which maybe independently useful as a diagnostic
`tool.
`working volume and printer 200. In another aspect,
`the
`geometricallyrelated object may include material to enclose
`a portion of the object. In this manner, a container or other
`enclosure for the object may be fabricated. In anotheraspect,
`the geometrically related object may include a mating sur-
`face to the object, e.g., so that the fabricated object can be
`coupled to the original source object. This may beparticu-
`larly useful for fabrication of snap on parts such as aesthetic
`or functional accessories, or any other objects that might be
`usefully physically mated to other