Apparatus and method for fused deposition modeling 3D printing

Abstract

A 3D printer comprising: (a) a feed mechanism comprising a push motor adapted to push a solid filament through a feed conduit; and (b) a print head comprising a pull motor adapted to pull the filament from the conduit and direct the filament to a heated block in fluid communication with a print nozzle.

Description

[0001] Cross-references to related applications

[0002] This PCT application claims priority to Israel Application 279175, filed on December 3, 2021, under 35 U.SC §119(a), and the Israel Application is incorporated herein by reference in its entirety. Technical Field

[0003] This invention belongs to the field of 3D printing. Background Technology

[0004] There are three main types of 3D printing (also known as additive manufacturing): stereolithography (SLA); selective laser sintering (SLS); and fused deposition modeling (FDM). Although FDM was the most recently invented, it has become the dominant method of 3D printing, accounting for 46% of the 3D printing market as of 2018. FDM is also known as fused filament fabrication (FFF).

[0005] FDM uses a continuous filament (typically a thermoplastic polymer, but sometimes a metal) fed from a spool to an extruder that serves as the printhead. The extruder includes a heating element to soften the filament for extrusion through a nozzle. Droplets of the softened filament are deposited sequentially at desired locations under the control of a computerized controller that operates mechanical elements that move the printhead relative to a work surface (or the work surface relative to the printhead). After one layer is completed, the controller moves the printhead upward (or moves the work surface downward) in small increments and provides instructions for depositing the next layer on top of the previous one, thus producing the term additive manufacturing.

[0006] The initial input for computerized controllers is typically an STL (Stereolithography File Format) file generated by a CAD program. STL stores data based on the triangulation of the surfaces of the CAD model. Additive Manufacturing File Format (AMF) is a newer CAD file format more suitable for 3D printing, which uses curved triangulation to store information.

[0007] Typically, STL files are processed by "slicer" software to convert the model into a series of thin layers. The slicer software outputs a G-code file containing instructions tailored to the FDM printer. The G-code is used as input for the 3D printing client software (used by the controller during the printing process to instruct the print head).

[0008] The printer resolution describes the layer thickness and XY resolution in dots per inch (dpi) or micrometers (μm). Typical layer thicknesses range from 100 μm (250 DPI) to 16 μm (1,600 DPI). The XY resolution is as good as that of laser printers. Particle (3D dot) diameters range from approximately 50 μm to 100 μm (510 DPI to 250 DPI). For this printer resolution, specifying a mesh resolution of 0.01 mm to 0.03 mm and a chord length of ≤0.016 mm will generate the optimal STL output file for a given model input file. Summary of the Invention

[0009] A broad aspect of this invention relates to improvements in the speed and resolution of 3D printing. In some embodiments, multicolor printing is achieved in the same amount of time or less compared to monochrome printing using previously available equipment.

[0010] One aspect of some embodiments of the present invention relates to the coordinated operation of a “push” motor located away from the printhead and a “pull” motor located adjacent to the printhead. In some embodiments, multiple “push” motors are used for different filament colors. According to various exemplary embodiments of the invention, two, three, four, five, six, or more push motors are used for a corresponding number of colors and / or different materials. According to these embodiments, a splitter is deployed between the multiple “push” motors and the “pull” motors. Alternatively or additionally, in some embodiments, the “pull motor” is equipped with a variable tension mechanism that allows adjustment of the tension based on the filament being pulled at any given time. In some embodiments, the variable tension mechanism is controlled by a computerized controller. In some embodiments, this controller is integrated with a controller that performs other functions. In some exemplary embodiments of the invention, the controller responds to an output signal from a sensor in the pull motor that indicates the current of the pull motor. According to various exemplary embodiments of the present invention, the distance between the push motor and the pull motor is less than 50 cm, less than 45 cm, less than 40 cm, less than 35 cm, less than 30 cm, less than 25 cm, less than 20 cm, less than 15 cm, or an intermediate distance or smaller. Alternatively or additionally, in some embodiments, the distance between the push motor and the pull motor is greater than 15 cm, greater than 20 cm, greater than 25 cm, greater than 30 cm, greater than 35 cm, greater than 40 cm, greater than 45 cm, greater than 50 cm, or an intermediate distance or larger. In some exemplary embodiments of the present invention, the distance between the push motor and the pull motor is in the range of 30 cm to 42 cm, 33 cm to 39 cm, or 35 cm to 37 cm. In some exemplary embodiments of the present invention, two, three, four, or more push-fit connectors arranged in series retain the conduit through which the wire is pushed to the feed port. In some embodiments, increasing the number of connectors helps to increase the possible distance between the "push" motor and the "pull" motor.

[0011] Another aspect of some embodiments of the present invention relates to the coordinated movement of a filament feed assembly and a printhead located at a distance from the filament feed assembly. In some embodiments, multiple filament feed assemblies are employed for different filament colors and / or different materials. According to various exemplary embodiments of the invention, two, three, four, five, six, or more filament feed assemblies are employed for a corresponding number of colors. Alternatively or additionally, in some embodiments, the filament feed assembly is vertically offset relative to the printhead. Alternatively or additionally, in some embodiments, a single controller coordinates the operation of the filament feed assembly drive mechanism and the printhead drive mechanism. In some embodiments, the filament feed assembly drive mechanism moves the filament feed assembly back and forth along a single axis (e.g., the Y-axis). Alternatively or additionally, in some embodiments, the printhead drive assembly moves the printhead along two axes (e.g., X and Y). In some embodiments, the controller coordinates the operation of the filament feed assembly drive mechanism and the printhead drive mechanism such that the distance between the filament feed assembly and the printhead is as described in the context of the first aspect.

[0012] Another aspect of some embodiments of the present invention relates to reducing the total distance traveled by the print head when printing a single layer or a set of layers of an object. In some embodiments, a reduction in travel distance contributes to a reduction in printing time. For an object having two or more colors in a layer, calculations can be performed separately for each color. In some embodiments, a reduction in the number of color change events contributes to a reduction in printing time for the object.

[0013] Another aspect of some embodiments of the present invention relates to incorporating an induction heating element in the printhead. In some embodiments, the use of induction heating facilitates faster temperature changes, which in turn facilitates faster viscosity changes in the thermoplastic material used as the printing medium. In some embodiments, these faster viscosity changes contribute to improved printing accuracy.

[0014] Another aspect of some embodiments of the present invention relates to the parallel printing of multiple identical objects. According to various exemplary embodiments of the invention, two, three, four, five, six, seven, eight, or more identical objects can be printed in parallel within the time required to print a single object. In some embodiments, a single controller operates multiple push and pull motors (as described in the first aspect) and / or multiple filament feed assembly drives and printhead drives (as described in the second aspect) and / or multiple induction heating elements in multiple printheads (as described in the fourth aspect) and / or multiple color mixing printheads (as described in the fifth aspect). Alternatively or additionally, in some embodiments, the controller drives the printheads in parallel using a reduced total travel distance per layer and / or a reduced number of color changes as described in the third aspect.

[0015] It will be recognized that the above aspects relate to solutions to technical problems related to reducing printing time for a given object relative to previously available alternatives.

[0016] Alternatively or additionally, it will be understood that the above aspects relate to solutions to technical problems related to the production of 3D printed objects with three or more colors.

[0017] In some exemplary embodiments of the present invention, a 3D printer is provided, comprising: (a) a feed mechanism including a push motor adapted to push a solid filament through a feed guide; and (b) a print head including a pull motor adapted to pull the filament from the guide and guide the filament to a heating block in fluid communication with a print nozzle. In some embodiments, the printer includes a controller configured to coordinately operate the push motor, the pull motor, and the print nozzle. Alternatively or additionally, in some embodiments, the printer includes two or more feed mechanisms connected to the print head via the same number of guides. Alternatively or additionally, in some embodiments, the printer includes: a first support rod on which the feed mechanisms are mounted; and a second support rod on which the print head is mounted. Alternatively or additionally, in some embodiments, the feed mechanism includes two or more push-fit connectors mounted in series to lock the end of the feed guide to an output port in the feed mechanism. Alternatively or additionally, in some embodiments, the feeding mechanism includes an adhesive that adheres the end of the feeding conduit to the output port in the feeding mechanism.

[0018] In some exemplary embodiments of the present invention, a 3D printer is provided, comprising: (a) a first support rod on which one or more feed mechanisms are mounted, the first support rod being operably connected to a first drive system configured to provide linear movement in two directions along one axis; (b) a second support rod on which a print head is mounted, the second support rod being operably connected to a second drive system configured to provide linear movement in two directions along one axis parallel to the first drive system; and (c) a third drive system configured to provide parallel linear movement of the print head relative to the second support rod in two directions.

[0019] In some embodiments, the printer includes a controller configured to coordinate the operation of the first, second, and third drivetrains. Alternatively or additionally, in some embodiments, the printer includes a fourth drivetrain configured to provide parallel linear movement of the one or more feed mechanisms relative to the first lever in two directions. Alternatively or additionally, in some embodiments, the printer includes a controller configured to coordinate the operation of the first, second, third, and fourth drivetrains. Alternatively or additionally, in some embodiments, the printer includes two or more feed mechanisms connected to the printhead via the same number of conduits. Alternatively or additionally, in some embodiments, the printer includes a controller configured to operate a single feed mechanism at a time according to a specified color in a program file for the object being printed. Alternatively or additionally, in some embodiments, the feed mechanism includes two or more GrooveMount Bowden adapters and / or Festo fittings mounted in series to lock the ends of the feed conduits to output ports in the feed mechanism.

[0020] In some exemplary embodiments of the present invention, a method is provided, the method comprising: (a) calculating, using a data processor, a shortest path for all points of a single color in one or more layers of a 3D object described by a G-code file; (b) transmitting the shortest path to a controller of a 3D printer; and (c) printing, using the 3D printer, all points of a single color in one or more layers of the 3D object described by the G-code file. In some embodiments, the calculation involves a single layer. Alternatively or additionally, in some embodiments, the calculation involves a set of two or more layers. Alternatively or additionally, in some embodiments, the method comprises (d) repeating (a), (b), and (c) for another single color until all colors in one or more layers have been printed. Alternatively or additionally, in some embodiments, the method comprises (e) repeating (a), (b), (c), and (d) for another one or more layers until all colors in all layers of the 3D object have been printed. Alternatively or additionally, in some embodiments, the method includes doubling the number of layers used for the last color, such that the last color becomes the first color repeated at (e).

[0021] In some exemplary embodiments of the present invention, a 3D printer is provided, comprising an FDM (Fused Deposition Modeling) printhead including an induction heater for melting material. In some embodiments, melting facilitates the ability of material to pass through the print nozzle.

[0022] In some exemplary embodiments of the present invention, a method is provided, comprising: (a) feeding filament to each of the n printheads from n feed mechanisms in corresponding groups spaced at least 10 cm apart from the n printheads; (b) controlling the position and printing state of the n printheads by a single controller that simultaneously provides parallel instructions to each of the n printheads; and (c) switching to different corresponding groups of n feed mechanisms using the single controller. In some embodiments, the method includes controlling the position of the n feed mechanisms in all corresponding groups by a single controller that simultaneously provides parallel instructions to each of the n feed mechanisms in all groups.

[0023] In some exemplary embodiments of the present invention, a 3D printer is provided, comprising: (b) at least X groups of n filament feed mechanisms operably connected to a first drive system configured to provide linear motion in two directions along one axis; (c) X printheads operably connected to a second drive system configured to provide linear motion in two directions along one axis parallel to the first drive system; and (d) a third drive system configured to provide linear motion of the X printheads in two directions along a vertical axis; wherein n ≥ 2. In some embodiments, the printer includes a controller configured to coordinate the operation of the first, second, and third drive systems. Alternatively or additionally, in some embodiments, the printer includes a fourth drive system configured to provide linear motion of the X groups of n feed mechanisms in two directions along a vertical axis. Alternatively or additionally, in some embodiments, the printer includes a controller configured to coordinate the operation of a first drivetrain, a second drivetrain, a third drivetrain, and a fourth drivetrain. Alternatively or additionally, in some embodiments, the controller is configured to operate a single filament feed mechanism in each of X groups at a time, according to a specified color in a program file for the object being printed. Alternatively or additionally, in some embodiments, the filament feed mechanism includes two or more push-fit connectors mounted in series to lock the end of the feed guide tube to an output port in the feed mechanism.

[0024] In some exemplary embodiments of the present invention, an FDM printing method is provided, comprising: depositing 1000 grams of thermoplastic filament over 24 hours from a single printhead having a nozzle having a diameter of 0.4 mm to 0.8 mm using a filament feed of 1.75 mm diameter. In some embodiments, the method includes printing in at least two colors. Alternatively or additionally, in some embodiments, the method includes printing in at least four colors. Alternatively or additionally, in some embodiments, the method includes operating at least two single printheads via a single controller. Alternatively or additionally, in some embodiments, the method includes operating at least four single printheads via a single controller. Alternatively or additionally, in some embodiments, the method includes operating at least eight single printheads via a single controller.

[0025] In some exemplary embodiments of the present invention, a connector assembly is provided, the connector assembly comprising: (a) a cover having an inner cavity; (b) a conduit passing through the cavity; and (c) at least two push-fit connectors that engage a portion of the conduit in series and contact the inner wall of the cavity.

[0026] In some exemplary embodiments of the present invention, a connector assembly is provided, the connector assembly comprising: (a) a cover having an inner cavity; (b) a conduit passing through the cavity; and (c) an adhesive that attaches a portion of the conduit to the inner wall of the cavity.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although suitable methods and materials are described below, similar or equivalent methods and materials may be used in the practice of this invention. In case of conflict, the patent specification, including its definitions, shall prevail. All materials, methods, and examples are illustrative only and are not intended to be limiting.

[0028] As used herein, the terms “comprising” and “including” or their grammatical variations shall be regarded as specifying the inclusion of the stated feature, integer, action, or component, without excluding the addition of one or more additional features, integers, actions, components, or groups thereof. This term is broader than the terms “consisting of” and “substantially consisting of” as defined in the Manual of Patent Examination Procedure of the United States Patent and Trademark Office, and includes the terms “consisting of” and “substantially consisting of”. Therefore, any statement that an embodiment “comprising” or “including” a feature is a specific statement that a sub-implementation “substantially consists of” and / or “consisting of” the stated feature.

[0029] The phrase “consistently of…” or its grammatical variations as used herein shall be regarded as specifying the described feature, integer, step or component, but do not preclude the addition of one or more additional features, integers, steps, components or groups thereof, provided that the additional features, integers, steps, components or groups thereof do not materially alter the essential and novel features of the claimed composition, apparatus or method.

[0030] The phrase “suitable” as used in this specification and the appended claims applies additional structural limitations to the foregoing components.

[0031] The term "method" refers to the manner, means, techniques and procedures used to accomplish a given task, including but not limited to manner, means, techniques and procedures known to practitioners of architecture and / or computer science or readily developed from known manner, means, techniques and procedures.

[0032] The implementation of the methods and systems according to embodiments of the present invention involves manually, automatically, or a combination of manual and automatic execution of selected tasks or steps. Furthermore, in practical instruments and devices according to exemplary embodiments of the methods, apparatus, and systems of the present invention, several selected steps can be implemented by hardware or by software on any operating system with any firmware, or a combination thereof. For example, as hardware, the selected steps of the present invention can be implemented as chips or circuits. As software, the selected steps of the present invention can be implemented as a plurality of software instructions executed by a computer using any suitable operating system. In any case, the selected steps of the methods and systems of the present invention can be described as being executed by a data processor, such as a computing platform for executing multiple instructions. Attached Figure Description

[0033] To understand the invention and how to practice it, various embodiments will now be described by way of non-limiting example only with reference to the accompanying drawings. In the drawings, the same or similar structures, elements, or portions thereof appearing in more than one drawing are generally labeled with the same or similar reference numerals in the drawings in which they appear. The dimensions of the parts and features shown in the drawings are chosen primarily for ease of representation and clarity and are not necessarily drawn to scale. The drawings are as follows:

[0034] Figure 1 This is a schematic top perspective view of a system according to some exemplary embodiments of the present invention;

[0035] Figure 2A This is a transverse cross-section of a 3D printer printhead according to some exemplary embodiments of the present invention;

[0036] Figure 2B It is a transverse cross-section of a portion of the printhead of a 3D printer according to an additional exemplary embodiment of the present invention;

[0037] Figure 2C This is a transverse cross-section of a filament splitter for use in conjunction with a 3D printer printhead, according to some exemplary embodiments of the present invention.

[0038] Figure 2D yes Figure 2C A top-view perspective view of a wire splitter;

[0039] Figure 2E This is a side-view stereoscopic semi-transparent view of a variable tensioning mechanism suitable for use with a pull motor, according to some exemplary embodiments of the present invention;

[0040] Figure 3A This is a transverse cross-section of a conduit connector having two push-fit connectors according to some exemplary embodiments of the present invention;

[0041] Figure 3B This is a transverse cross-section of a conduit connector having four push-fit connectors according to some exemplary embodiments of the present invention;

[0042] Figure 3C This is a transverse cross-section of a conduit connector with adhesive according to some exemplary embodiments of the present invention;

[0043] Figure 4A This is a perspective view applicable to belt drive systems used in various exemplary embodiments of the present invention;

[0044] Figure 4B is Figure 4A Front view of the drivetrain;

[0045] Figure 4CThis is a perspective view applicable to ball screw drives used in various exemplary embodiments of the present invention;

[0046] Figure 4D yes Figure 4C Front view of the drivetrain;

[0047] Figure 5A This is a simplified flowchart of a method according to some exemplary embodiments of the present invention;

[0048] Figure 5B This is a schematic diagram of a print head for printing multi-color objects according to some exemplary embodiments of the present invention;

[0049] Figure 6 This is a simplified flowchart of a method according to some exemplary embodiments of the present invention;

[0050] Figure 7 This is a schematic top perspective view of a system according to some exemplary embodiments of the present invention;

[0051] Figure 8 This is a simplified flowchart of a method according to some exemplary embodiments of the present invention; and

[0052] Figure 9 This is a schematic front view of a system according to some exemplary embodiments of the present invention. Detailed Implementation

[0053] Embodiments of the present invention relate to 3D printers and related methods, as well as to extruders used in 3D printing and methods for producing filaments.

[0054] Specifically, some embodiments of the present invention can be used to improve the speed and / or resolution of 3D printing and / or increase the number of colors in a 3D printed object to three or more colors and / or to three or more filament types.

[0055] The principles and operation of the apparatus and / or methods according to exemplary embodiments of the present invention can be better understood with reference to the accompanying drawings and description.

[0056] Before detailing at least one embodiment of the invention, it will be understood that the invention is not limited in its application to the details set forth in the following description or illustrated by example. The invention can have other embodiments or can be implemented or performed in various ways. Furthermore, it will be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0057] Exemplary printer

[0058] Figure 1This is a schematic top perspective view of a 3D printing system, generally represented as 100, according to some exemplary embodiments of the present invention.

[0059] Figure 2A It is a transverse cross-section of a portion of a fused deposition modeling 3D printer printhead, generally represented as 121 according to some exemplary embodiments of the present invention.

[0060] The illustrated exemplary 3D printer 100 includes a support frame 130 to which other components are attached directly or indirectly.

[0061] The illustrated exemplary 3D printer 100 further includes: one or more feed mechanisms 112, each including a push motor adapted to push a solid filament through a feed guide 114 (a dashed rectangle surrounding the guide assembly); and a print head 122 including a pull motor adapted to pull the filament from the guide 114 and guide it to a heating block 210 in fluid communication with a print nozzle 214. Figure 2A Heating block 210 is heated by electric coil 212.

[0062] The feed mechanism 112 is a commercially available extruder with a modified connector 113, sold for use in 3D printing. An example of an extruder suitable for use in this case is the "BONDTECH Mini Gear (BMG) 3D Extruder" (Bondtech AB, Sweden). (Further details are provided below.) Figure 3A , Figure 3B and Figure 3C Connector 113 is described in the context of [the previous section]. Exemplary wire materials are described below.

[0063] In the depicted embodiments, controller 128 is configured to coordinately operate the push motor, pull motor, and print nozzle. In some exemplary embodiments of the invention, controller 128 also controls the tension applied to the filament by the pull motor.

[0064] In the depicted embodiments, the printer 100 includes two or more feed mechanisms 112 (four feed mechanisms are described), which are connected to the print head 122 via the same number of conduits 114. In some embodiments, each feed mechanism 112 provides filaments of a different color and / or filaments of a different material. According to various exemplary embodiments of the invention, two, three, four, five, six, or more filament feed mechanisms 112 are used for corresponding numbers of colors and / or materials.

[0065] The filament from the feed mechanism 112 converges at the filament splitter attached to the printhead 122, as described below.

[0066] In the depicted embodiments, the printer 100 includes: a first support rod 110 on which a feed mechanism 112 is mounted; and a second support rod 120 on which a printhead 122 is mounted. According to various exemplary embodiments of the invention, the distance between the drive motor of the feed mechanism 112 and the pull motor of the printhead 122 is 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, or an intermediate distance or less. In some embodiments, the first support rod 110 is vertically offset relative to the second support rod 120. In some embodiments, this distance contributes to a reduction in vibration from the drive motor of the feed mechanism 112 at the printhead 122. In some embodiments, this reduction in vibration contributes to improved printing accuracy. In some embodiments, the conduits 114 are made of flexible tubing, thus damping vibration.

[0067] Friction generated by the movement of the feed tube 114 may cause the connector 113 to disengage from the feed mechanism 112. In some embodiments, the connector 113 of the feed mechanism 112 includes two or more push-fit connectors (e.g., slot-mount Bowden adapters and / or Festo fittings) mounted in series to lock the end of the feed tube 114 to the output port in the feed mechanism 112. Alternatively or additionally, in some embodiments, the connector 113 of the feed mechanism 112 includes an adhesive that adheres the end of the feed tube 114 to the output port in the feed mechanism 112.

[0068] Figure 2E This is a side-view stereoscopic semi-transparent view of a variable tensioning mechanism, generally designated 2000, suitable for use with a pull motor of a feed mechanism 122, according to some exemplary embodiments of the present invention.

[0069] In some exemplary embodiments of the invention, a variable tension mechanism 2000 is used in the pull motor of the feed mechanism 122 to adjust the tension according to the wire being pulled at any given time. Tension adjustment is useful, for example, in cases where several different wire types can be used in the splitter 220 described below. In some exemplary embodiments of the invention, the variable tension mechanism 2000 is controlled by a controller 128 (… Figure 1Controlled by a single controller (not described). Controller 128 is an integrated controller that performs the other functions described above. In some exemplary embodiments of the invention, a current sensor (not described) on the pull motor provides an output signal to the controller (e.g., 128), and the controller adjusts the tensioning mechanism 2000 in response to the output signal received from the current sensor. The use of the output signal from the current sensor on the extruder motor is described in (Progress in Additive Manufacturing (2019) 4:211-223) by Telegenov et al., which is incorporated herein by reference in its entirety.

[0070] The depicted exemplary variable tensioning mechanism 2000 includes: a toothed drive gear 2010 powered by a drive shaft 2011 connected to a motor (not described); and a toothed tensioning gear 2012 that rotates freely about an axis 2013. In the depicted embodiment, the drive shaft 2011 passes through a support wall 2030, such that the drive gear 2010 is in a fixed position relative to the support wall 2030.

[0071] When the distance between drive shaft 2011 and shaft 2013 decreases, the tension on the wire pulled through the space between gears 2010 and 2012 increases. Conversely, when the distance between drive shaft 2011 and shaft 2013 increases, the tension on the wire pulled through the space between gears 2010 and 2012 decreases.

[0072] In the depicted embodiment, the distance between the drive shaft 2011 and the shaft 2013 can be adjusted by rotating the toothed distance control gear 2020, which is controlled by a controller (e.g., Figure 1 A motor (not described) controlled by 128 in the figure provides power. The rotational motion of the toothed distance control gear 2020 is converted into linear motion of the drive track 2022 by complementary teeth on the track 2022 that engage with the teeth of the gear 2020. The linear motion of the track 2022 causes the support frame 2026 of the shaft 2013 to move relative to the wall 2030. (The shaft 2013 is engaged by the frame 2026 but not by the wall 2030.) The movement of the support frame 2026 causes the shaft 2013 and the tension gear 2012 to move toward or away from the drive gear 2010 according to the direction of motion. In the depicted embodiment, a guide rod 2024, via a guide bracket 2040 (only one guide bracket 2040 is visible in the figure), helps maintain the correct orientation of the support frame 2026 relative to the support wall 2030.

[0073] There are commercially available variable tension mechanisms that can be incorporated into printers according to exemplary embodiments of the present invention. Examples of such variable tension mechanisms include, but are not limited to, those described above. Large gear extruder and Extruders (both manufactured by Bondtech AB, Sweden). These adjustable tensioning mechanisms are designed for manual adjustment, but the controller interface can be easily designed and implemented by those skilled in the art with the help of this instruction manual.

[0074] Exemplary wire splitter

[0075] Figure 2C It is a transverse cross-section of a filament splitter, generally represented as 125, for use in conjunction with a 3D printer printhead according to some exemplary embodiments of the present invention.

[0076] Figure 2D yes Figure 2C The overall representation of the mitotic apparatus is shown in the top-view perspective of 127.

[0077] exist Figure 2C and Figure 2D In the middle, the splitter 220 includes multiple wire inlet ports 230 (in Figure 2D Four ports 230 are depicted, but the actual number varies depending on the number of feed mechanisms 112 associated with a single printhead 122. In various exemplary embodiments of the invention, six, eight, ten, or twelve ports 230 are provided in the splitter 220. In use, the ports 230 are connected to individual feed conduits 114. In some embodiments, they are connected to connector assemblies comprising one or more push-fit connectors, such as slot-mount Bowden adapters and / or Festo fittings. In some embodiments, push-fit connectors are used in series, such as… Figure 3A ; Figure 3B and Figure 3C As described in the context.

[0078] Port 230 is in fluid communication with filament guide 240, which converges at printhead connector 240. Figure 2C Connector 242 is configured to attach to printhead 122. Exemplary attachment configurations for connector 242 and printhead 122 include threaded, twist-lock, and snap-fit ​​engagements.

[0079] When the splitter 220 is mounted on the printhead 122, the type of filament fed through the printhead at any given time is controlled by which feed mechanism 112 is operated by the controller 128 at that time.

[0080] An example of a commercially available splicing unit suitable for use in the various exemplary embodiments of the present invention is the M2P1 Hotend 24V splicer (manufactured by XIAOMINDIAN-HAT). Other splicing units are also commercially available and can be easily replaced.

[0081] Additional Exemplary Printer

[0082] Also refer to Figure 1 In some embodiments, the printer 100 includes a first support rod 110 on which one or more feed mechanisms 112 are mounted. In the depicted embodiment, the first support rod is operably connected to a first drivetrain 111 (symbolically indicated as a double-headed arrow), the first drivetrain 111 being configured to provide linear movement in two directions along one axis.

[0083] In the depicted embodiment, the printer 100 includes a second support rod 120 on which a printhead 122 is mounted. In some embodiments, the second support rod 120 is operatively connected to a second drive system 123 (symbolically indicated as a double-headed arrow) and a third drive system 125 (symbolically indicated as a double-headed arrow), the second drive system 123 being configured to provide linear movement in two directions along one axis parallel to an axis of a first drive system 111, and the third drive system 125 being configured to provide parallel linear movement of the printhead 122 relative to the second rod 120 in two directions.

[0084] In the depicted embodiments, controller 128 is configured to coordinate the operation of the first drivetrain 111, the second drivetrain 123, and the third drivetrain 125. In some embodiments, the coordinated operation ensures that the distance between the print head 122 and each of the feed mechanisms 112 does not exceed the length of the associated conduit 114. In addition to the primary function of controller 128, this coordinated operation guides the print head 122 to deposit droplets of filament for printing 3D objects specified by G-code files or other printing specification files.

[0085] In some embodiments, the printer 100 includes a fourth drivetrain 115 (symbolically indicated by a double-headed arrow), configured to provide one or more feed mechanisms 112 with respect to the first lever 110 in two parallel linear directions. According to these embodiments, a controller 128 is configured to coordinate the operation of the first drivetrain 111, the second drivetrain 123, the third drivetrain 125, and the fourth drivetrain 115. The coordinated operation is as described above.

[0086] In the depicted embodiments, printer 100 includes two or more feed mechanisms 112 (four feed mechanisms are described), which are connected to printhead 122 via the same number of conduits 114. In some embodiments, each feed mechanism provides filaments of a different color and / or a different material. According to various exemplary embodiments of the invention, two, three, four, five, six, or more feed mechanisms 112 are used for corresponding numbers of different colors and / or different materials. In some embodiments, controller 128 operates a single feed mechanism 112 at a time according to a specified color and / or material in a program file for the object to be printed. In some embodiments, the feed mechanisms 112 employ two or more push-fit connectors mounted in series (e.g., slot-mount Bowden adapters and / or Festo fittings) to lock the ends of the feed conduits 114 to the output ports in the feed mechanism. (See also...) Figure 3A and Figure 3B (and the accompanying description). In some embodiments, the feed mechanism 112 employs an adhesive to lock the end of the feed conduit 114 to the output port in the feed mechanism. (See also...) Figure 3C (and accompanying description).

[0087] Exemplary drivetrains suitable for use in cases 111, 123, 115, and 125 are described in the following sections.

[0088] Exemplary drive system

[0089] Figure 4A This is a perspective view of a belt drive system, generally represented as 400, suitable for use in various exemplary embodiments of the present invention. Figure 4B is... Figure 4A The overall representation of the drivetrain is shown in the front view at 402. In the depicted embodiment, motor 410 rotates drive shaft 412. Friction between shaft 412 and an annular belt 414 causes belt 414 to rotate about drive shaft 412 and driven shaft 416. Guide plate 422 is fixedly attached to belt 415 such that the plate moves along guide notch 420 in plate support rod 418 as the belt rotates. When the rotation direction of drive shaft 412 is reversed, the travel direction of plate 422 is reversed. According to various exemplary embodiments of the invention, guide plate 422 is attached to 110 and / or 120 and / or 122 and / or 112. In some embodiments, the passive guide mechanism having only guide plate 422 and support rod 418 operates in parallel (e.g., at opposite ends of 110 and / or 120). In other exemplary embodiments of the invention, the entire drive mechanism is replicated at opposite ends of 110 and / or 120. Alternatively or additionally, in some embodiments, the support portion in the guide recess 420 helps reduce friction between the guide plate 422 and the support rod 418. The support frame 130 is similar to... Figure 1 The supporting frame 130 in the middle.

[0090] Figure 4C This is a perspective view of a ball screw drive system, generally represented as 404, suitable for use in various exemplary embodiments of the present invention. Figure 4D yes Figure 4C The overall representation of the transmission system is shown in the front view of 406. In the depicted embodiment, a motor 430 rotates a ball screw 432 that passes through a structure mounted on the moving part. Figure 4C The ball nut 434 is located below the second support rod 120. Rotation of the ball screw 432 in one direction moves the ball nut 432 away from the motor 430, and rotation of the ball screw 432 in the opposite direction moves the ball nut 432 toward the motor 430. According to various exemplary embodiments of the invention, the ball nut 432 is attached to 110 and / or 120 and / or 122 and / or 112. In some embodiments, the passive guiding mechanism operates in parallel (e.g., at opposite ends of 110 and / or 120). In other exemplary embodiments of the invention, the entire transmission mechanism is replicated at opposite ends of 110 and / or 120. The support frame 130 is similar to... Figure 1 The supporting frame 130 in the middle.

[0091] Exemplary methods

[0092] Figure 5A This is a simplified flowchart of a method, generally represented as 500, that helps to improve the speed of 3D printing operations according to some exemplary embodiments of the present invention.

[0093] The depicted exemplary method 500 includes using a data processor 510 to calculate the shortest travel path for all points of a single color in one or more layers of a 3D object described by a G-code file. In the depicted implementation, method 500 includes transmitting the shortest travel path output by the data processor to the controller of the 3D printer (e.g., ...). Figure 1 In step 128), the 3D printer is used to print 530 all points of a single color in one or more layers of the 3D object described in the G-code file. In some embodiments, calculation 510 involves a single layer. In some embodiments, calculation 510 involves a set of two or more layers.

[0094] In the depicted implementation, method 500 includes repeating 510, 520, and 530 for each additional individual color until all colors in one or more layers have been printed.

[0095] In the depicted implementation, method 500 includes repeating 510, 520, 530, and 540 for one or more additional layers until all colors in all layers of the 3D object have been printed. In some implementations, method 500 includes doubling the number of layers used for the last color, such that the last color becomes the first color repeated at 550.

[0096] For a printing operation with N colors, where each color is printed once in X layers:

[0097] In the first round, each of the colors 1 to (N-1) is printed once in layer X;

[0098] Color N is printed in layers 2X, where the last X layers in those layers are used as the first step in the second round (510).

[0099] In the second round, each color from 1 to (N-2) is printed once in layer X;

[0100] Color (N-2) is printed in the 2X layer, where the last X layer of those layers is used as the first step 510 in the third round.

[0101] Figure 5B This is a schematic diagram of a printhead 512 for printing multi-color objects according to some exemplary embodiments of the present invention. In the depicted embodiments, nozzle 512 prints two or more layers with material 524 and / or 526, and then returns to print with 522. The determination of how many layers to print sequentially with a particular material takes into account the nozzle geometry of printhead 512 and the nozzle's descent capability without damaging previously printed portions of the object. In some exemplary embodiments of the invention, nozzle 512 prints up to three layers at a time for a particular filament type / color. In some embodiments, mechanical modifications to the nozzle geometry facilitate the ability to print more than three layers at a time for a particular filament type / color.

[0102] Exemplary induction heating implementation

[0103] Figure 2B It is a lateral cross-section of a portion of the overall representation of the 3D printer printhead according to an additional exemplary embodiment of the present invention, denoted as 123.

[0104] In the depicted embodiments, 123 is part of an FDM (Fused Deposition Modeling) printhead including an induction heater 252 for melting material in a loading tube 213 so that the material can pass through a print nozzle 214. In some embodiments, the induction heater 252 heats block 210 and / or tube 213. In some exemplary embodiments of the invention, the induction heater 252 directly heats the material in tube 213. In some embodiments, metal ions in the material of the filament in tube 213 contribute to improving the efficiency of direct induction heating. In some exemplary embodiments of the invention, colored thermoplastic polymer filaments containing metal ions in their dyes are induction heated. In other exemplary embodiments of the invention, metal filaments are used for printing.

[0105] Additional Exemplary Methods

[0106] Figure 6 This is a simplified flowchart of a method for printing the same object in parallel, with a total representation of 700, according to some exemplary embodiments of the present invention.

[0107] The exemplary method 700 described includes supplying 710 filaments to each of the n printheads from n feed mechanisms in a corresponding group spaced at least 10 cm apart from the n printheads, and controlling 720 the position and printing state of the n printheads by a single controller that simultaneously provides parallel instructions to each of the n printheads.

[0108] In some implementations, the controller operates one or more drives to which n printheads are attached. Thus, each printhead prints the same item in parallel. According to various exemplary embodiments of the invention, each group of n feed mechanisms includes 2, 3, 4, 5, 6, 7, or 8 or more feed mechanisms, wherein each feed mechanism in the group is loaded with a different filament type and / or filament color.

[0109] In the depicted implementation, method 700 includes using a single controller to switch 730 to n feed mechanisms in different corresponding groups. In some implementations, each group of feed mechanisms is loaded with different filaments (e.g., different colors and / or different materials).

[0110] In the depicted implementation, method 700 includes controlling the positions of n feed mechanisms in a corresponding group 740 by a single controller that simultaneously provides parallel instructions to each of the n feed mechanisms. In some implementations, this keeps the distance between the printhead and the feed mechanism within a desired range (i.e., less than the length of the conduit connecting the feed mechanism to the printhead).

[0111] In the depicted implementation, method 700 includes controlling the position of n feed mechanisms in all corresponding groups 750 by a single controller that simultaneously provides parallel instructions to each of the n feed mechanisms in all groups (i.e., keeping the position of the feed mechanism sufficiently close to the printhead, so that the distance is less than the length of the conduit connecting the feed mechanism to the printhead).

[0112] Exemplary parallel printing system

[0113] Figure 7 This is a schematic top perspective view of a parallel printing system, generally represented as 800, according to some exemplary embodiments of the present invention.

[0114] The depicted exemplary parallel 3D printing system 800 includes: at least X groups 812 (dashed ellipses) of n filament feed mechanisms 810 operatively connected to a first drivetrain 820 (symbolically indicated by a series of double-headed arrows; surrounded by dashed ellipses), the first drivetrain 820 configured to provide linear motion in two directions along one axis; X printheads 830 operatively connected to a second drivetrain 840 (symbolically indicated by double-headed arrows), the second drivetrain 840 configured to provide linear motion in two directions along one axis parallel to one axis of the first drivetrain 820; and a third drivetrain 850 (symbolically indicated by double-headed arrows), the third drivetrain 850 configured to provide linear motion of the X printheads 830 in two directions along a vertical axis. In the depicted embodiment, X = 3 and n = 4. In the depicted embodiment, the feed mechanism 810 is connected to the print head 830 via a conduit 814. According to various exemplary embodiments of the invention, n>2; n>3; n>4; n>5; n>6; n>7 or n>8 or a larger integer.

[0115] In the depicted embodiments, system 800 includes a controller 828 configured to coordinately operate a first drivetrain 820, a second drivetrain 840, and a third drivetrain 850. Coordinated operation is as described above. In some embodiments, system 800 includes a fourth drivetrain 860 (symbolically indicated by a double-headed arrow), configured to provide linear movement of the n feed mechanisms of the X groups in two directions along the vertical axis. According to these embodiments, controller 828 is configured to coordinately operate the first drivetrain 820, the second drivetrain 840, the third drivetrain 850, and the fourth drivetrain 860.

[0116] In some embodiments, each feed mechanism 810 within a set of 812 provides a different color and / or a different type of material. According to various exemplary embodiments of the invention, n = 1, 2, 3, 4, 5, 6 or more, to represent a corresponding number of colors and / or material types.

[0117] Alternatively or additionally, in some implementations, controller 838 is configured to operate a single filament feed mechanism in each of the X groups at a time, according to the specified color and / or material in the program file of the object being printed.

[0118] Alternatively or additionally, in some embodiments, each wire feed mechanism 810 employs two or more push-fit connectors in series to lock the end of the feed guide tube 814 to the output port in the feed mechanism 810. In some embodiments, the push-fit connectors are slot-mount Bowden adapters and / or Festo fittings. See details. Figure 3A and Figure 3B And its accompanying description.

[0119] Fourth exemplary method

[0120] Figure 8 This is a simplified flowchart of a high-output 3D printing method, generally represented as 900, according to some exemplary embodiments of the present invention.

[0121] The depicted exemplary FDM printing method 900 includes: depositing 1000 grams of thermoplastic polymer 910 from a single printhead having a nozzle with a diameter of 0.4 mm to 0.8 mm within 24 hours using a filament feed of 1.75 mm diameter. According to various exemplary embodiments of the invention, the amount of deposited material is 1100 g, 1200 g, 1300 g, 1400 g, 1500 g, 1600 g, 1700 g, 1800 g, 1900 g, 2000 g, 2100 g, 2200 g, 2300 g, 2400 g, 2500 g, 2600 g, 2700 g, 2800 g, 2900 g, 3000 g, or an intermediate or larger amount. In some embodiments, method 900 includes printing 910 with at least two colors and / or printing 912 with at least four colors. Alternatively or additionally, in some embodiments, method 900 includes and / or operates via a single controller 930 at least two of the individual printheads and / or operates via a single controller 934 at least four of the individual printheads and / or operates via a single controller 936 at least eight of the individual printheads.

[0122] The various production parameters described above for reducing vibration and / or improving accuracy each contribute to high output rates. These parameters include the shortest travel path (see Figure 5 and description), the motor on the print head (see...). Figure 1 (and accompanying instructions), induction heating (see) Figure 2B (and accompanying instructions) and the use of parallel axes (see [reference]). Figure 1 (and accompanying instructions).

[0123] Exemplary connector component

[0124] Figure 3A It is a transverse cross-section of a conduit connector having two push-fit connectors, generally represented as 300 according to some exemplary embodiments of the present invention.

[0125] Figure 3B It is a transverse cross-section of a conduit connector having four push-fit connectors, generally represented as 302 according to some exemplary embodiments of the present invention.

[0126] Some exemplary embodiments of the present invention relate to connector assemblies (e.g., 300 or 302) including a cover 113 having an inner cavity 316 and a conduit 314 through the cavity 316. At least two push-fit connectors 310, 312 are connected in series to engage a portion of the conduit 314 and contact the inner wall of the cavity 316. In the depicted embodiment, the cover 113 has a conduit-sized hole 319 on its top surface 318.

[0127] In some embodiments, two, three, four or more push-fit connectors arranged in series are used to secure the conduit 314 to the output port 317 with sufficient force to counteract friction of the filament moving through the conduit 314.

[0128] Figure 3C It is a transverse cross-section of a conduit connector with adhesive, generally represented as 303 according to some exemplary embodiments of the present invention.

[0129] Some exemplary embodiments of the present invention relate to a connector assembly 303, which includes: a cover 113 having an inner cavity 316 filled with an adhesive 315; and a conduit 314 passing through the cavity 316. In the depicted embodiment, the cover 113 has a conduit-sized hole 319 on its top surface 318.

[0130] In some embodiments, adhesive 315 is used to secure the conduit 314 to the output port 317 with sufficient force to counteract friction from the filament moving through the conduit 314.

[0131] Exemplary silk material

[0132] For the purposes of this specification and the appended claims, the term "filament" includes thermoplastic polymers and / or metals. Thermoplastic polymers include, but are not limited to, PP and / or PS and / or PEKK and / or PLA and / or PEEK and / or PPS and / or PA6 and / or PA12 and / or PC and / or TPU and / or TPE and / or ABS and / or ASA and / or PET-G and / or combinations thereof. Metals include, but are not limited to, copper and / or aluminum and / or lead and / or tin and / or gold and / or platinum and / or titanium and / or stainless steel and / or alloys thereof.

[0133] Exemplary vertical displacement mechanism

[0134] Figure 9 This is a schematic front view of a 3D printing system, generally represented as 1000, according to some exemplary embodiments of the present invention. The features described in the context of this drawing relate to... Figure 1 and / or Figure 6 C and / or Figure 8 The features described in the context are supplemented and can be implemented in the context of system 100 and / or 602 and / or 800.

[0135] As in the previous figures, 130 represents the support frame, 112 represents the feed mechanism on the first support rod 110, and 122 represents the printhead on the second support rod 120. The controller is indicated as 128, but is also indicated as 670 and / or 828.

[0136] In some embodiments, system 1000 includes a vertical shifting mechanism 1012 (symbolically indicated as a double-headed arrow) for object stage 1010. According to these embodiments, when an object being printed by printhead 122 increases in height, mechanism 1012 lowers stage 1010 to facilitate additional printing. Mechanism 1012 is coordinated and controlled by controller 128. The coordinated control is as described above.

[0137] In some embodiments, system 1000 includes vertical displacement mechanisms 1100 and 1200 (symbolically indicated as double-headed arrows) for support rods 110 and 120, respectively. According to these embodiments, as the object being printed by printhead 122 increases in height, displacement mechanisms 1100 and 1200 raise support rods 110 and 120, respectively, to facilitate additional printing. Mechanisms 1012, 1100, and 1200 are coordinated and controlled by controller 128. The coordinated control is as described above.

[0138] According to various exemplary embodiments of the present invention, the vertical displacement mechanism 1012 and / or 1100 and / or 1200 includes a belt drive transmission system (see...). Figure 4A(and Figure 4B and accompanying description) and / or ball screw drive system (see Figure 4B and accompanying description) and / or ball screw drive system (see Figure 4B and accompanying description) Figure 4C and Figure 4D (and accompanying description) and / or hydraulic lifting mechanism.

[0139] It is anticipated that many filament materials, printhead types, and drivetrain types will be developed during the term of this patent, and the scope of this invention is intended to a priori include all of these new technologies.

[0140] Although the invention has been described in conjunction with specific embodiments thereof, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be apparent. Therefore, the invention is intended to cover all such alternatives, modifications, and variations falling within the spirit and broad scope of the appended claims.

[0141] Specifically, various numerical indicators have been used. It should be understood that these numerical indicators can, and even further, vary based on various engineering principles, materials, intended uses, and designs incorporated into the various embodiments of the invention. Additionally, components and / or actions belonging to exemplary embodiments of the invention and depicted as single units can be divided into sub-units. Conversely, components and / or actions belonging to exemplary embodiments of the invention and depicted as sub-units / individual actions can be combined into a single unit / action having the described / depicted function.

[0142] Alternatively or additionally, features used to describe a method can be used to characterize a device, and features used to describe a device can be used to characterize a method.

[0143] It should also be understood that the various features described above can be combined in all possible combinations and sub-combinations to produce additional embodiments of the invention. The examples given above are exemplary in nature and are not intended to limit the scope of the invention as defined solely by the appended claims.

[0144] Each description of an embodiment of the invention, including a specific feature, part, component, module, or process, is an explicit statement that other embodiments of the invention exist that do not include the stated feature, part, component, module, or process.

[0145] Alternatively or additionally, various exemplary embodiments of the present invention exclude any particular feature, portion, component, module, process, or element not specifically disclosed herein.

[0146] Specifically, the embodiments of the present invention have been described in the context of FDM printing, but can also be used in other additive manufacturing solutions.

[0147] All publications, references, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety, to the same extent that each individual publication, patent, or patent application is specifically and individually indicated as being incorporated herein by reference. Furthermore, any reference or designation in this application should not be construed as an admission that such reference is prior art to the invention.

[0148] The terms “including” and “having” and their cognates used in this article mean “including but not necessarily limited to”.

Claims

1. A 3D printer, comprising: (a) A plurality of feed mechanisms, each feed mechanism including a drive motor adapted to push a solid filament through a feed guide; (b) A wire splitter, the wire splitter comprising: Multiple filament inlet ports, each filament inlet port being connected to one of the feed conduits and adapted to receive the solid filament from one of the feed mechanisms; Multiple wire guides, each wire guide connected to the wire inlet port; and A printhead connector, wherein the plurality of filament guides converge at the printhead connector; (c) A printhead attached to the printhead connector, the printhead being configured to feed the solid filament from a feed mechanism operated in the feed mechanism; (d) A pulling motor adapted to pull the filament and guide the filament to a heating block in fluid communication with the printing nozzle; (e) A variable tension mechanism configured to adjust the tension of a single solid filament; (f) A controller configured to coordinately operate each of the push motor, the pull motor, the printing nozzle, and the variable tension mechanism; and (g) A current sensor located on the pull motor, the current sensor being configured to provide an output signal to the controller, thereby the controller adjusting the variable tension mechanism in response to the output signal.

2. The 3D printer according to claim 1, comprising: The first support rod, and the feeding mechanism is mounted on the first support rod; as well as The second support rod, on which the print head is mounted.

3. The 3D printer according to claim 1 or 2, wherein, At least one of the feeding mechanisms includes two or more push-fit connectors mounted in series to lock the end of the feed conduit to the output port of the feeding mechanism.

4. The 3D printer according to claim 1, wherein, The plurality of solid filaments include filaments of different colors, filaments of different materials, or any combination thereof.

5. A 3D printer, comprising: (a) A first support rod on which one or more feed mechanisms are mounted, the first support rod being operably connected to a first drive system configured to provide linear motion in two directions along a single axis to the one or more feed mechanisms; (b) A second support rod on which a printhead is mounted, the second support rod being operably connected to a second drive system configured to provide linear movement to the printhead in two directions on a single axis parallel to the single axis of the first drive system; (c) A third drive system configured to provide parallel linear motion of the printhead relative to the second support rod in two directions; (d) One or more feed conduits connecting the one or more feed mechanisms to the printhead; and (e) A controller configured to operate the first drivetrain, the second drivetrain, and the third drivetrain. The controller is configured to control the first drive system to maintain a distance between the one or more feed mechanisms and the print head, such that the length of the one or more conduits between the one or more feed mechanisms and the print head does not exceed the length of the print head during the operational movement of the print head via the second drive system.

6. The 3D printer of claim 5, comprising two or more feed mechanisms connected to the print head via the same number of conduits, and the controller configured to operate the two or more feed mechanisms.

7. The 3D printer of claim 5 or 6, further comprising a fourth drive system configured to provide parallel linear motion of the one or more feed mechanisms relative to the first support rod in two directions.

8. The 3D printer of claim 7, wherein the controller is further configured to coordinate the operation of the fourth drive system.

9. The 3D printer of claim 6, wherein the controller is configured to operate a single feed mechanism at a time according to a specified color in the program file of the object being printed.

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