This application generally refers to build plates for additive manufacturing. More specifically, the application relates to methods and apparatus for producing a tight tolerance building platform for additive manufacturing.
Additive manufacturing is a process by which a product or part is manufactured by adding material progressively to the base printed structure in a sequence or pattern that would result in a solid part being built. This method of manufacturing is commonly referred to as three dimensional or 3-D printing and can be done with various materials, including but not limited to plastics and metals.
3-D printing machines utilize a build plate to act as a base for printing the desired part. The feed material is placed or printed onto the build plate in sequential beads or dots which builds into sequential layers. 3D printers, including metal and polymer printers, require a smooth and flat surface to start each new print. Metal 3D printers use a metallic build plate that is typically CNC machined to achieve the appropriate surface finish (smoothness) and flatness.
The inventors discovered that, as the size or print diameter of a metal 3D printer increases, traditional CNC machining of the build plate to achieve the required surface finish and flatness becomes infeasible. Determining how to achieve the required flatness and surface finish without the aid of classic CNC machines represents a key challenge to scaling up metal 3D printer systems.
Embodiments of the invention include a metal 3D printing build plate system and methodology that allows for printing metal structures up to 18 feet in diameter or larger. The systems and methods do not rely on traditional CNC machining and instead use the machining capabilities of a 3D metal printing robot to achieve the required surface finish and flatness on a reusable build plate. In this regard, the scale of the build plate is constrained only by the reach of the print cell robot.
In some embodiments, the base of the build plate is constructed as a large-welded assembly with loose control over the flatness and smoothness of the outward facing surface (upon which a 3d printed structure is deposited). A reusable build plate is then mounted onto the base plate (the large welded assembly). The reusable build plate comprises multiple smaller CNC machined sections that, when assembled, form an annular metal surface. Embodiments can then leverage the in-cell CNC machining capabilities of the metal 3D printer robots to final machine the reusable build plate to the required surface finish and flatness, which may be verified by a laser scanner or dial indicator.
At the conclusion of a print operation, the robot can machine the base of the completed part to separate it from the build plate. The robot can then machine the excess material from the previous part away from the reusable build plate and prepare the surface for the next operation.
The innovative build plate methods and systems described in this specification can remove the dimensional constraints associated with traditional CNC machines and enable construction of larger-scale metal 3D printer systems. Certain embodiments can increase the speed of print cell construction and part production by not needing to rely on large-scale external machining operations for build plate construction or between print operations.
In some embodiments, the techniques described herein relate to a printing build plate including: a plurality of build plate assemblies, wherein each of the build plate assemblies further includes; and a plurality of build support structures, wherein each of the build support structures is configured to support a build support device on at least a portion of the build support structure and wherein, the build support device is configured to support a machinable build plate attached to the build support device such that an outer surface of the machinable build plate can be machined to an acceptable flatness tolerance; and wherein each of the plurality of build plate assemblies are connected to form a build plate volume wherein a 3-D printed part can be produces on the machinable build plate.
In some embodiments, the techniques described herein relate to a method for producing a printing build plate including: obtaining a plurality build support devices; obtaining a plurality of build support structures; obtaining a plurality of machinable build plates; assembling a plurality of build plate assemblies, wherein each of the plurality of build plate assemblies includes at least one build support structure connected to at least one of the plurality of build support devices, and wherein at least one of the plurality of machinable build plates is attached to the at least one build support device; and machining an outer surface of the machinable build plate to an acceptable tolerance.
Some embodiments relate to an additive manufacturing build plate. In an embodiment, the build plate includes: a build structure with a first planar tolerance; and a plurality of build plate assemblies, wherein each build plate assembly includes: a build support device, the build support device affixed to the build structure; and a machinable build block coupled to the build support device, the machinable build block configured such that an outer surface of the machinable build block is capable of being machined to a second planar tolerance, the second planar tolerance is more precise than the first planar tolerance; wherein each of the plurality of build plate assemblies are connected to form a build plate surface, and wherein the build plate surface is suitable for an additively manufactured part to be produced on the plurality of machinable build blocks.
In a further embodiment, the machinable build block includes a top surface configured to conform to a bottom surface of a desired article.
In another further embodiment, the machinable build block is coupled using mechanical fasteners to the build support device.
In a yet further embodiment, the mechanical fasteners are recessed from a top surface of the machinable build block.
In a still further embodiment, the machinable build block includes reference features capable of being used as a datum for an additive manufacturing process.
Some embodiments relate to a method for producing an additively manufactured article. In an embodiment, the method includes: obtaining a build structure; obtaining a plurality of build plate assemblies; wherein each build plate assembly among the plurality of build plate assemblies each includes a machinable build block; coupling the plurality of build plate assemblies to the build structure; machining an outer surface of at least one machinable build block to a first configuration with a first desired planar tolerance; additively manufacturing a first article at a first orientation on the outer surface of the at least one machinable build block; removing the first article from the machinable build block and machining the outer surface of the at least one machinable build block to a second configuration with a second desired planar tolerance, the second configuration different from the first configuration; and coupling the first article to the build structure in a second orientation and additively manufacturing a second article onto the first article.
In yet another embodiment, coupling the plurality of build plate assemblies is performed using mechanical fasteners.
In still another embodiment, the first configuration conforms to a desired bottom surface of the first article.
In another embodiment again, the second configuration includes reference features for aligning the first article when the first article is coupled to the build structure in a second orientation.
In still yet another embodiment, the first article includes first alignment features, and the second configuration of the machinable build block includes second alignment features corresponding to the first alignment features when the first article is coupled to the build structure in the second orientation.
In still another embodiment again, the machinable build block includes reference features capable of being used as a datum for an additive manufacturing process.
Some embodiments, relate to a method for producing an additively manufactured article. In an embodiment the method includes: obtaining a build structure; obtaining a plurality of build plate assemblies; wherein each build plate assembly from among the plurality of build plate assemblies includes a machinable build block; coupling the plurality of build plate assemblies to the build structure; machining an outer surface of at least one machinable build block to a first configuration with a first desired planar tolerance; and additively manufacturing a first article at a first orientation on the outer surface of the at least one machinable build block.
In another further embodiment, coupling the plurality of build plate assemblies is performed using at least one mechanical fasteners.
In yet another further embodiment, the first configuration conforms to a desired bottom surface of the first article.
In still another further embodiment, the machinable build block includes reference features capable of being used as a datum for an additive manufacturing process.
In another further embodiment again, removing the article from the machinable build block and machining the outer surface of the at least one machinable build block to a second configuration with a second desired planar tolerance, the second configuration different from the first configuration.
In yet still another further embodiment, coupling the article to the build structure in a second orientation and additively manufacturing a second article onto the first article.
In yet still another further embodiment again, a second configuration includes reference features for aligning the first article when the first article is coupled to the build structure in a second orientation.
In another further additional embodiment, a top of the at least one mechanical fastener is below a top surface of the machinable build block.
In another further additional embodiment again, the first article includes first alignment features, and the second configuration of the machinable build block includes second alignment features corresponding to the first alignment features when the first article is coupled to the build structure in a second orientation.
Additional embodiments and features are set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the specification or may be learned by the practice of the disclosure. A further understanding of the nature and advantages of the present disclosure may be realized by reference to the remaining portions of the specification and the drawings, which forms a part of this disclosure.
The description will be more fully understood with reference to the following figures, which are presented as embodiments of the invention and should not be construed as a complete recitation of the scope of the invention, wherein:
Systems and methods for producing a smooth and flat metal printing build plate for a 3-D printer are described herein. Such systems and methods can beneficially be used with a large-scale 3-D printer, such as a horizontally oriented 3d metal printer. Many embodiments are directed to a plurality of metallic support elements fixed to a base plate. Each of the plurality of metallic elements can be connected to the base plate through one or more fasteners. The various support elements can be assembled in a manner that creates a solid surface upon which a 3-D metallic part can be printed. In many embodiments, the support elements have a build block element connected thereto. The build block element has a portion or surface that can be machined to a planar tolerance that is sufficient to produce a printed 3-D metallic part without negative effects on the build. In other words, the printed part can be built without significant deviations to the design which would allow for more precise parts to be built.
The inventors recognized that, in order to produce high quality parts, the build plate needs to be level with respect to the print direction axis. They further recognized that, depending on the material and the part being built, the levelness of the build plate may require tight tolerances. They recognized that, if the build plate print surface is not level and within the desired tolerances, then the print can be defective in the build resulting in wasted materials. Accordingly, they recognized the advantage in building build plates and the underlying build support structure elements with tight tolerances. This often does not present issues with smaller parts. But, they realized that the larger the part and build support structure, the more difficult and expensive the various build structure elements and build plate will be to manufacture because it becomes more difficult and time consuming to maintain the tight tolerances required for building large complex parts.
Traditional 3-D printed parts require the use of a level or flat build surface (e.g., on the order of 0.050″ and often less than 0.030″) to be able to print the part. 3-D printing is also referred to as additive manufacturing, in which layers are added onto a previously applied layer. The inventors recognized that having a precision build surface is extremely important. They recognized that, if the first layer deviates from a specified planar tolerance, then subsequent layers will also deviate, leading to a final part that may deviate from the build plane significantly at its extremis. This is especially true when printing larger parts with a finished end that is located a long distance (e.g., 18 feet or more) away from the printing surface. It is recognized that small deviations in the first few layers can lead to a tolerance stack up that results in a large deviation at the finished end, which can render the part unusable. Accordingly, the inventors recognized the need for 3-D printers with a build surface that defines a flat plane within a high tolerance. Existing implementations of table-top style printers did not solve this need. With smaller table-top style printers that are designed to produce small parts, the planar tolerance required is generally not as exacting. Additionally, smaller table-top style printers naturally require less time and effort to achieve the required tolerance. Furthermore, such smaller surfaces are relatively inexpensive to produce and easily replaceable.
In contrast to prior methods of making monolithic build surfaces, many embodiments are directed to multi-component building surfaces. In various embodiments, these building surfaces are capable of being used to perform multiple prints. Desirably, when a building surface has been consumed (e.g., reused until depleted), it can be swapped out with a new building surface while most of the build continues to be reusable. In many embodiments, the tolerance of the build surface may be efficiently produced by machining the build surface using standard machining robots. Moreover, this process can be repeated to ensure the planar tolerance of the build plate is maintained over different prints.
Finally, the multiple components comprising the machinable build plate assembly allow for individual parts of the build plate assembly to be changed out independently as necessary. Embodiments also allow the printer to machine the print surface based on specific print parameters and thus prevent the need to make additional adjustments once the build surface has been installed. Furthermore, in many embodiments the adaptability and ease of configuration of the multiple component build plate allow for printed components to be removed then reattached and machined to a desired configuration and/or part tolerance.
In order to help reduce the overall cost and complexity of producing tight tolerances on build surfaces, many embodiments are directed to a multi-component build plate assembly that can be custom designed and built to any number of sizes to produce a large variety of 3-D printed parts. Furthermore, such embodiments allow for precision parts to be produced in non-traditional build volumes such as horizontally-extending build volumes vs. a more conventional vertically-extending build volume. Methods and systems for performing horizontal additive manufacturing are described in U.S. Provisional Patent Application No. 63/369,904, incorporated by reference in its entirety. Methods and systems for additive manufacturing build plates are described in U.S. Provisional Patent Application No. 63/368,609, incorporated by reference in its entirety.
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For example, some embodiments may include a circular build plate with multiple build plate assemblies connected in such a fashion that it produces an overall circular build plate. An example circular build plate is conceptually illustrated in
Because the final built product (e.g., the article of manufacture) may require a high level of precision, it can be beneficial to mount a building block (e.g., the building block 102) on a build support device (e.g., a build support device 118). Beneficially, the building block positioning can be finely adjusted relative to the build support device 118 prior to and/or during mounting the building block 102 to the build support device 118. It can be appreciated that the build support structure 104 can have a build support device 118 connected to the build structure 104 on a portion thereof. In some embodiments, the build support device 118 can be attached to an outer portion or a section of the build structure 104 that is near an outer edge of the build structure 104, as shown in
Building blocks (e.g., reusable custom build plates) can be mounted to permanent build support structures (e.g., horizontal build plate structures, build support structure 104). The building blocks can be machined in-place prior to use in order to provide the appropriate surface conditions in accordance with several embodiments.
In addition to the build support structures, a build plate can include several machined parts and can be designed to be assembled in accordance with some embodiments. Building blocks can be divided into multiple sections to make machining accessible. In some embodiments, the building blocks can be divided into at least 2 pieces; at least 4 pieces; at least 6 pieces; at least 8 pieces; and at least 10 pieces.
Build plates can have machining capabilities. Some embodiments mitigate risks by machining a flat surface into a support structure (e.g., an aluminum support structure), and then placing a disposable aluminum build block as a working surface into that groove. The reusable support structures can be made with 6XXX series aluminum alloys, and can be about 2 inch in thickness. The disposable build blocks can be made with 5XXX series aluminum alloys. Aluminum sections (e.g., build blocks) can be bolted to the support structure to form the working surface. Some embodiments can use in cell machining capability and/or bring in machining capability to machine the plate assembly flat relative to the print head reference. Certain embodiments may use same machining to place concentric step features, datums and tamper guide pins. These additional features may assist part re-install and part flip operations. In a number of embodiments, the machined surface can support direct cartridge printing and/or build plate install.
In several embodiments, build support devices can be attached to a top surface of a support structure. Build support devices in conjunction with building blocks can provide a means to adjust the position of a build surface finely.
A build support device 200 (e.g., the build support device having similarities to build support device 118 in
The build support device 200 illustrated in
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As can be fully appreciated, the process of building and machining the build plate, in accordance with many embodiments, can be applicable to any form of 3-D printing. For example, some embodiments may use the configurable and machinable build plate for vertical 3-D printing while other embodiments can take advantage of the adaptability to produce parts on a horizontal 3-D printing machine. Given the customizable nature of 3-D printing, it can be appreciated that the adaptability and ease of manufacture of the build plates described herein can be highly advantageous in printing large complex structures that would not otherwise be capable using more traditional methods and tools. The inventors realized that the process of building and machining the build plate discussed herein has particular utility in wire-arc additive manufacturing or other 3D printing technologies where the diameter of the build plate is greater than at least 50 inches; at least 55 inches; at least 1 foot; at least 5 feet; at least 10 feet; at least 15 feet; at least 20 feet; or at least 25 feet.
In addition, it can be appreciated that the customizable nature of the build plate assembly allows the re-installation of previously printed parts for further supplemental printing or manufacturing as required by utilizing custom machined entities for installation and alignment easy.
This description of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, and modifications and variations are possible in light of the teachings above. The embodiments were chosen and described to explain the principles of the invention and its practical applications. This description will enable others skilled in the art to best utilize and practice the invention in various embodiments and with various modifications as are suited to a particular use. The scope of the invention is defined by the following claims.
This application claims the benefit of, and incorporates by reference, U.S. Provisional Patent Application No. 63/369,904, filed Jul. 29, 2022. This application also claims the benefit of, and incorporates by reference, U.S. Provisional Patent Application No. 63/368,609, entitled “Systems for Horizontal Wire Arc Additive Manufacturing and Methods Thereof,” filed Jul. 15, 2022.
Number | Date | Country | |
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63369904 | Jul 2022 | US | |
63368609 | Jul 2022 | US |