Rotational stereolithography for arched 3D objects

Abstract

The three-dimensional (3D) printing system is configured to manufacture multiple arched 3D articles. The 3D printing system includes a build vessel, at least one build assembly, a light engine, and a controller. The at least one build assembly individually includes an axis, a build plate, and a motorized gear assembly. The motorized gear assembly is connected to the axis and configured to rotate and position the axis around the rotation axis. The light engine is located above the build vessel. The controller is configured to operate the motorized gear assembly to rotate the build plate progressively around the rotation axis between multiple stop positions. The controller is configured to operate the light engine at each stop position to selectively irradiate a photocurable liquid within multiple spatially separated build planes, each located above one of the multiple build plates.

Description

Cross - reference to related applications

[0001] This non - provisional patent application claims priority to U.S. Provisional Patent Application No. 63 / 496,752, filed Apr. 18, 2023, by Colin Leonard Blain, entitled "Rotational Stereolithography for Arcuate 3D Articles", which is incorporated herein by reference under 35 U.S.C. 119(e).

Technical Field

[0002] The present disclosure relates to an apparatus and method for manufacturing three - dimensional (3D) articles from a photocurable liquid in a layer - by - layer manner. More particularly, the present disclosure relates to a method for simultaneously manufacturing a plurality of customized arcuate - shaped articles using a relatively small and simple apparatus.

Background Art

[0003] Three - dimensional (3D) printers are being used increasingly rapidly to manufacture customized 3D articles. One type of 3D printer includes stereolithography printers that have the basic principle of operation involving the selective curing and solidification of radiation - curable (i.e., photocurable) liquids. 3D articles are formed in a layer - by - layer manner. One substantial use of this technology is the fabrication of customized arcuate objects such as dental arches and retainers.

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is desirable to improve productivity for this type of application.

Means for Solving the Problems

[0005] In a first aspect of this disclosure, a three-dimensional (3D) printing system is configured to manufacture a plurality of arched 3D articles. "Arched" means that the 3D articles may have an arched geometric shape, such as a circular, elliptical, or arched geometric shape or form. The arched shape may have some degree of asymmetry or irregularity. An example of an arched shape is a dental arch. The 3D printing system includes a build vessel, at least one build assembly, a light engine, and a controller. The build vessel is configured to contain a photocurable liquid having an upper liquid surface. The at least one build assembly includes, individually, an axis, a build plate, and a rotational motion mechanism. The axis has a horizontal rotation axis X. The build plate is mounted on the axis and extends radially from the axis. The build plate has an upper surface. The rotational motion mechanism is connected to the axis and configured to rotate and position the axis around the rotation axis X. The light engine is located above the build vessel. The controller is configured to operate a rotational movement mechanism to gradually rotate the build plate around a rotation axis between stopping positions. Between each stopping position, the controller is configured to operate a light engine to selectively irradiate a photocurable liquid within multiple spatially separated build planes to selectively cure a slice of one of the multiple arched 3D articles.

[0006] Arch-shaped objects, particularly dental arches, represent a primary application of 3D printing. Compared to conventional systems, this device is extremely compact and highly volume-efficient. Having a smaller system that offers the same functionality is advantageous in dental laboratories where physical space is precious. Furthermore, photocurable resins are very expensive and have a limited lifespan after being placed in the production vat. Therefore, smaller volume requirements reduce operating costs.

[0007] In one implementation configuration, at least one build assembly includes multiple build assemblies arranged along a horizontal axis Y perpendicular to the rotation axis X. These multiple build assemblies are individually spread across most or all of the width of the build container along the X axis.

[0008] In another implementation, the build plate extends individually from the rotation axis X along the radial axis r. Each slice of the arched 3D object has a trapezoidal cross-section, which has two parallel bases with base dimensions proportional to the radial position.

[0009] In various mounting configurations, the slice thickness can vary from 0.05 mm to 0.2 mm, or from 0.1 mm to 0.2 mm. Further thickness ranges are also possible.

[0010] In yet another implementation, a method for manufacturing multiple arched 3D articles includes the steps of: rotating and positioning multiple build plates, each having an arched 3D article top surface, one layer below the top surface of the photocurable liquid; and operating a light engine to selectively irradiate multiple spatially separated build planes, each individually aligned with the top surface of the arched 3D article, to cure and solidify slices of the photocurable liquid onto the top surface of the arched 3D article. The slices of the photocurable liquid have a variable thickness proportional to the distance from the rotation axis X.

[0011] In a second aspect of this disclosure, a method for manufacturing an arched three-dimensional (3D) article comprises the steps of: (1) providing a 3D model of the arched 3D article; (2) slicing the 3D model using an axial region below the vertices of the arched 3D article or a set of slice planes diffusing from the axis; (3) rotating the top surface of a build plate or a partially completed portion of the arched article around a specific position to provide a layer of photocurable liquid above the top surface; (4) operating a photoengine to selectively cure the layer of photocurable liquid on the top surface to form a new top surface; and (5) repeating the rotation and operation of the photoengine to complete the manufacturing of an arched 3D article from a series of variable-thickness slices, each slice having a thickness that increases with distance from the axial region.

[0012] In one implementation configuration, the arched 3D article includes a dental arch. The arched 3D article may also include a support structure configured to connect one end of the dental arch to the upper surface of the build plate.

[0013] In another implementation, the slicing planes diverge from an axis located below the vertices of the 3D model. This axis can be the rotation axis of the build plate. The slicing process includes forming a stack of slices having a thickness proportional to the radial distance from the axis.

[0014] In a third aspect of this disclosure, a method for manufacturing a plurality of arched three-dimensional articles comprises the following steps (1) to (4): Step (1) is the step of providing a 3D printing system comprising a build container, a build assembly, and a light engine. The build container is configured to contain a photocurable liquid having an upper surface. The build assembly comprises a machine axis having a horizontal rotation axis X, a build plate attached to the machine axis that extends radially from the machine axis and has an upper surface, and a rotational motion mechanism coupled to the machine axis that is configured to rotate and position the machine axis around the rotation axis X. The light engine is located above the build container. Step (2) is the step of operating the rotational motion mechanism to position the individual upper surfaces of the plurality of arched three-dimensional articles at a position one layer thickness below the upper surface of the photocurable liquid. The layer thickness changes linearly along the radius extending from the rotation axis of the machine axis. Step (3) includes operating a light engine to selectively irradiate multiple build planes corresponding to multiple arc-shaped three-dimensional (3D) articles, and curing trapezoidal slices of photocurable liquid on the top surface. Step (4) includes repeating steps (2) and (3) to complete the creation of multiple arc-shaped three-dimensional articles. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic side cross-sectional view of one embodiment of a 3D printing system (the Y-axis and Z-axis are horizontal and vertical, respectively). [Figure 2A] This is a schematic plan view of one embodiment of a 3D printing system (X and Y are orthogonal horizontal axes). [Figure 2B] This is a schematic top view of one embodiment of a 3D printing system (X and Y are orthogonal horizontal axes). [Figure 3]A flowchart showing an embodiment of a method for manufacturing a plurality of arcuate 3D articles. [Figure 4A] A schematic side view of a single shaping platform that is firmly attached to a spindle and enables the spindle to rotationally tilt the shaping platform. This shows the initial state before a layer or slice of photocurable liquid is cured on the shaping platform. [Figure 4B] A view different from FIG. 4A in that a first layer or slice of photocurable liquid is selectively cured on the shaping platform. [Figure 4C] A view different from FIG. 4B in that a second layer or slice of photocurable liquid is selectively cured on the first layer or slice of cured photocurable liquid. The second slice has a trapezoidal shape because the upper surface of the first slice is cured at an oblique angle within the photocurable liquid. [Figure 4D] A view different from FIG. 4C in that a third layer or slice of photocurable liquid is selectively cured on the second layer or slice of cured photocurable liquid. [Figure 5] A flowchart showing an embodiment of a method for manufacturing an arcuate 3D article. [Figure 6A] Showing slices of an arcuate 3D article using a series of diffusing slice planes. [Figure 6B] Showing the solidification of the first slice of the arcuate 3D article. [Figure 6C] Showing the solidification of the second slice of the arcuate 3D article. [Figure 6D] Showing the progress of the solidification of the arcuate 3D article. [Figure 7] Showing a dental arch and a support as an example of an arcuate 3D article. [Figure 8] A schematic view showing another embodiment of an arcuate 3D article with respect to the axis of rotation.

Embodiments for Carrying Out the Invention

[0016] FIG. 1 is a schematic side cross-sectional view of a 3D printing system 2 for fabricating a plurality of customized arcuate 3D articles 3 each having an arcuate shape. In the context of the present disclosure, arcuate can refer to a semi-circular, elliptical, hyperbolic, parabolic, or arch-like shape. In some cases, the arcuate shape can be somewhat asymmetric or irregular. When describing the 3D printing system, axes X, Y, Z that are orthogonal to each other can be used. The X-axis and Y-axis are generally horizontal transverse axes. The Z-axis is a vertical axis generally aligned with the gravity reference. In the use of the term "generally", it is suggested that the quantity or characteristic is by design but may not be exact.

[0017] The 3D printing system 2 includes a forming container 4 configured to contain a photo-curable liquid 6. The photo-curable liquid 6 can be cured and solidified by radiation in the blue to ultraviolet wavelength or about 500 nanometers (nm) to 100 nm. The photo-curable liquid 6 can be a photo-curable resin that can contain various components including monomers and photo-initiators or catalysts. When exposed to radiation having an appropriate wavelength in the blue to ultraviolet wavelength, the photo-initiator or catalyst initiates the polymerization and / or cross-linking of the monomers to form a solid. Photo-curable liquids and resins are known in the technical field of stereolithography.

[0018] At least one forming assembly 8 is attached to the forming container 4. The forming assembly 8 includes at least one forming plate 10 connected to a (motor) spindle 12. The forming plate 10 has a forming surface 14 on which one end 15 of the 3D article 3 is formed. During the formation of the 3D article 3, the spindle 12 rotates the forming plate through the photo-curable liquid 6. Different orientations of the forming plate 10 during the formation of the 3D article 3 are shown by dashed lines in FIG. 1.

[0019] In the illustrated embodiment, multiple axes 12 individually position multiple build plates 10. In the initial position, a thin layer of photocurable liquid 6 is present on the build surface 14 on the build plane 18. Thus, the illustrated embodiment includes a two-dimensional array or multiple build planes 18. The build planes 18 can "move laterally" as the manufacturing of the arched 3D article 3 progresses.

[0020] The optical engine 16 is configured to selectively supply radiation to an array on the build plane 18, selectively curing and solidifying thin layers of photocurable resin 6. In the first embodiment, the optical engine 16 includes a laser, a scanner, and a projection optical system. The scanner is a two-dimensional scanner, such as a series of galvanometer mirrors including X and Y mirrors. A light beam from the laser passes through the scanner and is focused onto an array on the build plane 18 by the projection optical system. The X and Y mirrors scan the beam laterally on the build plane 18 along the X and Y axes, respectively. The optical engine according to the first embodiment is known in the art of stereolithography.

[0021] In the second embodiment, the optical engine 16 includes a light source, a micromirror array, and a projection optical system. The light source illuminates the micromirror array. The micromirror array has a two-dimensional array of micromechanical mirrors, which can individually switch between transmitting the optical pixel beam through the projection optical system to the build plane 18 or to an "optical trap" that absorbs light. As a result, selective projection of radiated pixels on the build plane 18 is obtained. The optical engine according to the second embodiment is also known in the art of stereolithography.

[0022] In a third embodiment, the optical engine 16 may include a “light bar” that scans the build plane. The light bar may include an array of light-emitting devices that are “on” and “off” during scanning, selectively illuminating pixels on the build plane. Further embodiments of the optical engine 16 may use various components as scanning devices, such as a rotating polygon mirror.

[0023] The controller 20 is connected to the motor shaft 12 and the optical engine 16. The controller 20 includes a processor 22 coupled to an information storage device 24. The information storage device 24 includes a non-volatile or non-temporary storage medium for storing software instructions. The non-volatile or non-temporary storage medium may include one or more of a magnetic disk drive and flash memory. When executed by the processor 22, the software instructions can operate the motor to rotate the shaft 12 and operate the optical engine 16.

[0024] Controller 20 can be a single computer controller installed in the same location as the other components of the 3D printing system 2. Alternatively, controller 20 can include multiple computer controllers that can be installed in the same location as the other components of system 2, installed separately, or installed remotely. Thus, controller 20 can include one or more of the following: microcontrollers, desktop computers, laptop computers, computer servers, or other computing devices known in the fields of computer science and engineering.

[0025] Figure 2A is a schematic plan view of the 3D printing system 2. In the illustrated embodiment, two axes 12 each support six build plates 10, for a total of twelve build plates 10. The illustrated configuration makes it possible to simultaneously manufacture twelve (or possibly more) customized arched 3D articles 3. In the illustrated embodiment, the optical engine 16 is configured to project a two-dimensional array of twelve build planes 18, each corresponding to an individual build plate 10. The axes 12 are individually connected to a rotary movement mechanism 26. The rotary movement mechanism may be an electric gear assembly 26.

[0026] It should be understood that the number of two axes 12, each having six build plates 10, as shown in the figure, is just one of many possible configurations. In other embodiments, one axis 12 can support two or more build plates. The axis 12 can support and rotate three, four, five, six, seven, eight, nine, ten, or more build plates 10. The number of axes can be three, four, five, six, seven, or more axes 12.

[0027] In the illustrated embodiment, the electric gear assembly 26 includes a stepping motor coupled to a "gear train." The gear train is a series of gears configured to achieve appropriate gear reduction between the stepping motor and the machine shaft 12. Such motors and gear assemblies are known in the art for highly precise rotational positioning control. Other motors, such as servo motors, are also conceivable. Such motors and gear trains for incremental motion control (motion in rotational steps) are known in the art for various applications, such as in the printing industry.

[0028] Figure 2B is similar to Figure 2A, except that a single build plate 10 is along and extends from the axis 12. In other respects, the components of Figure 2B are the same as those of Figure 2A in function and configuration. The optical engine 16 can define multiple or linear arrays of laterally spaced build planes 18 on the build plate 10.

[0029] Figure 3 is a flowchart of a method 30 for manufacturing multiple arched 3D articles 3. Method 30 is carried out by a controller 20 acting on an electric gear assembly 26 and an optical engine 16. According to 32, the axis 12 is rotated and positioned so that the build plate 10 is positioned above the surface of the photocurable liquid 6 or below the build plane 18. Thus, the upper surface 14 of the build plate 10 is immersed in the photocurable liquid 6.

[0030] According to 34, the axis 12 is rotated so that the layer thickness of the photocurable liquid 6 and the build plane 18 are positioned above the upper surface 14. According to 36, the light engine 16 is activated to selectively irradiate the array of build planes 18, selectively curing and solidifying the layer thickness of the photocurable liquid 6 on the upper surface 14. The cured photocurable liquid or resin 6 defines the upper surface of the slice of the arched 3D article 3.

[0031] According to step 38, the axis rotates and positions the upper surface of the cured resin 6 below the build plane 18 by the thickness of one layer. In an exemplary embodiment, the positioning in step 38 involves a “deep dip” motion in which the axis 12 rotates the upper surface 14 below the build plane 18 by more than the thickness of one layer, and then returns it below the build plane 18 by the thickness of one layer.

[0032] Step 40 is the same as step 36. Steps 38 and 40 are repeated until the arc-shaped 3D article 3 is completed layer by layer.

[0033] Figures 4A-4D illustrate the fabrication of layers or slices of an arched 3D article 3. Figure 4A shows the build plate 10 connected to the machine axis 12 before the slice or layer of the photocurable liquid 6 is cured on the top surface 14. The machine axis 12 has a rotation axis 42 parallel to the X-axis (Figure 2). The radial distance r is defined as the distance along the build plate 10 from the rotation axis 42. The rotation angle from the horizontal can be defined as the angle theta (θ).

[0034] Figure 4B shows a cured slice 44 of the photocurable liquid on the build plate. The slice has a thickness along Z and is bounded laterally by r values ​​R1 and R2. Figure 4B shows the results of steps 34 and 36. The first and subsequent cured slices 44 each have a top surface 46.

[0035] Figure 4C shows steps 38 and 40 for forming the second cured slice 44. Since the photocurable liquid 6 has a depth that increases along the radius r, the cured slice 48 has a trapezoidal cross-section. The base at r=R2 (far from the axis of rotation 42) is greater than the base at r=R1 (closer to the axis of rotation). At any point along the build plate 10, the slice thickness is approximately equal to the radius r multiplied by the change in angle theta (θ) from Figure 4B to Figure 4C. Thus, the base at r=R1 has a height approximately equal to R1 multiplied by the change in angle theta (θ). The base at r=R2 has a height approximately equal to R2 multiplied by the change in angle theta (θ). This generally holds true for each subsequent cured slice 44. Figure 4D shows the third cured slice.

[0036] Figure 5 is a flowchart illustrating an embodiment of method 50 for manufacturing an arched 3D article 3. Compared to method 30 described in relation to Figure 3, method 50 emphasizes the slicing process more. According to 52, a three-dimensional (3D) model of the arched 3D article 3 is provided. The 3D model may be equivalent to a computer-aided design (CAD) file. An example of such an arched 3D article 3 is a dental arch. Optionally, according to 54, a support is added to one end of the arched 3D model 3 for connection to a build plate 10.

[0037] According to 56, the arched 3D model 3 is sliced. The slicing process is performed using a series of slicing planes that diverge from the vertex or the lower axis or axial region of the upper part of the arched 3D model 3. An example of such slicing is shown in Figure 6A. In the illustrated embodiment, the arched 3D article 3 is sliced ​​using a series of slicing planes 62, all of which extend from the rotation axis 42 of the machine axis 12. The first slicing plane 64 extends at an oblique angle to the horizontal X-axis. The rotation axis 42 is located directly below the vertex of the arched 3D article 3. As a result, a series of slices 44 forming the arched 3D article 3 are obtained.

[0038] According to step 58, the slices 44 are rotated, and each of them has a horizontal top surface 46 (Figure 4B) that can coincide with the build plane 18. Steps 56 and 58 can be performed simultaneously or in sequence, so they can be combined; for example, the slicing process may be performed after the 3D article 3 has been rotated, so that each slice 44 has a horizontal top surface 46 during the slicing process.

[0039] Once steps 56 and 58 are completed, a series of slices 44 are obtained for generating the arched 3D article 3 using the 3D printing system 2. There may be a delay between these steps and the physical fabrication in step 60. According to step 60, the 3D printing system 2 is operated to form the physical arched 3D article 3. Step 60 of method 50 is similar to or equivalent to method 30 in Figure 3 illustrating the actual formation. Thus, step 60 is a series of repeatable steps.

[0040] Figures 6B-6D show the selective curing of slices to form a 3D article 3. According to 6B, a first slice 44 is formed. This is achieved by rotating the upper surface of the build plate 14 under the upper surface 66 of the photocurable liquid 6 (Figure 1). The photoengine 16 is then operated to selectively irradiate the build plane 18 and cure the first slice 44 of the 3D article 3.

[0041] Figure 6C is similar to Figure 6B, except that a second slice 68 is formed on top of the first slice 44. The top surface of the first slice 44 is rotated until it is one slice thickness below the top surface 66 of the photocurable liquid. The light engine 16 is then operated to selectively irradiate the build plane 18 to cure and adhere the second slice 44 onto the first slice 44. Figure 6D shows the build plate 10 and the seven slices formed on each other. This process continues until the entire arc-shaped article 3 is manufactured. As previously mentioned, a “deep immersion” motion can be used to facilitate the formation of a new layer of uncured photocurable liquid 6 on top of the top surface 46.

[0042] It should be noted that the slices 44 shown in Figures 6A-D have exaggerated thicknesses for illustrative purposes. In reality, the slices can vary in thickness from 20 to 200 microns, or from 30 to 100 microns. In the exemplary embodiment, the slice is approximately 50 microns thick, but the thickness varies and increases radially from the axis of rotation 42.

[0043] Figure 7 shows a single build plate 10 supporting three arched 3D articles 3. The illustrated arched 3D articles 3 include a dental arch 70. Part of the arched 3D articles 3 is a support structure 72 that functions as a physical interface between the dental arch 70 and the upper surface 14 of the build plate 10.

[0044] In the illustrated embodiment, the arched 3D article 3 is generally symmetrical, and the axis of rotation 42 is aligned laterally with the vertex of the arched 3D article 3, but perpendicularly with the base of the arched 3D article 3 (at the start of printing). However, variations are possible. For example, the axis of rotation may be positioned above or below the base of the arched 3D article 3, or it may be positioned away from the lateral alignment with the vertex of the arched 3D article 3. Also, the arched 3D article may be asymmetrical or somewhat irregular in shape. Therefore, certain figures are shown for illustrative purposes only and are not intended to be limiting.

[0045] Figure 8 is a schematic diagram showing another embodiment of an arched 3D article or dental arch 3 with respect to a rotation axis 42. In this embodiment, the rotation axis 42 is aligned with the vertex 74 along the inclined plane. The fabrication process begins by defining the axis of symmetry of the dental arch 3 at an oblique angle with respect to the fabrication plane 18 and the upper surface 66 of the photocurable liquid 6.

[0046] The specific embodiments and their applications described above are for illustrative purposes only and do not preclude modifications and variations that are included in the appended claims.

Claims

1. A three-dimensional (3D) printing system configured to manufacture multiple arch-shaped 3D objects, A molding container configured to contain a photocurable liquid having an upper surface; At least one build assembly; A light engine located above the aforementioned molded container; and controller Equipped with, Each of the aforementioned molded assemblies is individually, Axle having a horizontal rotation axis X; A molding plate attached to the shaft, extending radially from the shaft and having an upper surface; and A rotational movement mechanism connected to the aforementioned shaft and configured to rotate and position the shaft around the rotation axis X. Includes, The aforementioned controller, The rotational movement mechanism is operated to gradually rotate the molding plate around the rotation axis between a plurality of stopping positions. At each of the multiple stopping positions, the light engine is operated to selectively irradiate the photocurable liquid within multiple spatially separated building planes located on the build plate, thereby selectively curing a slice of one of the multiple arch-shaped 3D articles. A 3D printing system configured as follows.

2. The 3D printing system according to claim 1, characterized in that the at least one build assembly includes a plurality of build assemblies arranged along a horizontal axis Y perpendicular to the rotation axis X.

3. The 3D printing system according to claim 1, characterized in that the molding plate includes a plurality of molding plates spaced apart along the rotation axis X.

4. The 3D printing system according to claim 1, characterized in that the molding plate extends from the rotation axis X along the radial axis r, and each slice of the arch-shaped 3D article has a thickness proportional to r.

5. The 3D printing system according to claim 1, characterized in that the molding plate extends from the rotation axis X along the radial axis r, and each slice of the arched 3D article has a trapezoidal cross-section, which has two parallel bases having base dimensions proportional to the radial position.

6. The 3D printing system according to claim 1, characterized in that the rotational motion mechanism includes an electric gear assembly.

7. The 3D printing system according to claim 1, characterized in that the rotational motion mechanism includes a stepping motor connected to a series of gears configured for gear reduction between the stepping motor and the machine shaft.

8. The 3D printing system according to claim 1, characterized in that the plurality of arch-shaped 3D articles include a plurality of custom dental arches.

9. A method for manufacturing a plurality of arc-shaped 3D articles using the 3D printing system described in claim 1, A step of rotating and positioning a molding plate having an upper surface of an arch-shaped 3D object so that it is one layer thickness below the upper surface of the photocurable liquid; and The process involves operating the light engine to selectively irradiate a plurality of spatially separated modeling planes, each individually aligned with the upper surface of the arch-shaped 3D object, thereby curing and solidifying slices of photocurable liquid onto the upper surface of the arch-shaped 3D object. Methods that include...

10. The method according to claim 9, characterized in that the slice of the photocurable liquid has a variable thickness proportional to the distance from the rotation axis X.

11. The method according to claim 9, wherein the step of rotating and positioning the molding plate includes a deep immersion motion, wherein the molding plate is rotated to a position where the upper surface of the arch-shaped 3D article is one layer below the upper surface of the photocurable liquid by more than one layer, before rotating to a position where the upper surface of the photocurable liquid is one layer below the upper surface of the photocurable liquid.

12. A method for manufacturing an arc-shaped three-dimensional (3D) article, A step of providing a 3D model of the aforementioned arc-shaped 3D article; A step of slicing the 3D model using a set of slice planes that diffuse from the axial region below the vertices of the arch-shaped 3D model; A step of rotating the upper surface of the molding plate or a partially completed portion of the arch-shaped article around a specific position to provide a layer of photocurable liquid above the upper surface; A step of operating a light engine to selectively cure a layer of photocurable liquid onto the upper surface to form a new upper surface; and A process of repeating the rotational movement step and the operation of the optical engine to complete the fabrication of the arc-shaped 3D object from a series of variable-thickness slices, wherein each slice has a thickness that increases with distance from the specific position. Methods that include...

13. The method according to claim 12, characterized in that the arch-shaped 3D article includes a dental arch.

14. The method according to claim 13, characterized in that the arch-shaped 3D article includes a support structure configured to connect one end of the dental arch to the upper surface of the molding plate.

15. The method according to claim 12, characterized in that the slice plane diffuses from an axis located below the vertex of the arc-shaped 3D model.

16. The method according to claim 15, characterized in that the axis is the rotation axis of the molding plate.

17. The method according to claim 15, characterized in that the step of slicing the 3D model includes the step of forming a stack of slices having a thickness proportional to the radial distance from the axis.

18. The method according to claim 12, characterized in that the slice plane diffuses from the rotation axis of the molding plate.

19. The method according to claim 12, characterized in that the step of rotating the upper surface includes the step of rotating the molding plate around an axis having a fixed rotation axis.

20. A method for manufacturing multiple arc-shaped three-dimensional articles, (1) The process of providing a 3D printing system; (2) A step of operating a rotational movement mechanism to position the individual upper surfaces of the plurality of arc-shaped 3D articles at a position one layer thickness below the upper surface of the photocurable liquid, wherein the thickness of the layer changes linearly along the radius extending from the rotation axis of the machine axis; (3) A step of operating a light engine to selectively irradiate a plurality of molding planes corresponding to each of the plurality of arc-shaped three-dimensional (3D) articles, and a step of curing the trapezoidal slices of the photocurable liquid on the upper surface; and (4) A process to complete the manufacturing of the plurality of arc-shaped three-dimensional articles by repeating steps (2) and (3). Includes, The aforementioned 3D printing system is A molding container configured to contain a photocurable liquid having an upper surface; The following are the individual components included in the build assembly: Axle having a horizontal rotation axis X; A molding plate attached to the shaft, extending radially from the shaft and having an upper surface; and A rotational movement mechanism connected to the aforementioned shaft and configured to rotate and position the shaft around the rotation axis X, and Optical engine located above the aforementioned moldable container Equipped with, A method characterized by the following features.

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