WO2022095704A1

WO2022095704A1 - 3d printing calibration artifact, method for 3d printing calibration and 3d printer

Info

Publication number: WO2022095704A1
Application number: PCT/CN2021/125129
Authority: WO
Inventors: Long Kiu SUEN; Chun Ki YEUNG
Original assignee: Ossfila Technology Limited
Priority date: 2020-11-03
Filing date: 2021-10-21
Publication date: 2022-05-12

Abstract

A 3D printing calibration artifact, which is a polyhedron. The polyhedron comprises: a first face(f1); a second face(f2), which is perpendicular to the first face; a third face(f3), which is perpendicular to the first face and the second face and meets the first face and the second face atone vertex of the polyhedron; and a fourth face(f7) perpendicular to the first face, at least one space diagonal of the polyhedron being in the fourth face, the space diagonal being from disjoint vertices between the second face and the third face; wherein a pocket or an island is on at least one of the first face, the second face, the third face and the fourth face; the shape of the pocket or island is hemisphere, sphere or polyhedron. With the embodiment of the present invention, linearity and curve parameter in multiple dimensions can be calibrated by only one 3D printing collimator.

Description

3D printing calibration artifact, method for 3D printing calibration and 3D printer

TECHNICAL FIELD

The invention relates to the field of 3D printing, in particular to a 3D printing calibration artifact, a method for 3D printing calibration and a 3D printer.

BACKGROUND

3D printing, or additive manufacturing, is a kind of rapid prototyping technology that involves building a model layer by layer. The first account on 3D printed solid model was published by Hideo Kodama in 1981, which laid the foundation for the photopolymer technology. Alain Le Mehaute et al. submitted the first 3D Printing patent for stereolithography (SLA) , a type of Vat Photopolymerization, in 1984.

Various 3D printing methods have spawned since its emergence in the 1980s. The technology of 3D printing can now be classified into multiple processes, including: Vat Photopolymerization, Material Jetting (MJ) , Binder Jetting, Material Extrusion, Powder Bed Fusion, Sheet Lamination (SL) , and Directed Energy Deposition (DED) , etc.

Vat Photopolymerization produces a solid part by exposing a photopolymer resin in liquid form to light of a specific wavelength, thus triggering a chemical reaction that solidifies the resin. Technologies like Stereolithography (SLA) , Direct Light Processing (DLP) , and Continuous DLP (CDLP) fall under this category.

In Material Jetting process, droplets of photosensitive liquids, such as thermoset photopolymers (acrylics) , are dispensed from a printhead and solidified under ultraviolet (UV) light. This method allows for multi-material printing. Nano Particle Jetting (NPJ) and Drop-on-demand (DOD) fall under this category.

Binder Jetting is an additive manufacturing process in which a liquid binding agent is selectively deposited to join powder particles. Layers of material are then bonded to form an object. Binder Jetting is capable of printing a variety of materials including metals, sands and ceramics. Some materials, like sand, require no additional processing. Other materials are typically cured and sintered and sometimes infiltrated with another material, depending on the application.

Material Extrusion is an additive manufacturing technology that involves extruding a filament through a nozzle onto print platform. This technology commonly deals with composite materials and thermoplastics. Fused Deposition Modelling (FDM) , Fused Filament Fabrication (FFF) , Direct Ink Writing (DIW) , also known as Robocasting, fall under this category.

Powder Bed Fusion is an additive manufacturing technology which creates a 3D part one layer at a time using a fine powder as the print medium. This powder is sintered or melted with either a laser or an electron beam as the heat source. Sintering and melting result in different outcomes but both are types of powder bed fusion metal printing. Familiar laser-based systems are known as Selective Laser Melting (SLM) , Selective Laser Sintering (SLS) , Direct Metal Laser Sintering (DMLS) , Electron Beam Melting (EBM) or Direct Metal Laser Melting (DMLM) . These are designations originally created by the machine manufacturers but which have now become industry standard terms.

Sheet Lamination is an additive manufacturing process that creates a solid model by binding sheets of materials, usually metal foil, with adhesive or laminate. Each sheet is cut with a laser or a blade prior to lamination. This process comprises Laminated Object Manufacturing (LOM) and Selective Deposition Lamination (SDL) .

Directed Energy Deposition (DED) is an additive manufacturing process that produces 3D objects layer by layer by directing energy via laser or electron beam at sprayed metal powder or wire feedstock. This technique specifically deals with metals and alloys. There are generally two lower level processes of Direct Energy Deposition: Laser Engineered Net Shaping (LENS) and Electron Beam Freeform Fabrication.

A 3D Printer is the equipment designed to perform 3D printing. Material extrusion printers have a filament feeder; an extrusion head controlled by step motor operated moving axis, and a build platform. Vat polymerization printers include a laser source, resin tank, and a movable build platform. Material jetting printers have a material container, a UV curing light, inkjet print heads, and a build platform. Binder jetting printers have a material container, inkjet print heads, a recoated blade, a powder bed, a build platform, and an overflow bin.

With the aid of the 3D printer, products with complex and detailed appearance, features can be produced, providing convenience and freedom for product designing. For examples, the constraints or limitations of traditional manufacturing such as the undercut and draft angle are eliminated in 3D printing, and the six-sided printing can be provided in one setup.

For the 3D printing technology used in advanced application or production of precision instruments, such as the medical implant and/or mechanical parts, the dimensional accuracy of the 3D printer and the model should be extremely high. So the 3D printers should be calibrated before they are used or mass produced. The current state of calibration of 3D printer is as follows:

The calibration and testing methods of 3D printing technology have not yet been standardized by ISO or OIML. The traditional testing methods are not systematic and general. Most of these are concerning about the performance of the equipment only. The common test objects from 3D Printer open source only comment on the printability of a specific structure subjectively and do not objectively reflect the actual printer performance. The lack of a standard test poses a challenge for the 3D printing industry to compare printer performance quantitatively and qualitatively. Most evaluation methods involve printing multiple models for a single testing of the 3D printer, which is time-consuming and material-consuming.

For the solution of face recognition, it has the following disadvantages:

SUMMARY

Embodiments of the present invention provide a 3D printing calibration artifact, a 3D printer and a method for 3D printing calibration to solve one or more of the above problems.

As an aspect of the embodiments of the present invention, an embodiment of the present invention provides a 3D printing calibration artifact, wherein the 3D printing calibration artifact is a polyhedron, which comprises: a first face; a second face which is perpendicular to the first face; a third face which is perpendicular to the first face and the second face and meets at the first face and the second face at one vertex of the polyhedron; and a fourth face perpendicular to the first face, at least one space diagonal of the polyhedron being in the fourth face, the space diagonal being from disjoint vertices between the second face and the third face; wherein a pocket or an island is on at least one of the first face, the second face, the third face and the fourth face; the shape of the pocket or island is hemisphere, sphere or polyhedron.

As an aspect of the embodiments of the present invention, an embodiment of the present invention provides a method for 3D printing calibration, comprising: performing 3D printing according to a designed 3D model and a designed 3D printing calibration artifact, and obtaining a printed 3D model and a printed 3D printing calibration artifact; wherein the designed 3D printing calibration artifact and the printed 3D printing calibration are the above artifact; determining an error or errors of the designed 3D model and the printed 3D model according to the designed 3D printing calibration artifact and the printed 3D printing calibration artifact; calibrating the 3D printing according to the error or errors.

As an aspect of the embodiments of the present invention, an embodiment of the present invention provides a 3D printer comprising: one or more processors; a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the above method.

The embodiments of the invention provide a 3D printing calibration artifact, a method for 3D printing calibration and a 3D printer, which can calibrate the linear and curve parameters of the 3D printing only based on one 3D printing calibration artifact.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same reference numbers in multiple drawings refer to the same or similar parts or elements, unless otherwise specified. These drawings are not necessarily drawn at scale. It should be understood that these drawings describe only some embodiments under this disclosure and should not be considered as a limitation on the scope of the invention.

Fig. 1 is an isometric view showing a 3D printing calibration artifact according to an embodiment of the present invention.

Fig. 2 is a rear isometric view showing a 3D printing calibration artifact according to an embodiment of the present invention.

Fig. 3 is a flow chart showing a method for 3D printing calibration according to an embodiment of the present invention.

Fig. 4 is a schematic view showing a setting of measurement target 1 to 4 of a 3D printing calibration artifact according to an embodiment of the present invention.

Fig. 5 is a schematic view showing a setting of

measurement target

5, 6, 9 and 10 of a 3D printing calibration artifact according to an embodiment of the present invention.

Fig. 6 is a schematic view showing a setting of

measurement target

7 and 8 of a 3D printing calibration artifact according to an embodiment of the present invention.

Fig. 7A to Fig. 7G are projection views showing on seven different faces according to an embodiment of the present invention.

Fig. 8 is a schematic structural view showing a terminal device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will be further described in detail below with reference to the drawings and embodiments. It is understood that the specific embodiments described herein are illustrative of the invention and are not intended to limit the invention. It should also be noted that, for ease of description, only some, but not all, of the structures related to the present invention are shown in the drawings.

In the description of the present invention, it is to be understood that the terms "center" , "longitudinal" , "transverse" , "length" , "width" , "thickness" , "upper" , "lower" , "front" , "rear" , "left" , "right" , "vertical" , "horizontal" , "top" , "bottom" , "inner" , "out" , "clockwise" , "counterclockwise" , "axial" , "radial" , "circumferential" and the likereferring to the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the indicated devices or elements must have a particular orientation, constructed and operated in a particular orientation. Therefore, this should not to be construed as limiting.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include one or more of the features either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise.

In the present invention, terms such as "installation" , "connected" , "mounted" , and "fixed" are to be used in a broad sense unless specifically defined and defined. For example, it may be a fixed connection, or may be a detachable connection, or may be integrated; it may be a mechanical connection, an electrical connection, or a communication; it may be directly connected or indirectly connected through an intermediate medium; it may be the internal connection of two components or the interaction of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the present invention, the first feature "on" or "under" the second feature may include direct contact of the first and second features, and may also include first and second features, unless otherwise specifically defined and defined. It is not in direct contact but through additional features between them. Moreover, the first feature "above" the second feature includes the first feature directly above and diagonally above the second feature, or merely indicating that the first feature level is higher than the second feature. The first feature "below" the second feature includes the first feature directly below and diagonally below the second feature, or merely the first feature level being less than the second feature.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and arrangements of the specific examples are described below. Of course, they are merely examples and are not intended to limit the invention. In addition, the present invention may be repeated with reference to the numerals and/or reference numerals in the various examples, which are for the purpose of simplicity and clarity, and do not indicate the relationship between the various embodiments and/or arrangements discussed.

Embodiments of the present invention provide a 3D printing calibration artifact that can measure and calibrate linear and curve parameters of a plurality of dimensions of an object, and can evaluate materials used for printing and performance of a printing device to print the object. The 3D printing calibration artifact is a polyhedron. In some embodiments, it may be cut based on a cube or a cuboid and provided with pockets or islands in faces. The shape of the pocket or island is a polyhedron, hemisphere or sphere that is convenient for measurement. The shape of the polyhedron may include a tetrahedron, a cuboid, a cube, a cylinder, a cone, or the like.

In some embodiments, in order to facilitate the measurement of the size of the calibration artifact, one vertex of the cube or the cuboid may be used as the origin of the three-dimensional reference coordinate system, and the three edges of the cube or the cuboid perpendicular to each other and meet at the vertex are respectively used as the three axes of the three-dimensional reference coordinate system. The three faces of the cube or cuboid perpendicular to each other and meeting at the vertex serve as three planes of the 3D printing calibration artifact, and the other faces may be cut as needed. The fourth face is perpendicular to at least one of the three faces, and the diagonal plane of the vertices that the other two faces do not meet at is in the fourth face, which makes it easy to measure and calibrate the three-dimensional parameters of 3D printing.

The 3D printing calibration artifact provided by the embodiments of the present invention will be described in detail below.

Referring to Fig. 1 and Fig. 2, Fig. 1 shows an isometric view of a 3D printing calibration artifact provided according to an embodiment of the present invention. Fig. 2 is a rear isometric view showing a 3D printing calibration artifact provided according to an embodiment of the present invention. The 3D printing calibration artifact is a polyhedron, and the face of the polyhedron may include a plane and a curved surface. The polyhedron may include three faces that are perpendicular to each other and intersect one vertex, that is, a first face f (1) , a second face f (2) , and a third face f (3) . This vertex is the origin of the reference coordinate system X-Y-Z. The intersections of the three planes are on the three coordinate axes of the coordinate system, namely the X-axis, the Y-axis, and the Z-axis. The first face f (1) may be the bottom face which is the X-Y plane of the artifact. The second face f (2) may be the front face which is the X-Z plane of the artifact. The third face f (3) may be the left hand side face which is the Y-Z plane of the 3D printing calibration artifact. The polyhedron may further include a fourth face f (7) perpendicular to the first face f (1) , and the diagonal of the plane where the vertex of the second plane f (2) and the third plane f (3) do not meet at is in the fourth plane f (7) .

The first face f (1) , the second face f (2) , the third face f (3) , and the fourth face f (7) may each be a rectangular plane, which may be a square as shown in Fig. 1 and Fig. 2. The lengths of the edges where the first face f (1) intersects the second face f (2) are the same, the lengths of the edges where the second face f (2) intersects the third face f (3) are the same, and the lengths of the edges where the third face f (3) intersects the first face f (1) are the same.

Pockets or islands are provided on at least one of the first face f (1) , the second face f (2) , and the third face f (3) . These pockets or islands are spheres or polyhedrons that can be easily measured, such as a cuboid, a cube, a cylinder, a hemisphere, a sphere, and the like.

Illustratively, as shown in Fig. 1 and Fig. 2, the 3D printing calibration artifact provided by the embodiment of the present invention may comprises: three square faces that are perpendicular to each other and meet at one point vertex, a fourth face f (7) of a rectangle perpendicular to one of the square faces and being at an angle of 45 degrees to the other two faces, three pockets provided on these three square faces, three blind holes on different faces, a cylindrical island on one of the faces, and a sphere.

Illustratively, as described in Fig. 2, the 3D printing calibration artifact can also comprise a fifth face f (6) , which can be the top face of the 3D printing calibration artifact. The fifth face f (6) is offset upward relative to the first face f (1) , and the height of the offset is the height of the second face f (2) or the third face f (3) , which is the length of the intersection between the third face f (3) and the second face f (2) . The fifth face f (6) may be an irregular plane. The sides of the fifth face f (6) are perpendicularly connected to the second face f (2) , the third face f (3) and the fourth face f (7) respectively.

In some embodiments, in order for the 3D printing calibration artifact to stand firmly above the ground plane, at least one of the first face f (1) and the fifth face f (6) is not provided with an island. Exemplarily, the first face f (1) is not provided with an island, and the area of the first face f (1) is at least not smaller than the area of the fifth face f (6) , and the 3D printing calibration artifact can be stably supported..

In some embodiments, a blind hole is provided in at least one of the first face f (1) , the second face f (2) and the third face f (3) . As shown in Fig. 1, the second face f (2) and the third face f (3) are respectively provided with one blind hole. The diameter of the two blind holes can be the same.

In some embodiments, a blind hole may be provided in the fifth face f (6) . For example, if the first face f (1) is provided with a blind hole, the fifth face f (6) may not have a blind hole or a cylindrical island. If no blind holes are provided in the first face f (1) , the fifth face f (6) may be provided with blind holes or cylindrical islands.

In some embodiments, the second face f (2) , the third face f (3) and the fifth face f (6) are each provided with a blind hole or a cylindrical island. For example, as shown in Fig. 1 and Fig. 2, the second face f (2) , the third face f (3) and the fifth face f (6) are each provided with a blind hole, which can be used to measure a two-dimensional curve error.

The first face f (1) , the second face f (2) and the third face f (3) may be squares having the same outer dimensions. At least one plane of the first face f (1) , the second face f (2) and the third face f (3) is provided with a rectangular pocket or island, which can be used for two-dimensional linearity error.

Illustratively, rectangular pockets are provided in all three planes of the first face f (1) , the second face f (2) and the third face f (3) . The size of each rectangular pocket may be the same or different. As shown in Fig. 1, each rectangular pocket may have a central axis that coincides with or is parallel to the face diagonal.

Illustratively, the first face f (1) is provided with a rectangular pocket on the diagonal, and the second face f (2) and the third face f (3) are provided with rectangular pockets on the diagonal and blind holes aside.

In some embodiments, a rectangular pocket or island is provided on the diagonal of the fourth face f (7) , which can be used to measure three-dimensional linearity errors. The central axis of the rectangular pocket or island may be parallel or coincident with the diagonal of the fourth face f (7) .

In some embodiments, in order to improve the stability of the 3D printing calibration artifact placed on the ground, the 3D printing calibration artifact may further include a sixth face f (8) located above the first face f (1) , and the sixth face f (8) intersects perpendicularly to the fourth face f (7) . As shown in Fig. 2, the sixth face f (8) is a triangular plane offset upward relative to the first face f (1) , the oblique side of the triangle intersects the sixth face f (8) , and the offset is less than the height of the fifth face f (6) offset relative to the first face f (1) .

In some embodiments, some polyhedrons, such as cylinders, spheres, etc., may be placed on the sixth face f (8) .

Illustratively, as shown in Fig. 2, a cylinder (cylindrical island) c (1) is placed on the sixth face f (8) , and a sphere s (1) is placed on the cylinder c (1) . In some embodiments, a support cylinder may be placed between the cylinder c (1) and the sphere s (1) to support the sphere on the bottom plane of the cylinder c (1) . In this example, the cylinder c (1) or the sphere s (1) can be utilized to measure the three-dimensional curve size or error.

In some embodiments, the fourth face f (7) may not intersect the first face f (1) , the second face f (2) , and the third face f (3) . As shown in Fig. 2, the 3D printing calibration artifact may further include a flipped L-shaped seventh face f (4) and a L-shaped eighth face f (5) . The two outer edges of the seventh face f (4) intersect perpendicularly with the first face f (1) and the third face f (3) , respectively, and the inner edge of the seventh face f (4) parallel to the first face f (1) intersects the sixth face f (8) . The two outer sides of the eighth face f (5) intersect perpendicularly with the first face f (1) and the second face f (2) , respectively, and the inner edge of the eighth face f (5) parallel to the first face f (1) intersects the sixth face f (8) .

In some embodiments, a pocket or island may be provided on the seventh face f (4) and the sixth face f (8) . The shape of the pocket or island may be a polyhedron or a sphere.

As an example of embodiments of the present invention, a method for 3D calibrating with the above 3D printing calibration artifact provided will be described below. As shown in Fig. 3, the calibration method comprises:

S100. Performing 3D printing according to a designed 3D model and a designed 3D printing calibration artifact, and obtaining a printed 3D model and a printed 3D printing calibration artifact.

It should be noted that the designed 3D model and the designed 3D printing calibration artifact are the targets referenced by this 3D printing. The printed 3D model and the printed 3D printing calibration artifact are the result of this 3D printing. This 3D printing can print a plurality of objects which can be called the printed 3D model and a plurality of artifacts which can be called the printed 3D printing calibration artifact.

Printing the object and the calibration artifact at the same time or next print immediately. It help to compare the dimension consistency of the printer or the material in different print, not limited to the second, but also the third, fourth or more printing for the statistical requirement.

S200. Determining an error or errors between the designed 3D model and the printed 3D model according to the designed 3D printing calibration artifact and the printed 3D printing calibration artifact.

For any measurement target, the size of the measurement target is measured in the designed 3D printing calibration artifact and the printed 3D printing calibration artifact respectively, and the difference between the two is calculated, and the difference is the error of the measurement target reflecting the printing precision of a 3D printer with a specific material. Further, determining a repeatability error or repeatability errors between any two printed 3D models according to any two printed 3D printing calibration artifacts. These repeatability errors reflect the repeatability of a 3D printer with a specific material printing these 3D models.

In some embodiments, the error determined in the above step S200 may include a one-dimensional linear error. The one-dimensional linear error can include a single axial linearity error on three axes. As shown in Fig. 4, regarding the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the first measurement target is set at a position close to the first vertex v (1) on the third face f (3) , and the second measurement target is set at a position close to the second vertex v (2) on the eighth face f (5) . The distance between the first measurement target and the second measurement target is measured by a measurement tool such as a vernier caliper or a micrometer. The measurement distance L (1a) is measured between the first measurement target and the second measurement target of the designed 3D printing calibration artifact. The measurement distance L (1b) is measured between the first measurement target and the second measurement target of the printed 3D printing calibration artifact. The value obtained by subtracting L (1b) from L (1a) is a one-dimensional linear error on the X-axis at bottom layer. In some embodiments, L (1a) can be measured multiple times and be averaged, L (1b) is measured multiple times and be averaged, and the one-dimensional linear error is calculated by subtracting the averaged L (1b) from the averaged L (1a) .

A third measurement target is disposed at a position close to the fifth vertex v (5) on the third face f (3) , and a fourth measurement target is set at a position near the sixth vertex v (6) on the eighth face f (5) . The measurement distance L (1.1a) is measured between the third measurement target and the fourth measurement target of the designed 3D printing calibration artifact. The measurement distance L (1.1b) is measured between the third measurement target and the fourth measurement target of the printed 3D printing calibration artifact. The value obtained by subtracting L (1.1b) from L (1.1a) is a one-dimensional linear error on the X-axis at top layer.

L (1.1b) is measured multiple times and averaged, and L (1b) is measured multiple times and averaged. Then, the value obtained by subtracting the averaged L (1.1b) from the averaged L (1b) can be used to evaluate the error between the top layer and the bottom layer of the 3D printed product, which can be called the deformation error.

As shown in Fig. 5, a sixth measurement target is near the fourth vertex v (4) on the seventh face f (4) , and a fifth measurement is near the first vertex v (1) on the second face f (2) . The distance between the sixth measurement target and the fifth measurement target is measured by a measuring tool such as a vernier caliper or a micrometer. The measurement distance L (2a) is measured between the fifth measurement target and the sixth measurement target of the designed 3D printing calibration artifact. The measurement distance L (2b) is measured between the fifth measurement target and the sixth measurement target of the printed 3D printing calibration artifact. The value obtained by subtracting L (2b) from L (2a) is the one-dimensional linear error on the Y-axis.

L (2a) is measured multiple times and averaged, and L (2b) is measured multiple times and averaged. Then the one-dimensional linear error on the Y-axis can be calculated by subtracting the averaged L (2b) from the averaged L (2a) .

As shown in Fig. 6, an eighth measurement target is disposed on the fifth face f (6) near the fifth vertex v (5) , and a seventh measurement target is disposed on the first face f (1) near the first vertex v (1) . The distance between the seventh measurement target and the eighth measurement target is measured by a measuring tool such as a vernier caliper or a micrometer. The measurement distance L (3a) is measured between the seventh measurement target and the eighth measurement target of the designed 3D printing calibration artifact. The measurement distance L (3b) is measured between the seventh measurement target and the eighth measurement target of the printed 3D printing calibration artifact. The value obtained by subtracting L (3b) from L (3a) is the one-dimensional linear error on the Z-axis.

L (3a) is measured multiple times and averaged, and L (3b) is measured multiple times and averaged. Then the one-dimensional linear error on the Z-axis can be calculated by subtracting the averaged L (3b) from the averaged L (3a) .

In some embodiments, the one-dimensional linearity error may be selected from the maximum of one-dimensional linear error values on the X-axis, the Y-axis and the Z-axis.

Since a rectangular pocket or a rectangular island can be provided on the faces of the 3D printing calibration artifact, the two-dimensional linearity error can also be measured by the 3D printing calibration artifact.

As shown in Fig. 1, the first face f (1) , the second face f (2) and the third face f (3) of the 3D printing calibration artifact each includes a rectangular pocket, and the central axis of the rectangular pocket coincides with the face diagonal. The two-dimensional linearity error may be selected from the largest edge length errors of the rectangular pockets of the first face f (1) , the second face f (2) and the third face f (3) .

As shown in Fig. 7A, the measurement process of the edge length error of the rectangular pocket on the first face f (1) may be as follows: for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, using tool, such as a vernier caliper, a micrometer, etc. to measure the length L (4) of the rectangular pocket on the first face f (1) . Subtracting L (4) of the printed 3D printing calibration artifact from L (4) of the designed 3D printing calibration artifact to obtain a two-dimensional linear error of the first face f (1) , which is two-dimensional linear error on the X-Y plane. The central axis of the rectangular pocket is located on the diagonal between the first vertex v (1) and the third vertex v (3) .

As shown in Fig. 7B, the measurement process of the edge length error of the rectangular pocket on the second face f (2) may be as follows: for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, using tool such as a vernier caliper, a micrometer, etc. to measure the length L (5) of the rectangular pocket on the second face f (2) . Subtracting L (5) of the printed 3D printing calibration artifact from L (5) of the designed 3D printing calibration artifact to obtain a two-dimensional linear error of the second face f (2) , which is two-dimensional linear error on the X-Z plane. The central axis of the rectangular pocket is located on the diagonal between the first vertex v (1) and the sixth vertex v (6) .

As shown in Fig. 7C, the measurement process of the edge length error of the rectangular pocket of the third face f (3) may be as follows: for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, using tool such as a vernier caliper, a micrometer, etc. to measure the length L (6) of the rectangular pocket on the third face f (3) . Subtracting L (6) of the printed 3D printing calibration artifact from L (6) of the designed 3D printing calibration artifact to obtain a two-dimensional linear error of the third face f (3) , which is two-dimensional linear error on the Y-Z plane. The central axis of the rectangular pocket is located on the diagonal between the first vertex v (1) and the eighth vertex v (8) .

In some embodiments, the two-dimensional linear error can be measured multiple times and averaged.

The fourth face f (7) of the 3D printing calibration artifact may comprise a rectangular island or a rectangular pocket. As shown in Fig. 2, the fourth face f (7) includes a rectangular island, and the error described above may include a three-dimensional linear error, which is an edge length error of the rectangular island on the fourth face f (7) .

As shown in Fig. 7G, the measurement process of the edge length error of the rectangular island of the fourth face f (7) may be as follows: for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, using tool such as a vernier caliper, a micrometer, etc. to measure the length L (7) of the rectangular pocket on the fourth face f (7) . Subtracting L (7) of the printed 3D printing calibration artifact from L (7) of the designed 3D printing calibration artifact, a three-dimensional linear error of the fourth face f (7) , that is, a three-dimensional linear error on the X-Y-Z plane is obtained. The diagonal of the second vertex v (2) and the eighth vertex v (8) falls on the fourth face f (7) .

In some embodiments, the three-dimensional linear error can be measured multiple times and averaged.

As shown in Fig. 1 and Fig. 2, the face of the 3D printing calibration artifact may include a blind hole, and the error may include an hole diameter error and a two-dimensional curve error; the hole diameter error is a hole diameter error of the blind hole, and the two-dimensional curve error is the measurement range of the diameter of a blind hole.

As shown in Fig. 1 &2, the fifth face f (6) , the second face f (2) and the third face f (3) of the 3D printing calibration artifact respectively include blind holes, respectively being the first blind hole h (1) and the second blind hole h (2) and third blind hole h (3) . Wherein, the hole diameter error may be selected from the largest one of the hole diameter errors of the blind holes of the fifth face f (6) , the second face f (2) , and the third face f (3) . The two-dimensional curve error may be selected from the widest range of the measurement ranges of the diameters of the blind holes of the fifth face f (6) , the second face f (2) and the third face f (3) .

As shown in Fig. 7D, for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the diameter D (1) of the first blind hole on the fifth face f (6) is measured respectively. The diameter D (1) of the printed 3D printing calibration artifact is subtracted from the diameter D (1) of the designed 3D printing calibration artifact to obtain an hole diameter error of the fifth face f (6) .

Since the printed 3D printing calibration artifact is the result of the 3D printing, a plurality of the printed 3D printing calibration artifacts can be printed. In some embodiments, for a plurality of the printed 3D printing calibration artifacts, the diameter D (1) of the first blind hole on the fifth face f (6) is respectively measured to determine the measurement range of the diameter of the blind hole on the fifth face f (6) .

As shown in Fig. 7B, for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the diameter D (2) of the second blind hole on the second face f (2) is measured respectively. The diameter D (2) of the printed 3D printing calibration artifact is subtracted from the diameter D (2) of the designed 3D printing calibration artifact to obtain an hole diameter error of the second face f (2) .

For a plurality of the printed 3D printing calibration artifacts, the diameter D (2) of the second blind hole on the first face f (1) is respectively measured to determine the measurement range of the diameter of the blind hole on the first face f (1) .

As shown in Fig. 7C, for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the diameter D (3) of the third blind hole on the third face f (3) is measured respectively. The diameter D (3) of the printed 3D printing calibration artifact is subtracted from the diameter D (3) of the designed 3D printing calibration artifact to obtain an hole diameter error of the third face f (3) .

For a plurality of the printed 3D printing calibration artifacts, the diameter D (3) of the second blind hole on the third face f (3) is respectively measured to determine the measurement range of the diameter of the blind hole on the third face f (3) .

The 3D printing calibration artifact may also include a cylinder. As shown in Fig. 2, the sixth face f (8) is provided with a cylinder, and the embodiment of the present invention can measure the cylinder diameter error and the two-dimensional curve error. Among them, the two-dimensional curve error is the measurement range of the cross-sectional diameter of the cylinder.

As shown in Fig. 7D, for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the diameter D (4) of the cylinder on the sixth face f (8) is measured respectively. The diameter D (4) of the cylinder of the printed 3D printing calibration artifact is subtracted from the diameter D (4) of the cylinder of the 3D printing calibration artifact to obtain a cylinder diameter error.

For a plurality of the printed 3D printing calibration artifacts, the diameter D (4) of the cylinder is measured respectively, and the measurement range of the diameter D (4) is taken as a two-dimensional curve error.

The sphere may also be included on the face of the 3D printing calibration artifact. As shown in Fig. 2, a sphere is disposed on the cylinder of the sixth face f (8) , and the embodiment of the present invention can also measure the sphere diameter error and the three-dimensional curve error. Among them, the three-dimensional curve error is the measurement range of the diameter of the sphere.

As shown in Fig. 7E, for the designed 3D printing calibration artifact and the printed 3D printing calibration artifact, the diameter D (5) of the sphere is measured respectively. The diameter D (5) of the sphere of the printed 3D printing calibration artifact is subtracted from the diameter D (5) of the sphere of the designed 3D printing calibration artifact to obtain a cylinder diameter error.

For a plurality of the printed 3D printing calibration artifacts, the diameter D (5) of the sphere is measured respectively, and the measurement range of the diameter D (5) is taken as a three-dimensional curve error.

S300. Calibrating the 3D printing according to the error or errors.

Based on the determined error or errors, it can then immediately be corrected and fine-tuned the printing design to print out the calibrated object and artifact (further verification on dimensional accuracy can be performed) , or confirmed the printability of the current printed object and artifact (whether they are printed within the acceptable range or not) . Afterward, it can repeatedly be printed out rounds of object and artifact to see the consistency/repeatability (preciseness) of the printing. At the end, we can build up a database for evaluating the 3D printer’s performance under specific material and benchmark the printer.

The calibration artifact can also be used in calibration of other object that is produced by different prototyping method, such as subtractive manufacturing.

The calibration method provided by the above embodiments can be applied to include, but is not limited to, the following:

Testing linear and curve accuracy in 1D, 2D and 3D for products printed on 3D printers;

Fine-tuning the 3D printer during final assembly;

Precisely setting the 3D printer before each part and production lot;

Testing the performance of 3D printers, testing the performance of 3D print slicing programs and testing the performance of 3D modeling software;

Testing the accuracy of 3D printed models, especially advanced applications or sophisticated instruments such as medical implants, surgical instruments, medical equipment, construction parts, mechanical parts or accessories;

Calibrating the process of making a subtractive manufacture;

Evaluating the printability of 3D printed materials.

Developing compensation systems for linear and curved surfaces.

Bench marking or acceptance testing 3D printers. For example: commercial contracts, sales and OEM.

Evaluating the printer resolution.

The following describes the specific process of error measurement by using the designed 3D printing calibration artifact as a standard part:

Design of the artifact:

The artifact is a cubic block of 25.00 mm × 25.00 mm × 25.00 mm in size.

Details of the artifact are shown in Fig. 7A to Fig. 7G in third angle projection.

The front low left vertex v (1) is taken as the origin (0, 0, 0) of the coordinate system of the artifact.

The information of eight vertexes of the cube is shown in table 1.

Table1: Coordinate of vertexes

Vertex	coordinate
v (1)	(0, 0, 0)
v (2)	(25, 0, 0)
v (3)	(25, 25, 0)
v (4)	(0, 25, 0)
v (5)	(0, 0, 25)
v (6)	(25, 0, 25)
v (7)	(25, 25, 25)
v (8)	(0, 25, 25)

Face f (1) is the bottom face which is the X-Y plane of the artifact.

Face f (2) is the front face which is the X-Z plane of the artifact.

Face f (3) is the left hand side face which is the Y-Z plane of the artifact.

Face f (1) , f (2) and f (3) are mutually perpendicular meet at vertex v (1) .

The important features of the artifact are: a cubic block consisting of three rectangular pockets on face diagonals, a rectangular island on space diagonal, three blind holes, a cylinder and a sphere.

The feature about the three rectangular pockets along face diagonals is as follows:

Three rectangular pockets with cross section 3 mm width × 3 mm depth are on the face diagonals, see Fig. 7A to Fig. 7C and Fig. 2.

The first face diagonal pocket fdp (1) is on face diagonal v (1) v (3) of face f (1) which is the X-Y plane of the artifact. The length of this pocket is L (4) with nominal length of 20.00 mm.

The second face diagonal pocket fdp (2) is on face diagonal v (1) v (6) of face f (2) which is the X-Z plane of the artifact. The length of this pocket is L (5) with nominal length of 20.00 mm.

The third face diagonal pocket fdp (3) is on face diagonal v (1) v (8) of face f (3) which is the Y-Z plane of the artifact. The length of this pocket is L (6) with nominal length of 20.00 mm.

The information of these three face diagonals is shown in table 2.

Table 2: Face diagonal pockets

The feature of the Rectangular Island along space diagonal is as follows:

A rectangular island sdri (1) is on face f (7) . The axis of the island is along space diagonal between v (2) and v (8) .

Face f (7) is a plane through the face diagonal of XY plane between v (6) and v (8) . Detail of f (7) is shown in the plan and elevation of the artifact in Fig. 7G.

The island is 3 mm width × 3 mm height and length L (7) with nominal length of 20.00 mm.

The information of the space diagonal rectangular island diagonals is shown in table 3.

Table 3: Space diagonal rectangular island

The feature of the three blind holes is as follows:

A blind hole h (1) is on the top face f (6) of the artifact. The diameter of the blind hole h (1) is D (1) with nominal diameter of 10 mm and depth of 3 mm.

A blind hole h (2) is on the front face f (2) of the artifact. The diameter of the blind hole h (2) is D (2) with nominal diameter of 10 mm and depth of 3 mm.

A blind hole h (3) is on the left hand face f (3) of the artifact. The diameter of the blind hole is D (3) with nominal diameter of 10 mm and depth of 3 mm.

The information of these holes is shown in table 4.

Table 4: Blind holes

The feature of cylinder is as follows:

A cylinder c (1) is above the face f (8) of the artifact. The face f (8) is 5 mm offset above the bottom face f (1) . The diameter of the cylinder c (1) is D (4) with nominal diameter of 10.00 mm.

The feature of the sphere is as follows:

A sphere s (1) is above the cylinder c (1) . The diameter of the sphere s (1) is D (5) with nominal diameter of 10.00 mm.

The following is to describe the calibration of the 3D printing calibration artifact:

The calibration artifact is carried out by length measuring equipment. Nineteen measurands are calibrated according to the following. The 3D printer printing set-up paraments, material, date of printing and working environments shall be fully recorded.

Calibration of E (1) , which is the error in length of the cube. Li (1) is the measured length of the cube between

measurement target

1 and 2 at vertex v (1) and v (2) respectively. The two measurement targets are shown in Fig. 4. The size of the measurement target is 7 mm × 7 mm which can accommodate the anvils of a standard micrometer. Measuring Li (1) four times by a micrometer, where i = 1, 2, 3 or 4. L (1) is the mean of these four measurement. E (1) = L (1) –25.00.

Calibration of E (ΔL (1) ) , which is the difference of length of the cube at bottom and top. Li (1.1) is the measured length of the cube between

measurement target

3 and 4 at vertex v (5) and v (6) respectively. The two measurement targets are shown in Fig. 4. The size of the measurement target is 7 mm× 7 mm which can accommodate the anvils of a standard micrometer. Measuring Li (1.1) four times by a micrometer, where i = 1, 2, 3 or 4. L (1.1) is the mean of these four measurement. E (ΔL (1) ) = L (1.1) –L (1) .

Calibration of E (2) , which is the error in width of the cube. L (2) is the measured width of the cube between

measurement target

5 and 6 at vertex v (1) and v (4) respectively. The two measurement targets are shown in Fig. 5. The size of the measurement target is 7 mm× 7 mm which can accommodate the anvils of a standard micrometer. Measuring Li (2) four times by a micrometer, where i = 1, 2, 3 or 4. L (2) is the mean of these four measurement. E (2) = L (2) –25.00.

Calibration of E (ΔL (2) ) , which is the difference of width of the cube at bottom and top. Li (2.1) is the measured length of the cube between measurement target 9 and 10 at vertex v (5) and v (8) respectively. The two measurement targets are shown in Fig. 5. The size of the measurement target is 7 mm× 7 mm which can accommodate the anvils of a standard micrometer. Measuring Li (2.1) four times by a micrometer, where i = 1, 2, 3 or 4. L (2.1) is the mean of these four measurement. E (ΔL (2) ) = L (2.1) –L (2) .

Calibration of E (3) , which is the error in height of the cube. Li (3) is the measured height of the cube between the

measurement target

7 and 8 at vertex v (1) and v (5) respectively. The two measurement targets are shown in Fig. 6. The size of the measurement target is 7 mm× 7 mm which can accommodate the anvils of a standard micrometer. Measuring Li (3) four times by a micrometer, where i = 1, 2, 3 or 4. L (3) is the mean of these four measurement. E (3) = L (3) –25.00.

Calibration of E (4) , which is the error of length in X-Y face diagonal. Li (4) is the measured length of fdp (1) . Measuring Li (4) four times by a digital/Vernier caliper, where i = 1, 2, 3 or 4. L (4) is the mean of these four measurement. E (4) = L (4) –20.00.

Calibration of E (5) , which is the error of length in X-Z face diagonal. Li (5) is the measured length of fdp (2) . Measuring Li (5) four times by a digital/vernier caliper, where i =1, 2, 3 or 4. L (5) is the mean of these four measurement. E (5) = L (5) –20.00.

Calibration of E (6) , which is the error of length in Y-Z face diagonal. Li (6) is the measured length of fdp (3) . Measuring Li (6) four times by a digital/vernier caliper, where i =1, 2, 3 or 4. L (6) is the mean of these four measurement. E (6) = L (6) –20.00.

Calibration of E (7) , which is the error of length in X-Y-Z space diagonal. Li (7) is the measured length of rectangular island along space diagonal. Measuring Li (7) four times by a digital/vernier caliper, where i = 1, 2, 3 or 4. L (7) is the mean of these four measurement. E (7) = L (7) –20.00.

Calibration of E (8) , which is the error of diameter D (1) of blind hole h (1) at top face f (6) . Di (1) is the measured diameter of blind hole h (1) . Measuring Di (1) four times by a digital/vernier caliper, where i = 1, 2, 3 or 4. D (1) is the mean of these four measurement. E (8) = D (1) –10.00.

Calibration of E (8.1) , which is the cylindricity of blind hole at top face f (6) . E (8.1) is the range of Di (1) measured diameter of blind hole h (1) .

Calibration of E (9) , which is the error of diameter D (2) of blind hole h (2) at front face f (2) . Di (2) is the measured diameter of blind hole h (2) . Measuring Di (2) four times by a digital/vernier caliper, where i = 1, 2, 3 or 4. D (2) is the mean of these four measurement. E (9) = D (2) –10.00.

Calibration of E (9.1) , which is the cylindricity of blind hole at front face f (2) . E (9.1) is the range of Di (2) measured diameter of blind hole h (2) .

Calibration of E (10) , which is the error of diameter D (3) of blind hole h (3) at right hand face f (3) . Di (3) = measured diameter of blind hole h (3) . Measuring Di (3) four times by a digital/vernier caliper, where i = 1, 2, 3 or 4. D (3) is the mean of these four measurement. E (10) = D (3) –10.00.

Calibration of E (10.1) , which is the cylindricity of blind hole h (3) at right hand face f (3) . E (10.1) is the range of Di (3) measured diameter of blind hole h (3) .

Calibration of E (11) , which is the error of diameter of cylinder c (1) above the face f (8) . Di (4) is the measured diameter of cylinder c (1) above face f (8) . Measuring Di (4) four times by a digital/vernier caliper, where i = 1, 2, 3 or 4. D (4) is the mean of these four measurement. E (11) = D (4) –10.00.

Calibration of E (11.1) , which is cylindricity of cylinder c (1) above the face f (8) . E (11.1) is the range of Di (4) measured diameter of cylinder c (1) above face f (8) .

Calibration of E (12) , which is the error of diameter of the sphere s (1) above cylinder c (1) . Di (5) is the measured diameter of sphere s (1) . Measuring Di (5) seven times by a digital/vernier caliper, where i = 1, 2, 3 or 7. D (5) is the mean of these seven measurement. E (12) = D (5) –10.00.

Calibration of E (12.1) , which is the sphericity of sphere s (1) above cylinder c (1) . E (12.1) is the range of Di (5) measured diameter of sphere s (1) above cylinder c (1) .

The calibration results of 3D printer are as follows.

Based on the calibration results of the nineteen measurands of the 3D printer artifact, the performance of the 3D printer under test can be drawn in table 5, as follows.

Table 5: Calibration results of 3D printer

Based on the calibration results, a 3D printer can be benchmarked according to the error listed in table 6, as follows.

Table 6: Bench marking of 3D printer

Based on these errors in Table 6, the performance of a 3D printer can be measured and evaluated.

The calibration artifact can calibrate linear accuracy of a 3D printer in junction of a specified material on: i) single axis in three principal axis (X, Y and Z axis) , ii) two axis in three principal planes (X-Y, Y-Z and X-Z planes) and iii) three axis (XYZ plane) through seven measurands in seven defined directions. The linear accuracy can be referred to the linear errors of No. 1 to No. 3 in Table 6.

The calibration artifact may further calibrate the dimension difference between bottom layer and top layer of the printed product which indicates the thermo and gravitational deformation of material between the top plate (near to the nozzle or energy source) and the bottom plate (near to the build plate or material reservoir) . This calibration can be referred to the dimension error of No. 10 in Table 6.

The calibration may further calibrate curve surfaces accuracy of a 3D printer in junction of a specified material on 2D curve in three principal planes (X-Y, Y-Z and X-Z planes) . This curve surfaces accuracy can be referred to the error of No. 5 in Table 6.

The calibration artifact may further calibrate curve surfaces accuracy of a 3D printer in junction of a specified material on 3D curve. This curve surfaces accuracy can be referred to the error of No. 9 in Table 6.

The calibration artifact may calibrate linear accuracy of a product of a specified material printed by 3D printer on: i) single axis in three principal axis (X, Y and Z axis) , ii) two axis in three principal planes (X-Y, Y-Z and X-Z planes) and iii) three axis (X-Y-Z planes) through seven measurands in seven defined directions. This linear accuracy can be referred to the linear errors of No. 1 to No. 3 in Table 6.

The calibration artifact may calibrate accuracy of a product printed by a 3D printer on 2D curve in three principal planes (X-Y, Y-Z and X-Z planes) , which can be referred to No.5 in Table 6, and on 3D curve, which can be referred to No. 9 in Table 6.

The calibration artifact comprises six measurement targets to measure three axis accuracies in X, Y and Z axis to provide repeatable results and without any influence of geometrical imperfection of the artifact. The measurement target is 7 mm × 7 mm which accommodate the anvil of a standard micrometer. The diameter of the anvil is 0.25 inch (6.35 mm) .

The calibration artifact comprises two measurement targets to measure material shrinkage to provide repeatable results without any influence of geometrical imperfection of the artifact. The measurement target is 7 mm × 7 mm which accommodate the anvil of a standard micrometer. The diameter of the anvil is 0.25 inch (6.35 mm) .

The calibration artifact is configured to test printer resolution. In a 3D Printer, the resolution is defined by the nozzle diameter and the layer height (distance between each level along the z-axis) .

The geometry accuracy along z-axis and the dimension error between bottom layer and top layer reflect the printing quality. In addition, the resolution of printed model or object should follow the setting of the slicing software and the computer model.

The calibration artifact is configured to test material printability. In a 3D Printer, the printability describes the ability of a material to be printed in a desired model by a specific 3D Printing method or setting. Once the calibration artifact printed completely with errors within the acceptable range, the printability of the material in the specific 3D Printing method or setting are proved.

The calibration artifact is configured to test the model accuracy.

The calibration artifact comprises capability of development of machine compensation system in linear and curve aspect.

The calibration artifact comprises capability of bench marking /acceptance test for 3D printer for commercial contract, sales and OEM.

The calibration artifact is configured for machine builder to fine toning /adjustment of the machine at final assembly.

The calibration artifact is configured for fine setting of the machine before each part and production batch.

The calibration artifact is configured to test the performance of 3D printer.

The calibration artifact is configured to test the performance and function of 3D printing slicing program and the 3D modeling software.

The calibration artifact is configured to test the model accuracy, especially for the 3D printing model used in advanced application or precision instrument, such as medical implant, surgical instruments, medical device, construction parts, or mechanical parts and accessories, etc.

The calibration artifact is configured to be the foundation of testing standard of 3D printing quality and assistant of 3D model design.

The calibration procedure is configured to calibrate the 3D printer using the artifact and to benchmark a 3D printer.

The calibration procedure is configured to calibrate the subtractive manufacturing process using the artifact and to benchmark a subtractive manufacturing process.

As an example of the embodiment of the present application, the embodiment of the present application provides a design as follows: a device for 3D printing calibration includes a processor and a memory, the memory being configured to store a program corresponding to the above-mentioned 3D printing calibration method executed by the 3D printing calibration device, and the processor being con igured to execute a program stored in the memory. The device for 3D printing calibration further includes a communication interface for communicating with the other device or communication network for the 3D printed alignment device.

The device also includes:

a communication interface 23, which is configured for communication between the processor 22 and an external device;

a memory 21, which may include a high speed RAM memory and may also include a non-volatile memory such as at least one disk memory.

If the memory 21, the processor 22, and the communication interface 23 are independently implemented, the memory 21, the processor 22, and the communication interface 23 can be connected to each other through a bus and communicate with each other. The bus may be an Industrial Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Component (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Fig. 8, but it does not mean that there is only one bus or one type of bus.

Optionally, in a specific implementation, if the memory 21, the processor 22 and the communication interface 23 are integrated on one chip, the memory 21, the processor 22, and the communication interface 23 can communicate with each other through the internal interface.

In the description of the present specification, the description with reference to the terms "one embodiment" , "some embodiments" , "example" , "specific example" , or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the application. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, various embodiments or examples described in the specification, as well as features of various embodiments or examples, may be combined and combined. In addition, without contradicting each other, those skilled in the art may combine the different embodiments or examples described in this specification with the characteristics of the different embodiments or examples.

Any process or method description in the flowcharts or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a particular logical function or process. And the scope of the preferred embodiments of the present application includes additional implementations, in which the functions may be performed in a substantially simultaneous manner or in the reverse order depending on the functions involved, in accordance with the illustrated or discussed order. It will be understood by those skilled in the art to which the embodiments of the present application pertain.

The logic and/or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be embodied in any computer readable medium, used in conjunction with, or in conjunction with, an instruction execution system, apparatus, or device (eg, a computer-based system, a system including a processor, or other system that can fetch instructions and execute instructions from an instruction execution system, apparatus, or device) . For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport a program for use in an instruction execution system, apparatus, or device, or in conjunction with such an instruction execution system, apparatus, or device.

The computer readable medium of the embodiments of the present application may be a computer readable signal medium or a computer readable storage medium or any combination of the two. More specific examples of computer readable storage media, at least (non-exhaustive list) include the following: electrical connections (electronic devices) having one or more wires, portable computer disk cartridges (magnetic devices) , random access memory (RAM) , read only memory (ROM) , erasable editable read only memory (EPROM or flash memory) , fiber optic devices, and portable read only memory (CDROM) . In addition, the computer readable storage medium may even be a paper or other suitable medium on which the program may be printed, as it may be optically scanned, for example by paper or other medium, followed by editing, interpretation or, if appropriate, in other suitable manners. Processing is performed to obtain the program electronically and then stored in computer memory.

In an embodiment of the present application, a computer readable signal medium may include a data signal that is propagated in a baseband or as part of a carrier, carrying computer readable program code. Such propagated data signals can take a variety of forms including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the foregoing. The computer readable signal medium can also be any computer readable medium other than a computer readable storage medium, which can transmit, propagate, or transport a program for use in or in connection with an instruction execution system, an input method, or a device.. Program code embodied on a computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical cable, radio frequency (RF) , and the like, or any suitable combination of the foregoing.

It should be understood that portions of the application can be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or combination of the following techniques well known in the art: having logic gates for implementing logic functions on data signals. Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, programmable gate arrays (PGAs) , field programmable gate arrays (FPGAs) , etc.

A person skilled in the art can understand that all or part of the steps carried by the method of the above embodiment can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium., including one or a combination of the steps of the method embodiments.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. An integrated module, if implemented in the form of a software functional module and sold or used as a standalone product, may also be stored in a computer readable storage medium. The storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

The above is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any variation or replacement can be easily conceived by those skilled in the art within the technical scope disclosed in the present application. These should be covered by the scope of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

A 3D printing calibration artifact, wherein the 3D printing calibration artifact is a polyhedron, the polyhedron comprising:

a first face;

a second face, which is perpendicular to the first face;

a third face, which is perpendicular to the first face and the second face, and meets the first face and the second face at one vertex of the polyhedron; and

a fourth face perpendicular to the first face, at least one space diagonal of the polyhedron being in the fourth face, the space diagonal being from disjoint vertices between the second face and the third face;

wherein a pocket or an island is on at least one of the first face, the second face, the third face and the fourth face; the shape of the pocket or island is hemisphere, sphere or polyhedron.
The 3D printing calibration artifact according to claim 1, wherein further comprising a fifth face, being parallel to the first face, and respectively and vertically intersected with the second face, the third face and the fourth face.
The 3D printing calibration artifact according to claim 1, wherein a rectangular pocket is on at least one of the first face, the second face and the third face.
The 3D printing calibration artifact according to claim 3, wherein the central axis of the rectangular pocket is along face diagonal.
The 3D printing calibration artifact according to claim 1, wherein a blind hole is on at least one of the first face, the second face and the third face.
The 3D printing calibration artifact according to claim 2, wherein a blind hole is on the fifth face.
The 3D printing calibration artifact according to claim 1, wherein a rectangular island is on the fourth face.
The 3D printing calibration artifact according to claim 7, wherein the central axis of the rectangular island is along a diagonal of the fourth face.
The 3D printing calibration artifact according to claim 1, wherein further comprising a sixth face, which is offset above the first face and intersected with the fourth face perpendicularly.
The 3D printing calibration artifact according to claim 9, further comprising a cylinder above the sixth face, the lower bottom face of the cylinder being in the sixth face.
The 3D printing calibration artifact according to claim 10, further comprising a sphere above the upper bottom face of the cylinder.
The 3D printing calibration artifact according to claim 11, further comprising a prism between the cylinder and the sphere, which is configured to support the sphere.
The 3D printing calibration artifact according to claim 11, further comprising a flipped L-shaped seventh face and a L-shaped eighth face, wherein the two outer edges of the flipped L-shaped seventh face respectively intersected with the first face horizontally and the third face vertically, and two outer edges of the L-shaped eighth face respectively intersected with the first face horizontally and the second face vertically.
The 3D printing calibration artifact according to claim 1, wherein the sizes of the three edges where the first face, the second face and the third face intersect with each other are the same.
The 3D printing calibration artifact according to claim 14, wherein the sizes of the three edges are all 25mm.
A method for 3D printing calibration, comprising:

performing 3D printing according to a designed 3D model and a designed 3D printing calibration artifact, and obtaining a printed 3D model and a printed 3D printing calibration artifact; wherein the designed 3D printing calibration artifact and the printed 3D printing calibration artifact are the artifact according to any one of claims 1 to 12;

determining an error or errors of the designed 3D model and the printed 3D model according to the designed 3D printing calibration artifact and the printed 3D printing calibration artifact;

calibrating the 3D printing according to the error or errors.
The method according to claim 16, wherein the errors comprise a one-dimensional linear error, selected from the maximum of: a measured length error of the edge where the first face intersects the second face, a measured length error of the edge where the first face intersects the third face, and a measured length error of the edge where the second face intersects the third face.
The method according to claim 16, wherein the 3D printing calibration artifact comprises a rectangular pocket in at least one face, and the errors comprise a two-dimensional linear error.
The method according to claim 16, wherein the first face, the second face and the third face of the 3D printing calibration artifact each comprise a rectangular pocket, and the two-dimensional linear error is selected from the maximum of: the measured length errors of the edges of the rectangular pockets in the first face, the second face and the third face.
The method according to claim 16, wherein the fourth face of the 3D printing calibration artifact comprises a rectangular island, and the errors comprise a three-dimensional linear error, which is the measured length error of the edge of the rectangular island in the fourth face.
The method according to claim 16, wherein the 3D printing calibration artifact comprises a blind hole in at least one face, and the errors comprises a hole diameter error and a two-dimensional curve error; wherein the hole diameter error is the hole diameter error of the blind hole, and the two-dimensional curve error is the measured range of the hole diameter of the blind hole.
The method according to claim 21, wherein the first face, the second face and the third face of the 3D printing calibration artifact each comprise a blind hole, the hole diameter error is chosen from the maximum of the hole diameter errors of blind holes in the first face, the second face and the third face; the two-dimensional curve error is chosen from the widest range of the measured range of blind holes in the first face, the second face and the third face.
The method according to claim 16, wherein the 3D printing calibration artifact comprises a cylinder on one face, and the errors comprise a cylinder diameter error and a two-dimensional curve error; wherein the two-dimensional curve error is the measured range of the cross-sectional diameter of the cylinder.
The method according to claim 16, wherein the 3D printing calibration artifact comprises a sphere on one face, and the errors comprise a sphere diameter error and a three-dimensional curve error; wherein the three-dimensional curve error is the measured range of the diameter of the sphere.
The method according to claim 16, wherein the 3D printing calibration artifact comprises a fifth face parallel to the first face, and the errors comprises a deformation error, which is the measured error between the upper edge and the lower edge in the same face of the polyhedron between the first face and the fifth face.
The method according to any of claims 16 to 25, further comprising: if the error is within an acceptable error range, determining the printability of the material in the 3D printing and the ability of the 3D printer used in the 3D printing.
The method according to claim 16, further comprising:

determining a repeatability error or repeatability errors between any two printed 3D models according to any two printed 3D printing calibration artifact;

evaluating the repeatability of the 3D printing according to the repeatability error or repeatability errors.
A 3D printer comprising:

one or more processors;

a storage device for storing one or more programs;

when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the method of any one of claims 16 to 27.