3D printer and calibration method therefor

Abstract

The present application discloses a 3D printer and a calibration method therefor. The 3D printer comprises: multiple print head assemblies, each print head assembly having a hot end; a calibration block, the calibration block being configured so that when the hot end of each print head assembly comes into contact with the edge of the calibration block, the hot end is displaced away from or toward a distance measuring sensor; and the distance measuring sensor, the distance measuring sensor being configured to acquire the displacement of the hot end relative to the distance measuring sensor.

Description

A 3D printer and its calibration method Technical Field

[0001] This invention relates to the field of 3D printing, and more specifically to 3D printers and their calibration methods. Background Technology

[0002] To obtain high-resolution printed models, the printheads used for printing require precise positional calibration, especially for 3D printers with multiple printheads and replaceable hot ends on the printheads.

[0003] The purpose of multi-head calibration is to compensate for the distance deviation of multiple printheads in the X, Y, and Z axes by measuring the distance deviation values ​​in the X, Y, and Z axes. This ensures that the multiple printheads always maintain the correct relative positions in the X, Y, and Z axes during the printing process, avoiding problems such as color mixing, material mixing, and misalignment between different materials.

[0004] There is a need in this field to develop an improved, faster, more accurate, and more reliable calibration technique, especially a multi-nozzle calibration technique, to mitigate or overcome the aforementioned technical deficiencies and to achieve other beneficial technical effects.

[0005] The information included in this background section of the present invention specification, including any references cited herein and any descriptions or discussions thereof, is included for technical reference purposes only and is not intended to limit the scope of the invention. Summary of the Invention

[0006] The present invention is proposed in view of the foregoing and other further ideas.

[0007] According to one aspect of the present invention, a method for calibrating a 3D printer is proposed, the 3D printer comprising a plurality of printhead assemblies, each printhead assembly having a hot end; a calibration block configured to cause the hot end to displace away from or toward a distance sensor when the hot end of the printhead assembly contacts an edge of the calibration block; and a distance sensor configured to acquire the displacement of the hot end relative to the distance sensor.

[0008] The method includes the following steps:

[0009] The first center coordinates (X1, Y1) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the first print head assembly;

[0010] The second center coordinates (X2, Y2) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the second printhead assembly;

[0011] Based on the difference between the first center coordinates and the second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and

[0012] The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

[0013] In one embodiment, the 3D printer further includes a controller configured to acquire coordinate parameters of the contact position between the hot end and the edge of the calibration block.

[0014] In one embodiment, the printhead assembly further includes a hot end base and a cantilever connecting the hot end and the hot end base.

[0015] In one embodiment, the displacement is a displacement in the Z direction.

[0016] In one embodiment, the calibration block is a hole or a boss, the edge of which forms the edge of the calibration block.

[0017] In one embodiment, the hole is a through hole or a blind hole.

[0018] In one embodiment, the calibration block is arranged in a circle, with the center of the calibration block being the center of the circle.

[0019] In one embodiment, the coordinate values ​​(x1, y1), (x2, y2), and (x3, y3) of the three contact points on the circumference of the circle are obtained by the first print head assembly and the second print head assembly respectively. The coordinate values ​​(X, Y) of the first and second center points of the calibration block are then calculated using the following formula:

[0020]

[0021] in,

[0022] a1=(x1 2 -x2 2 +y1 2 -y2 2 ) / 2

[0023] a2=(x1 2 -x3 2 +y1 2 -y3 2 ) / 2.

[0024] In one embodiment, the calibration block is arranged in a square shape, and the first center coordinates (X1, Y1) of the calibration block are obtained by the first print head assembly contacting four contact positions located on the four sides of the square respectively.

[0025] The second center coordinates (X2, Y2) of the calibration block are obtained by the second printhead assembly contacting four contact positions located on the four sides of the square.

[0026] Two x-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the left and right sides of the square, respectively. 左 and x 右 ;

[0027] Two y-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the upper and lower sides of the square, respectively. 上 and y 下 ;and

[0028] The first and second center coordinate values ​​(X, Y) of the calibration block are calculated using the following formulas:

[0029] X = (x 左 + x 右 ) / 2, Y = (y 上 + y 下 ) / 2.

[0030] In one embodiment, the method further includes the following steps:

[0031] Make the hot end of the first print head assembly contact the calibration point of the printing platform to obtain the z-coordinate value z1 corresponding to the first print head assembly; make the hot end of the second print head assembly contact the calibration point to obtain the z-coordinate value z2 corresponding to the second print head assembly, thereby obtaining the height difference Δm = z1 - z2 between the first print head assembly and the second print head assembly.

[0032] According to another concept of the present invention, a 3D printer is proposed, the 3D printer comprising:

[0033] Multiple printhead assemblies, each printhead assembly having a hot end;

[0034] A calibration block, configured to cause the hot end of the printhead assembly to displace away from or toward the ranging sensor when the hot end of the printhead assembly contacts the edge of the calibration block;

[0035] A ranging sensor, configured to acquire the displacement of the hot end relative to the ranging sensor; and

[0036] A controller configured to acquire coordinate parameters of the contact position between the hot end and the edge of the calibration block, and the controller further configured to control the 3D printer to perform the following steps:

[0037] The first center coordinates (X1, Y1) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the first print head assembly;

[0038] The second center coordinates (X2, Y2) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the second printhead assembly;

[0039] Based on the difference between the first center coordinates and the second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and

[0040] The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

[0041] In one embodiment, the printhead assembly further includes a hot end base and a cantilever connecting the hot end and the hot end base.

[0042] In one embodiment, the displacement is a displacement in the Z direction.

[0043] In one embodiment, the calibration block is a hole or a boss, the edge of which forms the edge of the calibration block.

[0044] In one embodiment, the hole is a through hole or a blind hole.

[0045] In one embodiment, the calibration block is arranged in a circle, with the center of the calibration block being the center of the circle.

[0046] In one embodiment, the coordinate values ​​(x1, y1), (x2, y2), and (x3, y3) of the three contact points on the circumference of the circle are obtained by the first print head assembly and the second print head assembly respectively. The coordinate values ​​(X, Y) of the first and second center points of the calibration block are then calculated using the following formula:

[0047]

[0048] in,

[0049] a1=(x1 2-x2 2 +y1 2 -y2 2 ) / 2

[0050] a2=(x1 2 -x3 2 +y1 2 -y3 2 ) / 2.

[0051] In one embodiment, the calibration block is arranged in a square shape, and the first center coordinates (X1, Y1) of the calibration block are obtained by the first print head assembly contacting four contact positions located on the four sides of the square respectively.

[0052] The second center coordinates (X2, Y2) of the calibration block are obtained by the second printhead assembly contacting four contact positions located on the four sides of the square.

[0053] Two x-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the left and right sides of the square, respectively. 左 and x 右 ;

[0054] Two y-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the upper and lower sides of the square, respectively. 上 and y 下 ;and

[0055] The first and second center coordinate values ​​(X, Y) of the calibration block are calculated using the following formulas:

[0056] X = (x 左 + x 右 ) / 2, Y = (y 上 + y 下 ) / 2.

[0057] In one embodiment, the method further includes the following steps:

[0058] Make the hot end of the first print head assembly contact the calibration point of the printing platform to obtain the z-coordinate value z1 corresponding to the first print head assembly; make the hot end of the second print head assembly contact the calibration point to obtain the z-coordinate value z2 corresponding to the second print head assembly, thereby obtaining the height difference Δm = z1 - z2 between the first print head assembly and the second print head assembly.

[0059] Further embodiments of the present invention can achieve other advantageous technical effects not listed hereafter, which may be partially described below and can be expected and understood by those skilled in the art after reading the present invention. Attached Figure Description

[0060] The above-described features and advantages of these embodiments, as well as other features and advantages, and the ways in which they are implemented, will become more apparent from the following description in conjunction with the accompanying drawings, and embodiments of the invention will be better understood.

[0061] Figure 1 is a schematic diagram of the print head assembly of the 3D printer of this application;

[0062] Figure 2 is a schematic diagram of the printing platform and hot end of the 3D printer of this application in one embodiment;

[0063] Figure 3 is a schematic diagram of the printing platform and hot end of the 3D printer of this application in one embodiment;

[0064] Figure 4 is a force diagram of the hot end of this application in one embodiment;

[0065] Figure 5 is a force diagram of the hot end of this application in one embodiment; and

[0066] Figure 6 is a force diagram of the hot end of this application in one embodiment. Detailed Implementation

[0067] In the following description of the accompanying drawings and detailed embodiments, details of one or more embodiments of the invention will be set forth. Other features, objects, and advantages of the invention will become apparent from these descriptions, drawings, and claims.

[0068] It should be understood that the illustrated and described embodiments are not limited in application to the details of the construction and arrangement of the components set forth in the following description or illustrated in the drawings. The illustrated embodiments may be other embodiments and can be implemented or performed in various ways. The examples are provided by way of explanation rather than limitation of the disclosed embodiments. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the invention without departing from the scope or spirit of the disclosure. For example, features illustrated or described as part of one embodiment may be used with another embodiment to still produce another embodiment. Therefore, this disclosure covers such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0069] Similarly, it is understood that the phrases and terms used in this document are for descriptive purposes and should not be considered restrictive. The use of “including,” “contains,” or “has,” and their variations, in this document is intended to include, in an open-ended manner, the items listed thereafter, their equivalents, and any additional items.

[0070] The term "3D printer" includes not only three-dimensional printing equipment in the general sense of the art, such as industrial-grade 3D printers, including consumer-grade 3D printers, but also laser processing equipment with 3D printing capabilities and 3D printing equipment with laser processing capabilities, all of which fall within the scope of "3D printer" in this application.

[0071] In this application, a "3D printer" may include not only the function of constructing objects by layering together powdered metal or plastic and other bondable materials through methods such as spraying adhesive or extrusion to form three-dimensional solids, but may also selectively include laser processing functions depending on the application. For example, laser processing may include laser cutting, engraving, burning, and laser ablation. The aforementioned term "engraving" refers to the process by which a 3D printer changes the appearance of a material without cutting through it. For example, for a laser cutting machine, it could mean removing some material from the surface, or changing the color of the material by applying electromagnetic radiation, and so on.

[0072] As used herein, the terms “first,” “second,” etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with “first,” “second,” etc., may explicitly or implicitly include one or more of that feature. In this document, “multiple” means two or more, unless otherwise explicitly specified.

[0073] As used herein, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this document according to the specific circumstances.

[0074] The present invention will now be described in more detail with reference to specific embodiments thereof.

[0075] 3D printer

[0076] A 3D printer has a printing platform or printing table. The printing platform theoretically defines an xy-plane, which is bounded by the x-axis and y-axis. The x-axis, y-axis, and z-axis are perpendicular to each other. The term "movement along an axis," such as along the x-axis, y-axis, or z-axis, means movement parallel to or along the same straight line as that axis. In this document, the orientations specified by the x-axis, y-axis, or z-axis are for convenience of discussion only and do not constitute any limitation on the orientation. Of course, those skilled in the art will appreciate that the printing platform can be connected to x-axis, y-axis, or z-axis motion modules, and this is not limited herein. Additionally, the printing platform has a heating function and can be a single piece of material or composed of multiple layers of material connected in a detachable or non-detachable manner. The printing platform of a 3D printer is used to place the material to be printed, the substrate, etc. The printing platform provides a working surface that is as flat as possible. The printing platform defines the range of motion of the print head.

[0077] The 3D printer may include x-axis, y-axis, and z-axis motion modules, a printing platform, and drive motors corresponding to the x-axis, y-axis, and z-axis motion modules. For example, the x-axis and y-axis motion modules (generally with or including drive motors or actuators) may be operatively connected to the print head, controlling the print head's movement along the x-axis and y-axis, respectively. The z-axis motion module (generally with or including drive motors or actuators) may be connected to the printing platform, controlling the printing platform's movement along the z-axis. However, the 3D printer of this application is not limited to this configuration; for example, the print head may also be connected to the x-axis, y-axis, and z-axis motion modules.

[0078] As shown in Figures 1 to 3, the 3D printer includes: multiple printhead assemblies 1, each printhead assembly having a hot end 11 and a hot end base 12 for fixing the hot end 11; a calibration block 21 configured to cause displacement of the hot end 11 when it contacts the edge of the calibration block 21; and a distance sensor 13 configured to acquire the displacement of the hot end 11 relative to the distance sensor 13. The distance sensor 13 can be a sensor such as an inductor coil that can detect minute deformations or minute changes in distance. The distance sensor 13 can be disposed on the printhead assembly 1 and positioned opposite the hot end 11. When the hot end 11 undergoes minute deformation or a minute change in distance due to force, it can be detected by the distance sensor 13.

[0079] As shown in Figures 1 to 3, the printhead assembly 1 also has a cantilever 14. The hot end 11 and the hot end base 12 are connected by the cantilever 14. When the hot end 11, specifically the printhead or nozzle tip 111, contacts the edge of the calibration block 21, the cantilever 14 deforms and causes the hot end 11 to displace. The hot end base 12 can be connected to one end of the cantilever 14, so that when the nozzle tip 111 of the hot end 11 contacts the edge of the calibration block 21, the cantilever 14 deforms away from or toward the ranging sensor 13 with the end connected to the hot end base 12 as the fulcrum, and displaces in the Z direction.

[0080] As shown in Figures 2 and 3, the contact is primarily achieved through the nozzle tip 111 of the hot end 11 contacting the edge of the calibration block 21. Since both the hot end 11 and the calibration block 21 are rigid, the hot end 11 will undergo minute deformation and displacement when they come into contact. The ranging sensor 13 can detect this minute deformation and displacement, thereby obtaining the displacement of the hot end 11 relative to the ranging sensor 13.

[0081] As shown in Figures 2 and 3, the calibration block 21 can be a hole disposed on the printing platform 2. The hole can be a through hole or a blind hole. In one embodiment, the calibration block 21 can be circular, with its center at the center of the circle. Alternatively, the calibration block 21 can be a portion of a circle, such as an arc. In another embodiment, the calibration block 21 can also be a boss, wherein the edge of the hole or the boss forms the edge of the calibration block 21. Of course, the calibration block 21 can also be other shapes, and the above is not a limitation on the shape of the calibration block 21. For example, in one embodiment, the calibration block 21 can be square. Alternatively, the calibration block 21 can also be an independent element of the printing platform 2, rather than being disposed on the printing platform 2.

[0082] As shown in Figure 4, when the nozzle tip 111 contacts the calibration block 21 and is subjected to an upward force F (as indicated by the arrow), the cantilever 14 deforms as shown by the arrow, causing the distance L between the hot end 11 and the ranging sensor 13 to decrease, resulting in displacement of the hot end 11. As shown in Figure 5, when the nozzle tip 111 contacts the calibration block 21 and is subjected to a leftward force F (as indicated by the arrow), the cantilever 14 deforms as shown by the arrow, causing the distance L between the hot end 11 and the ranging sensor 13 to increase, resulting in displacement of the hot end 11. As shown in Figure 6, when the nozzle tip 111 contacts the calibration block 21 and is subjected to a rightward force F (as indicated by the arrow), the cantilever 14 deforms as shown by the arrow, causing the distance L between the hot end 11 and the ranging sensor 13 to decrease, resulting in displacement of the hot end 11. The principle of this application is to use the ranging sensor 13 to detect the displacement change of the hot end 11, thereby knowing the contact between the nozzle tip 111 and the calibration block 21 and obtaining the coordinate parameters of the contact position between the hot end 11 and the edge of the calibration block 21.

[0083] The 3D printer may also include a controller (not shown), configured to acquire coordinate parameters of the contact position between the hot end 11 and the edge of the calibration block 21, and to control the 3D printer to perform the following steps:

[0084] The first center coordinates (X1, Y1) of the calibration block 21 are obtained by contacting at least three points on the edge of the first print head assembly with the calibration block 21.

[0085] The second center coordinates (X2, Y2) of the calibration block 21 are obtained by contacting at least three points on the edge of the second print head assembly with the calibration block 21.

[0086] Based on the difference between the first and second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and

[0087] The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

[0088] The above method determines the center coordinates by the contact positions of three points where the hot end 11 touches the edge of the calibration block 21. Similarly, the center coordinates can be calculated by touching four, five, six or more contact points and combining the coordinates of different points. The center coordinates here represent the geometric center of the calibration block 21.

[0089] X and Y axis calibration methods

[0090] The 3D printer includes multiple printhead assemblies 1, each printhead assembly having a hot end 11 and a hot end base 12 for fixing the hot end 11; a calibration block 21 configured to displace the hot end 11 when it contacts the edge of the calibration block 21; a distance sensor 13 configured to detect deformation and acquire the displacement change of the hot end 11 relative to the distance sensor 13; and a controller configured to acquire coordinate parameters of the contact position between the hot end 11 and the edge of the calibration block 21, and the controller is further configured to control the 3D printer to perform the following steps:

[0091] The first center coordinates (X1, Y1) of the calibration block 21 are obtained by contacting at least three points on the edge of the first print head assembly with the calibration block 21.

[0092] The second center coordinates (X2, Y2) of the calibration block 21 are obtained by contacting at least three points on the edge of the second print head assembly with the calibration block 21.

[0093] Based on the difference between the first and second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and

[0094] The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

[0095] The calibration block 21 can be set as a circle, with the center of the calibration block 21 being the center of the circle.

[0096] Specifically, the coordinate values ​​(x1, y1), (x2, y2), and (x3, y3) of the three contact points are obtained by the first and second printhead assemblies contacting the three points on the circumference of the circle, respectively. The coordinate values ​​(X, Y) of the first and second center points of the calibration block 21 are then calculated using the following formulas:

[0097]

[0098]

[0099] in,

[0100] a1=(x1 2 -x2 2 +y1 2 -y2 2 ) / 2

[0101] a2=(x1 2 -x3 2 +y1 2 -y3 2 ) / 2.

[0102] In another embodiment, the calibration block 21 is configured as a square, and the first center coordinates (X1, Y1) of the calibration block are obtained by the first print head assembly contacting four contact positions located on the four sides of the square respectively.

[0103] The second center coordinates (X2, Y2) of the calibration block are obtained by the second printhead assembly contacting four contact positions located on the four sides of the square.

[0104] Two x-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the left and right sides of the square, respectively. 左 and x 右 ;

[0105] Two y-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the top and bottom sides of the square, respectively. 上 and y 下 ;and

[0106] The first and second center coordinate values ​​(X, Y) of the calibration block are calculated using the following formulas:

[0107] X = (x 左 + x 右 ) / 2, Y = (y 上 + y 下 ) / 2.

[0108] Z-axis calibration method

[0109] The Z-axis calibration method includes the following steps:

[0110] Make the hot end 11 of the first print head assembly contact the calibration point of the printing platform 2 to obtain the z-coordinate value z1 corresponding to the first print head assembly; make the hot end 11 of the second print head assembly contact the calibration point to obtain the z-coordinate value z2 corresponding to the second print head assembly, thereby obtaining the height difference Δm = z1 - z2 between the first print head assembly and the second print head assembly.

[0111] The calibration point can be set on calibration block 21 or on printing platform 2.

[0112] The foregoing description of several embodiments of the invention has been provided for illustrative purposes. The foregoing description is not intended to be exhaustive, nor is it intended to limit the invention to the precise steps and / or forms disclosed; clearly, many modifications and variations can be made in light of the teachings above. The scope of the invention and all its equivalents are intended to be defined by the appended claims.

Claims

1. A method for calibrating a 3D printer, characterized in that, The 3D printer includes multiple printhead assemblies, each printhead assembly having a hot end; and a calibration block configured to cause the hot end of the printhead assembly to displace away from or toward the distance sensor when the hot end of the printhead assembly contacts the edge of the calibration block. and a ranging sensor, the ranging sensor being configured to acquire the displacement change of the hot end relative to the ranging sensor. The method includes the following steps: The first center coordinates (X1, Y1) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the first print head assembly; The second center coordinates (X2, Y2) of the calibration block are obtained by contacting at least three points on the edge of the calibration block with the second printhead assembly; Based on the difference between the first center coordinates and the second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

2. The method according to claim 1, characterized in that, The printhead assembly also has a hot end base and a cantilever connecting the hot end and the hot end base.

3. The method according to claim 2, characterized in that, The calibration block is a hole or a boss, and the edge of the hole or boss forms the edge of the calibration block.

4. The method according to claim 3, characterized in that, The calibration block is arranged in a circle, with its center at the center of the circle. The coordinates (x1, y1), (x2, y2), and (x3, y3) of the three contact points on the circumference of the circle are obtained through the contact between the first and second printhead assemblies and these three points. The coordinates (X, Y) of the first and second center points of the calibration block are then calculated using the following formulas: in, a1=(x1 2 -x2 2 +y1 2 -y2 2 ) / 2 a2 = (x1 2 -x3 2 +y1 2 -y3 2 ) / 2.

5. The method according to claim 3, characterized in that, The calibration block is square, and the first center coordinates (X1, Y1) of the calibration block are obtained by the first print head assembly contacting four contact positions located on the four sides of the square. The second center coordinates (X2, Y2) of the calibration block are obtained by the second printhead assembly contacting four contact positions located on the four sides of the square. Two x-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the left and right sides of the square, respectively. 左 and x 右 ; Two y-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the upper and lower sides of the square, respectively. 上 and y 下 ;and The first and second center coordinate values ​​(X, Y) of the calibration block are calculated using the following formulas: X = (x 左 + x 右 ) / 2, Y = (y 上 + and 下 ) / 2.

6. The method according to any one of claims 4 or 5, characterized in that, The method further includes the following steps: Make the hot end of the first print head assembly contact the calibration point to obtain the z-coordinate value z1 corresponding to the first print head assembly; make the hot end of the second print head assembly contact the calibration point to obtain the z-coordinate value z2 corresponding to the second print head assembly, thereby obtaining the height difference Δm = z1 - z2 between the first print head assembly and the second print head assembly.

7. A 3D printer, characterized in that, The 3D printer includes: Multiple printhead assemblies, each printhead assembly having a hot end; A calibration block configured to cause the hot end of the printhead assembly to displace away from or toward the ranging sensor when the hot end of the printhead assembly contacts the edge of the calibration block; A ranging sensor, configured to acquire the displacement change of the hot end relative to the ranging sensor; and A controller configured to acquire coordinate parameters of the contact position between the hot end and the edge of the calibration block, and the controller further configured to control the 3D printer to perform the following steps: Control the first printhead assembly to make contact with at least three contact points on the edge of the calibration block, and obtain the first center coordinates (X1, Y1) of the calibration block; The second printhead assembly is controlled to contact at least three points on the edge of the calibration block to obtain the second center coordinates (X2, Y2) of the calibration block; Based on the difference between the first center coordinates and the second center coordinates, the coordinate deviation (ΔX, ΔY) of the second printhead assembly relative to the first printhead assembly is obtained; and The x and y coordinate values ​​of the second printhead assembly are compensated based on the coordinate deviation (ΔX, ΔY).

8. The 3D printer according to claim 7, characterized in that, The printhead assembly also has a hot end base and a cantilever connecting the hot end and the hot end base.

9. The 3D printer according to claim 8, characterized in that, The calibration block is a hole or a boss, and the edge of the hole or boss forms the edge of the calibration block.

10. The 3D printer according to claim 9, characterized in that, The calibration block is arranged in a circle, with its center at the center of the circle. The coordinates (x1, y1), (x2, y2), and (x3, y3) of the three contact points on the circumference of the circle are obtained through the contact between the first and second printhead assemblies and these three points. The coordinates (X, Y) of the first and second center points of the calibration block are then calculated using the following formulas: in, a1=(x1 2 -x2 2 +y1 2 -y2 2 ) / 2 a2 = (x1 2 -x3 2 +y1 2 -y3 2 ) / 2.

11. The 3D printer according to claim 10, characterized in that, The calibration block is square, and the first center coordinates (X1, Y1) of the calibration block are obtained by the first print head assembly contacting four contact positions located on the four sides of the square. The second center coordinates (X2, Y2) of the calibration block are obtained by the second printhead assembly contacting four contact positions located on the four sides of the square. Two x-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the left and right sides of the square, respectively. 左 and x 右 ; Two y-coordinate values ​​are obtained through the contact between the first and second printhead assemblies and the upper and lower sides of the square, respectively. 上 and y 下 ;and The first and second center coordinate values ​​(X, Y) of the calibration block are calculated using the following formulas: X = (x 左 + x 右 ) / 2, Y = (y 上 + and 下 ) / 2.

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