WO2018069749A1

WO2018069749A1 - A multiple head three dimensional printer

Info

Publication number: WO2018069749A1
Application number: PCT/IB2016/056134
Authority: WO
Inventors: Juris Klava
Original assignee: Juris Klava
Priority date: 2016-10-13
Filing date: 2016-10-13
Publication date: 2018-04-19

Abstract

The present invention relates to additive manufacturing printers, especially to extrusion-based three dimensional (3D) printers comprising plurality of printing heads. The 3D printer comprises a frame structure (1), a working platform (2), a Z axis guide (3), a horizontal beam (10), and at least two delta robots (20). At least two delta robots (20) are positioned so that one linkage (22) of at least one delta robot (20) is positioned in a space between the two linkages (22) of adjacent delta robot (20), in result of which a working areas (25A) of at least two printing heads (25) of at least two delta robots (20) interlap allowing simultaneous work of at least two printing heads (25) in a working area (25 A) of at least one printing head (25).

Description

A MULTIPLE HEAD THREE DIMENSIONAL PRINTER

Technical Field The present invention relates to additive manufacturing printers, especially to extrusion-based three dimensional (3D) printers comprising plurality of printing heads.

Background Art In the field of additive manufacturing one of the main objectives is to increase a printing speed and a printing volume. Multiple designs exist in aim to reach the given targets.

United States patent No. 8944802 discloses a fused filament fabrication printer, which uses a plurality of fixed printing heads mounted to a structure over a build platform on which the model is built by constructing each layer of the model as the build platform is indexed through a multiplicity of successive print planes.

Chinese patent application publication No. CN204773597 discloses a nested 3D printer which comprises hybrid Cartesian and delta manipulator. International patent application publication No. WO2014/028828 discloses additive manufacturing system with extended printing volume, which implements a conveyor belt, which moves as a part being printed.

Usually, the printing volume is increased by creating bigger 3D printers, which certainly increases the build volume but not the printing speed.

The aim of the invention is to create a 3D printer with increased build volume and printing speed as well as with high resolution. Summary of the Invention

The aim is reached by designing a three dimensional (3D) printer comprising: a frame structure; a working platform arranged in the lower part of the frame structure and on which an object can be printed; a Z axis guide as a part of the frame structure and configured to provide a Z axis movement; a horizontal beam attached to the Z axis guide; and at least two delta robots.

The frame structure can be any frame structure which is able to carry axis guides and other elements to the printer. For example the working platform or the Z axis guide can be as a part of the frame structure.

The delta robot comprises at least one base member, at least three linkages, where each linkage comprises an actuator and an arm connecting to each other forming said linkage, and a printing head. The similar delta robot is disclosed in the United States patent publication No. 4,976,582.

The distinguishing feature of the invention is that at least two delta robots are positioned so that one linkage of at least one delta robot is positioned in a space between the two linkages of adjacent delta robot, in result of which a working areas of at least two printing heads of at least two delta robots interlap allowing simultaneous or sequential work of at least two printing heads in a common working area formed from two adjacent overlapping working areas. This feature allows the printing head of at least one delta robot to enter the working area of adjacent delta robot or robots in a case where more than two delta robots are merged. The collisions of linkages of adjacent delta printers is avoided, firstly, by the above mentioned arrangement of linkages and, secondly, by implementing collision avoidance system known in art. The two printing heads of adjacent delta robots create common working area allowing simultaneous work on one object to be printed. This enables parallel material printing with increased printing speed, while printing heads using different materials permit the simultaneous or sequential deposition of those materials onto the working platform or printed object.

Each working area of each delta robot is in the form of a circle in two dimensions and cylindrical build are in three dimensions. The common working area of two delta printers is shaped like a symmetric lens (intersection region of two circles). If the delta robots of different scale are chosen then the common working are will be shaped like an asymmetric lens. The printing heads can be equipped with other end-effectors such as measurement probes or even with milling heads or laser engraving heads. The result can be a hybrid manufacturing machine comprising features of additive manufacturing (3D printing) and subtractive manufacturing (milling, laser machining, water jet) as well as including quality control features (measuring probes, laser scanner).

In another embodiment the 3D printer can comprise a set of nine delta robots. Nine delta robots are connected to common cluster platform via its base members. Each of said delta robots interlaps with adjacent delta robots in such way that at least one linkage of one delta robot (20) is positioned in a space between two linkages of adjacent delta robot, in result of which adjacent delta robots overlap each others working areas, creating single working area. The delta robot positioned in the middle of the set of nine delta robots can enter with its printing head in working areas of all the delta robots positioned around. In the meantime, each of delta printers positioned around the centre delta printer can enter with its printing head centre delta printer working area. In given situation simultaneous work of nine printing heads drastically increases a printing speed compared to known single head systems.

In another embodiment the 3D printer can be equipped with a C axis motor attached to the cluster platform and configured to rotate said cluster platform around its vertical axis (Z axis). The following feature is very useful when the printing head of at least one delta robot is configured to extrude material, which is different in its properties from extruded material from other printing heads of the delta robots of the printer and therefore switch between the materials is needed. In another embodiment a relative rotation of the printing heads relative to the build platform can be accomplished by rotating build platform.

In more simple embodiments of the invention, the 3D printer comprises only the Z axis guide. The delta printer are attached to the Z axis guide via the horizontal beam or cluster. The cluster can be in the form of horizontal beam. Additionally, the horizontal beam can comprise an X axis guide which is configured to move the attached cluster platform or the delta printer/-s along an X axis.

The three dimensional printer further comprises an Y axis guide as a part of the frame structure and/or the working platform and configured to move the frame structure along an Y axis. The axis are positioned in the 3D printer according the same system as it is in Computer Numerical Control (CNC) machines - a Z axis is perpendicular to the working platform; a Y axis is parallel to working platform and perpendicular to the Z axis; and an X axis is parallel to the working platform and the Y axis and perpendicular to Z and Y axis. Axis guide may comprise any linear drive mechanism such as lead screw mechanism, magnetic guides or any other means that are able to provide linear motion.

The general concept of the invention is that the said X, Y, Z axis guides create the so called Cartesian coordinate robot in which at least two delta robots are built in. Moreover, theses delta robots are positioned so that the at last one linkage of the delta robot is positioned in the space between two linkages of adjacent delta robot.

The 3D printer can further comprise a tilting device attached to the base member of the delta robot and configured to provide tilting of said delta robot around its X and Y axis.

The present invention also comprises a method for the movement and positioning of at least two delta robots in the 3D printer. The method comprises a step for movement of at least two delta robots together in a such a way that one of three linkages of at least one delta robot is positioned in a space between the two linkages of the three linkages of adjacent delta robot, in result of which a working areas of at least two printing heads of at least two delta robots interlap or overlay creating common working area and allowing simultaneous and/or sequential work of at least two printing heads within the common working area. The invention further comprises a method for three dimensional (3D) printing using aforementioned 3D printer and aforementioned method for the movement and positioning of at least two delta robots of the 3D printer. The method comprises multiple steps, wherein the first step is providing a digital object model to be printed, preferably in *.stl format. Any other format used digital manufacturing is suitable. The next step includes determining a size of the object model and amount of delta robots with printing heads to be used for printing the object model. Each delta robot can print certain area. Accordingly, the method determines how much printing areas of existing delta robots are taken by object model. In result of which a necessary amount of delta robots is determined based of the size or area of object model. The object model is sliced in predetermined layers using existing 3D slicing techniques. Each sliced layer is divided or separated into sub-layers wherein each sublayer is assigned to certain delta robot, which will print said sub-layer. An area of each sub-layer is equal or smaller than working or printing area of each delta robot. The printing areas define the area of each sub-layer. Knowing the printing areas of each delta robot an area of each sub-layer can be defined. Finally, the object model is printed using assigned delta robots with printing heads, wherein each delta robots prints its assigned sub-layer.

The object model can be provided in the form of a G-code, which is then post processed. The g-code by itself using toolpath data describes the shape of the object or model to be printed. The post processing includes determination of area and/or volume of the object to be printed and determining the necessary amount of delta printers to be used for printing according to the aforementioned method.

The present invention allows to create objects by 3D printing which are much larger than printing area of one separate printing head and to create object without assembly features as described in the US patent publication No. US 8,944,802.

Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief description of the drawings

Fig. 1 is a perspective view of a three dimensional (3D) printer comprising two printing heads

25 with indicated working areas 30 of each printing head 25.

Fig. 2 is a perspective view of a three dimensional (3D) printer comprising two printing heads

25 with indicated working areas 30 of each printing head 25, wherein one linkage 22 of delta robot 20 is positioned within a space of two linkages 22 of adjacent delta robot 20.

Fig. 3 is a perspective view of the 3D printer comprising four delta robots 20 where two delta robots 20 are positioned together but two delta robots 20 are positioned separately.

Fig. 4 is a perspective view of the 3D printer comprising four delta robots 20 with printing heads 25 positioned together and with indicated working areas 30 of each printing head 25.

Fig. 5 is a perspective view of the 3D printer comprising nine delta robots 20 with printing heads 25. Fig. 6 is a top view of the 3D printer comprising nine printing heads 25 with indicated printing or working areas 30 of each printing head 25 as well as an overall working area. Fig. 7 is a perspective view of the 3D printer comprising multiple delta robots 20 for additive manufacturing.

Fig. 8 is a schematic view of one embodiment of positioning delta robots 20, illustrating working areas 30 of two adjacent delta robots 20, wherein two working areas 30 forming overlapping or common working area 31.

Fig. 9 is a schematic view of another embodiment for positioning adjacent delta robots 20. Fig. 10 is a schematic view illustrating a positioning configuration of multiple delta robots 20 into a cluster.

Referring to Fig. 1 and Fig. 2, the three dimensional (3D) printer comprises a frame structure 1, where part of the frame structure 1 is a working platform 2 arranged in the lower part of the frame structure 1 and on which an object can be printed or built. The 3D printer further comprises a Z-axis guide 3 as a part of the frame structure 1 and configured to provide a Z- axis movement Z. The Z-axis movement is provided by Z-axis guide 3, which is designed as a lead screw mechanism (not shown in Figs). A horizontal beam 10 is attached to the Z-axis guide 3. A horizontal beam 10 is provided with the X-axis guide 5 that comprises a lead screw mechanism (not shown in Figs) to provide an X-axis movement X of two delta robots 20 attached to the horizontal beam 10.

Optionally, the frame structure 1 of the 3D printer can further comprise Y-axis guide 7 for providing Y-axis movement Y for the part of the frame structure 1, which forms Z-axis guide 3 and X-axis guide 5.

Each delta robot 20 attached to the horizontal beam 10 comprises a base member 21, three linkages 22, where each linkage 22 comprises an actuator 23 and an arm 24 which are connected to each other forming said linkage 22, and a printing head 25 at the one end of all three linkages 22. The actuator 23 is attached to the motor 26, preferably stepper 26 or any other known activation device, to provide rotation of said actuator 23. The delta robot 20 further comprises an attachment 27, which attaches the delta robot 20 to the X-axis guide 5. Hence, both delta robots 20 can move along the X-axis. The delta robots 20 are configured so that when they are moved together they are positioned so that one linkage 22 of at least one delta robot 20 is arranged in a space between the two linkages 22 of adjacent delta robot 20 (as shown in Figs. 2 to 10), in result of which a working areas 30 of two printing heads 25 of two delta robots 20 interlap allowing simultaneous work of two printing heads 25 in a common working area 31.

Figs. 3 and 4 illustrate an embodiment with four delta robots 20 which can work in a position when none of the linkages 22 of the delta robots 20 is in are between two linkages of the adjacent delta robots 20. But in the mean time the 3D printer can be configured so that the delta robots 20 are moved together so close that at least one linkage 22 of one delta robot 20 is positioned between the two linkages 22 of adjacent delta robot 20 creating common working area 31 from multiple working areas 30.

Figs 5 and 6 illustrate another embodiment of the 3D printer having nine delta robots 20. The delta robots 20 are arranged so that each delta printer 20 is positioned partly in the area of the adjacent delta robot 20.

In another embodiment the 3D printer comprises five horizontal beams 10 on which multiple delta robots 20 are arranged (see Fig. 7). One horizontal beam 10 comprises a cluster of nine delta robots 20, but another horizontal beam comprises two clusters of four delta robots 20. Following embodiment illustrates infinite possibilities to configure the 3D printer with multiple delta robots 20 which can enter each others working areas 30 creating common working areas 31, allowing to print large scale objects or multiple object in one set-up. The delta robots 20 are preferably arranged in two possible configurations (Figs. 8 and 9). Using one of said arrangement configurations the delta robots 20 can be arranged in clusters containing multiple delta robots or delta printers 20. One configuration resembles a positioning of Ys in a row where each adjacent Y is turned upside down (see Fig. 8). Another configuration resemble a positioning of Ys onto each other (see Fig. 9). Combining aforementioned two configurations a large-scale device with a cluster of delta printers can be designed (see Fig. 10) without any scaling restrictions. While the inventions have been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. Therefore, it is intended that the inventions not be limited to the particular embodiments disclosed herein.

Claims

1. A three dimensional (3D) printer comprising:

- a frame structure (1);

- a working platform (2) arranged in the lower part of the frame structure (1) and on which an object can be printed;

- a Z axis guide (3) as a part of the frame structure (1) and configured to provide a Z axis (Z) movement;

- a horizontal beam (10) attached to the Z axis guide (3);

- at least two delta robots (20), wherein each delta robot (20) comprises at least one base member (21), at least three linkages (22), where each linkage (22) comprises an actuator (23) and an arm (24) connecting to each other forming said linkage (22), and a printing head (25),

wherein at least two delta robots (20) configured to be positioned so that one linkage (22) of at least one delta robot (20) is positioned in a space between the two linkages (22) of adjacent delta robot (20), in result of which a working areas (30) of at least two printing heads (30) of at least two delta robots (20) interlap allowing simultaneous and/or sequential work of at least two printing heads (25) in a common working area (31).

2. The 3D printer according to Claim 1, characterized in that it comprises a set of nine delta robots (20) attached to a cluster platform (11) via its base members (21), wherein each of delta robots (20) interlaps with adjacent delta robots (20) in such way that at least one linkage (22) of one delta robot (20) is positioned in a space between two linkages (22) of adjacent delta robot (20), in result of which adjacent delta robots (20) overlap each others working areas (25 A) creating common working areas (31).

3. The 3D printer according to Claim 1 or 2, characterized in that it further comprises a C axis motor (4) attached to the cluster platform (11) and configured to rotate said cluster platform (11) around its vertical axis (Z).

4. The 3D printer according to Claim 3, characterized in that a C axis motor (4) is attached to the build platform (2) and configured to rotate said build platform around it vertical axis (Z).

5. The 3D printer according to any one of the proceeding Claims, characterized in that the horizontal beam (10) comprises an X-axis guide (5) which is configured to move the attached cluster platform (11) or the delta robot (20) along an X-axis (X).

6. The 3D printer according to any one of the proceeding Claims, characterized in that it further comprises a Y-axis guide (7) as a part of the frame structure (1) and/or the working platform (2) and configured to move the frame structure (1) along a Y-axis (Y).

7. The 3D printer according to any one of the proceeding Claims, characterized in that it further comprises a tilting device attached to the base member (21) of the delta robot (20) and configured to provide tilting of said delta robot (20) around its X and Y axis (X, Y).

8. The 3D printer according to any one of the proceeding Claims, characterized in that the printing head (25) of at least one delta robot (20) is configured to extrude material which is different in its properties from extruded material from other printing heads (25) of the delta robots (20) of the printer.

9. A method for the movement and positioning of at least two delta robots (20) in a 3D printer according to any one of Claims 1-8, characterized in that the method comprises a step of movement of at least two delta robots (20) together in a such a way that one linkage (22) of at least one delta robot (20) is positioned in a space between the two linkages (22) of adjacent delta robot (20), in result of which a working areas (30) of at least two printing heads (25) of at least two delta robots (20) interlap creating common working area (31) and allowing simultaneous and/or sequential work of at least two printing heads (25) within common working area (31).

10. A method for three dimensional (3D) printing using a three dimensional (3D) printer according to any one of Claims 1-8 and a method for the movement and positioning of at least two delta robots (20) of the 3D printer according to Claim 9, characterized in that the method comprises the steps of:

- providing an object model; - determining a size of the object model and amount of delta robots (20) to be used for printing the object model;

- slicing the object model in predetermined layers;

- splitting each sliced layer into separate sub-layers, wherein each sub-layer is assigned to the delta robot (20) which can print said sub-layer;

- printing the object model using a number of the delta robots (20) to whom said sub-layers are assigned.

11. The method for 3D printing according to Claim 10, characterized in that the step of providing the object model is a step of providing a G-code, which defines the object model to be printed.