EP4448252A1

EP4448252A1 - Apparatus and method for manufacturing a three-dimensional object

Info

Publication number: EP4448252A1
Application number: EP22830931.6A
Authority: EP
Inventors: Márton BARTOS
Original assignee: Duplex 3d GmbH
Current assignee: Duplex 3d GmbH
Priority date: 2021-11-15
Filing date: 2022-10-03
Publication date: 2024-10-23
Also published as: WO2023084262A1; HU231647B1; HUP2100389A1

Abstract

An apparatus for manufacturing a three-dimensional object, comprising • - a material-feed first and second build heads (12a, 12b) arranged opposite each other for building in first and second build volumes (21 a, 21 b), • - a build base unit (10b) with starting build side, and • - a movement mechanism for moving the build base unit (10b) from in-use into out-of-use state, wherein the build base unit (10b) • - in its in-use state is arranged between the first and second build volumes (21 a, 21b) to enable building of a three-dimensional object preform on its starting build side by the first build head (12a) • - in its out-of-use state, has been moved from its in-use state by the help of the movement mechanism to enable building of the three- dimensional object preform by the second build head (12b). Furthermore, a method for manufacturing a three-dimensional object is disclosed. (Fig. 1A)

Description

APPARATUS AND METHOD FOR MANUFACTURING A THREE-DIMENSIONAL OBJECT

TECHNICAL FIELD

The invention relates to an apparatus and a method for manufacturing a three- dimensional object.

BACKGROUND ART

Three-dimensional (3D) printing is a rapidly improving technical field having ever- widening application fields. Research has resulted in several types of 3D printing, determined by the printing base materials and, closely related to that, by the applied printing (building) technologies.

In the developments, the idea of two-sided 3D printing was disclosed for the first time by the present inventor, see in US 2019/0047212 A1 , wherein two-directional printing is elaborated implemented on a liquid light-sensitive synthetic resin applied as a printing base material.

A two-directional printing approach is disclosed also in US 2021/0076502 A1 , which describes building an object on a substrate made of cardboard simultaneously from two directions applying filament deposition.

Two-sided building is applied in certain implementations according to US 2019/0143451 A1 (see Figs. 4A, 5A of the document).

In view of the known approaches, there is a demand for an apparatus and method for manufacturing a three-dimensional object by means of which manufacturing can be done more efficiently compared to existing approaches.

DESCRIPTION OF THE INVENTION

The primary object of the invention is to provide an apparatus and a method for manufacturing a three-dimensional object which are free of the disadvantages of prior art approaches to the greatest possible extent.

A further object of the invention is to provide an apparatus and method realizing twodirectional building for manufacturing a three-dimensional object that apply material- feed build heads, and by means of which manufacturing can be done more efficiently compared to existing approaches.

The objects of the invention can be achieved by the apparatus according to claim 1 and the method according to claim 15. Preferred embodiments of the invention are defined in the dependent claims.

The technological branch of 3D printing that involves plastic fusing is termed the filament extrusion (FDM - Fused Deposition Modelling) method, and in general it can be stated that it is much more widespread than the variant that applies lightsensitive synthetic resin (SLA - stereolithography).

Like the approach of US 2019/0047212 A1 mentioned in the introduction, the invention intends to increase the speed of 3D printing by doubling the layer-build (layer-building) directions, i.e., by two-directional printing. An important difference between these is, however, that in the referenced patent application the base material is light-sensitive synthetic resin that forms the layers after being solidified by light of a specific wavelength, while the base material applied in the present invention is typically either (solid phase) thermoplastic filament material (ABS - acrylonitrile butadiene styrene, PLA - polylactic acid, PETG - polyethylene terephthalate glycol, etc.), or metal filaments of various alloys (in general, materials applicable with a material-feed build head; see also below for the preferably applied materials).

The plastic filament extrusion printers applied in an embodiment of the invention are adapted for processing filaments of various materials, with varying diameter (1.75 or 3 mm), or in certain cases, even granulates. The configuration of the build head varies depending on the form of the base material, but their mode of action is the same: the input base material is passed, by well-controlled feed assistance (support), through a fusing (melting) channel, and after exiting the channel it is deposited as a thin filament (with a diameter of 0.4-1 mm) on the previous layer (the first layer is deposited on an object plate functioning as the base plane).

In another embodiment of the invention, i.e., in the approach applying metal filaments, the configuration of the print head is different from the solution applying plastic filaments in that according to this approach the base material is fused utilising either a high-power laser or high current, according to a principle that is identical to laser additive welding or conventional protection gas arc welding.

Irrespective of the base material (plastic or metal), layer formation by filament deposition is performed in a “shading” manner, wherein first the outlines of each cross-sectional slice are produced, and then the encompassed surface is filled out by lines deposited beside each other in a tightly packed fashion.

According to the above, the invention is a printer applying material-feed build heads, for example a two-directional filament extrusion (FDM) printer.

3D printers can also be differentiated according to their mechanical structure, more particularly their solution for moving the build head relative to the object plate. There is a technical solution, where the build head is moved in the X-Y plane, while moving the object plate in the Z direction. According to another arrangement, the build head is moved in the Z direction, while moving the object table along the X-Y axes.

In the invention, preferably, the so-called “delta type arrangement” (which is based on parallel kinematics) is applied. Here, the object plate is completely static, with three vertical shafts being fixed perpendicular to it, and with linearly guided sliders enabling an arbitrary vertical displacement being arranged on the vertical shafts. The sliders are interconnected via identical-length arms by the build head arranged in the spatial region encompassed by the vertical shafts. By coordinated movement on the three shafts, the build head is able to reach any point of the encompassed spatial region much more quickly than by the conventional, linear movements.

In addition to the delta arrangement, other such 3D printer arrangement is known wherein a fixed object table (build surface) is applied and the build head is moved in the x, y, and z directions (these are for example the printer arrangements of the so-called “core x/y” family, the head movement scheme of which could also be implemented in the invention, but other arrangements based on the same principle can also be devised).

The solution according to the invention therefore describes fused (fused filament deposition) 3D printing utilising preferably thermoplastic plastics or various metal alloys (or other suitable print base materials, see also further below) that is performed simultaneously from two directions and, thanks to the doubled build directions, possesses significant build speed.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below by way of example with reference to the following drawings, where

Figs. 1A-1 B are sectional and spatial drawings illustrating an embodiment of the apparatus according to the invention,

Fig. 1 C is a top view drawing of the embodiment of Figs. 1 A-1 B,

Figs. 2A-2D are sectional detail drawings illustrating the operation of the embodiment of the invention according to Figs. 1A-1 B,

Fig. 3 is a spatial detail drawing illustrating the operation of the embodiment of the invention according to Figs. 1A-1 B,

Figs. 4A-4C illustrate, in spatial drawings, the operation of the clamping arm arrangement and the build base unit in another embodiment of the invention, Figs. 5A-5D illustrate, in top view drawings, the operation of the clamping arm arrangement and the build base unit in yet another embodiment of the invention,

Figs. 6A-6D illustrate, in schematic side view drawings, the operation of the embodiment of Figs. 5A-5D,

Figs. 6E-6G are schematic drawings illustrating the operation of an embodiment similar to the embodiment of Figs. 5A-5D,

Figs. 7A-7D illustrate, in top view drawings, the operation of the clamping arm arrangement and the build base unit in an embodiment of the invention, and Figs. 8A-8D illustrate, in schematic side view drawings, the operation of the embodiment of Figs. 7A-7D.

MODES FOR CARRYING OUT THE INVENTION

The apparatus according to the invention is adapted for manufacturing a three- dimensional object; the apparatus is commonly called a 3D printer (it can also be termed a build/building or print/printing arrangement).

In Figs. 1A-1 B an embodiment of the apparatus according to the invention is illustrated. Fig. 1 A is a sectional drawing and Fig. 1 B is a view drawing. The section shown in Fig. 1A is obtained by intersecting Fig. 1 B with a vertical plane that is perpendicular to the plane of Fig. 1 B.

In Fig. 1 A the build (building) heads 12a, 12b are shown that are arranged opposite each other (they are shown schematically, i.e. , the details of the material feed (material advancing, material feed-out) is not shown) and are situated at both sides of the assembly constituted by a frame element 10a and a build base unit 10b (build base module; configuration and operation of which is described below in relation to Figs. 2A-3), in a first build volume (first building volume) 21 a and a second build volume (second building volume) 21 b, respectively.

In Figs. 1A-1 B the mechanism adapted for moving the build heads 12a, 12b in the illustrated embodiment is shown. It is shown that the build heads 12a, 12b are attached by joint elements to support rod elements 16 (stick elements); in total, six support rod elements 16 are applied for retaining each of the respective build heads 12a, 12b in the appropriate position, and for moving them (see Fig. 1 B showing all six of the support rod elements 16; also see Fig. 3 for details of the jointed (articulated) connection of the support rod elements 16).

The housing structure 15 (by other name, support structure for supporting the build heads and the build base unit) comprises the upper and bottom end elements 18a, 18b, and the three column elements 20 adapted for interconnecting them. In Fig. 1 C, the upper end element 18a is illustrated in top view; in this view the connection points of the column elements 20 can be seen. The end elements 18a and 18b have similar configuration; as illustrated in Fig. 1 C, in the illustrated exemplary configuration they have a basically triangular shape with outwardly curved sides. The column elements 20 are attached to the corners of this triangle, i.e., according to the illustrated preferred configuration the column elements 20 are situated at the comers of a regular triangle, so the distances between adjacent column elements 20 are identical. The view according to Fig. 1 A is obtained by taking a section of Fig. 1 B as indicated in Fig. 1 C.

According to the illustrated configuration, the movement of the build heads 12a, 12b is implemented such that each build head 12a, 12b is attached to a respective sliding member 14 (sled member) by a pair of support rod elements 16, the sliding members being movable along the corresponding column element 20. This movement is as if the sliding members 14 were slid along the column elements 20. The vertical movement - i.e. , according to general convention, the Z-direction movement - of the sliding members 14 - and thus also of the build heads 12a, 12b - is preferably made a constrained (forced) movement by applying a linear path - on the column - in conjunction with a carriage - which is the sliding member 14 itself -, (i.e., they undergo a constrained movement assisted by these components), and for example can be driven by a ribbed belt attached to them that is driven by means of tensioning wheels at the bottom and, at the top, a strap disc attached to the shaft of a stepper motor (the latter components can also be arranged in the end elements 18a, 18b and the support elements 26, see Fig. 1 B, where a support element 26 can be seen at each of the four corners of this middle portion).

As it is illustrated by the connections shown on the right side of Fig. 1A, the support rod elements 16 are also connected to the sliding members 14 by means of joint elements (see also in Fig. 1 B the oppositely situated sliding member 14 on the middle column element 20).

It is easy to see that by causing the sliding members 14 to slide along the column elements 20 - that is, in case all sliding members 14 are displaced in the same direction by the same amount - the height (i.e., in the drawing, the vertical position) at which the build heads 12a, 12b are situated at can be changed.

Besides that, the arrangements allows that the build heads 12a, 12b can also be moved sideways (i.e., conventionally, in the X-Y direction) in case the sliding members 14 are elevated to different heights (i.e., in case they are arranged at different distances from the frame element 10a and the build base unit 10b). An example for such a movement is moving the sliding member 14 situated on the right of Fig. 1 B upwards along the column element 20 while sliding the other two sliding members downwards; this can result in shifting the build head 12a to the right while keeping its height constant. Accordingly, a first build volume 21 a is accessible (can be covered, passable) by the movement of first build head 12a, and a second build volume 21 b is accessible by the movement of the second build head 12b such that the build heads 12a, 12b are kept horizontal, i.e., parallel to the frame element 10a and to the build base unit 10b in the in-use state thereof (this position corresponds to the printing performed by means of the build heads: utilising them, the three- dimensional object can be built in the entire build volumes 21 a, 21 b).

The frame element 10a is attached to the column elements 20, expediently such that it is arranged horizontally too if the first end element 18b is arranged on a horizontal platform (it can also be fixedly attached in case the frame element 10a is arranged in an internally remaining manner, but alternatively, if a removable, replaceable frame element 10a is applied, it can also be inserted into the apparatus

- i.e. , in some manner placed and retained therein).

The build base unit 10b is adapted for supporting a three-dimensional object and for enabling building of the object from the other direction applying the build head 12b (since with the movement thereof the support is removed, besides enabling to build by means of the second build head, it of course also does not affect continued building by means of the first build head). Accordingly, the three-dimensional object is provided with an orientation by the build base unit. The build base unit 10b is connected to the column elements 20 via a shaft 17 (see Fig. 2C).

In an illustrative example, dimensions are specified below for the apparatus according to the invention based on Fig. 1 A. In the example, in the view of the figure

- the total height of the apparatus shown in Fig. 1A is 2200 mm, the total width thereof is 900 mm, and the height of the end elements 18a, 18b is 82 mm;

- the width of the build heads is 120 mm (comparison with Fig. 3 shows that this is an appropriate characteristic dimension for characterising the build head, in the case of the substantially hexagonal build heads this corresponds to the distance between two opposite sides);

- the length of the support rod elements 16 between the joints is 474 mm;

- the height distance between the connection points of the joints of the support rod elements 16 (provided that the build heads are oriented horizontally) is 400 mm;

- the edge of the build heads facing the assembly formed by the frame element 10a and the build base unit 10b in the in-use state can be brought at a distance of 0-500 from the proximate sides of the assembly;

- the thickness of the assembly as measured in the height direction is 98 mm, while the thickness of the frame element 10a and the build base unit 10b measured also in this direction at the edges thereof is 49-49 mm. - the useful build diameter of the starting (initial) build side of the build base unit is (see the diameter of the elevated (lifted, outstanding) surface region 11 in Fig. 3) 400 mm;

- the width of the column element 20 is 40 mm (in the view according to Fig. 1 A, the column element 20 on the left).

Furthermore, in the example having the above listed dimensions, a distance corresponding to the layer thickness specified in the processing program (0.05-0.4 mm) is always maintained between the nozzle of the build head (i.e. , the point of the head that emits the build material; in the case of filament deposition, it is preferably performed by a nozzle, or, in a more general term, an dispensing (out-dosing) end, the material feed can also be carried out through the dispensing end) and the print surface. Therefore, the layer deposited during the build process typically has a thickness of 0.05-0.4 mm.

The operation of the frame element 10a and the build base unit 10b, that is, the steps of printing - i.e., of building a three-dimensional object - are illustrated by Figs. 2A-2D, from the start of the printing up to the stage when already both build heads 12a, 12b works for manufacturing the three-dimensional object.

In Fig. 2A, the starting position (initial state) is illustrated, wherein the build heads 12a, 12b are at a certain distance from the frame element 10a and the build base unit 10b. These two components - being differentiable by the direction of the hatching - abut against each other (the build base unit 10b is folded up onto the first frame element 10a).

In Fig. 2A, because the manufacturing of the three-dimensional object has not yet started, there can be observed a starting build side 19 that expands to (covers) the top surface of the build base unit 10b (for more details related to building on the build side 19 and the preferred tempering, see below).

Figs. 2A-2D show a magnified view of the middle portion of the apparatus that comprises the frame element 10a and the build base unit 10b, so in the figures there can be seen the details of the attachment of these components to the column element 20. On the left only a small portion of the column element 20 is visible, it can however be seen (cf. Fig. 2D) that the frame element 10a is pushed against an end position element 22 (the build base unit 10b is also arranged fitting to the end position element 22, however, it can expediently be folded downward from here, i.e., it is not pushed in but remains in the apparatus, see also further below).

The frame element 10a can preferably be removed from the apparatus, in which case it can be pulled out therefrom by moving or pulling it further from the end position element 22 that is situated opposite the open (from the oppositely situated column element 20; cf. Fig. 3 that illustrates in a spatial-view drawing how the column elements 20 surround the assembly constituted by the frame element 10a and the build base unit 10b, and how the components thereof are situated in the spatial region encompassed by the three column elements 20).

In Fig. 2B it is illustrated how the build head 12a being at the top is brought nearer to the build base unit 10b such that it starts building the three-dimensional object on the build side 19 (this latter constitutes a first build step S100). A three-dimensional object preform 25’ (it is called a preform because it is an initial status - a preform status - of a three-dimensional object to be manufactured) can be observed in Fig. 2B that also illustrates that in this embodiment the build (build process) is performed in a spatial region encompassed by the frame element 10a, and the three- dimensional object preform 25’ spans the entire cross-section of this spatial region (in this sectional view, the structure of the three-dimensional object preform 25’ cannot be seen, only the layers thereof; this schematic depiction was not intended to illustrate the structure of the three-dimensional object preform 25’), i.e., it is situated (lies) on the flat top portion of the elevated surface region 11 of the build base unit 10b, and also reaches (extends) onto the inside rim 13 encompassing the elevated surface region 11 , that is, the layers of the three-dimensional object preform 25’ are on the inside rim 13.

The elevated surface region 11 is a flat plateau portion that is elevated with respect to the rest of the surface of the build base unit 10b that faces the frame element 10a; it preferably has a uniform height forming a flat surface, such that printing can be performed on a flat surface. As shown in Figs. 2A-3, the uniform height is formed such that this portion that extends higher relative to the other surface regions of the build base unit 10b protrudes at a uniform height when it is folded up onto the frame element 10a.

This “seating” can be better observed in Fig. 2C illustrating that after building a certain number of layers, the build head 12a is removed from the three-dimensional object preform 25’ (which three-dimensional object preform 25’, like the other three- dimensional object preform 25” is a “fragment”, i.e., an initial portion of the three- dimensional object to be built), and then, by opening the build base unit 10b downwards (i.e., by folding it down, in this embodiment this constitutes a movement (moving) step S110) the three-dimensional object preform 25’ is separated (detached) from the elevated surface region 11.

The purpose of the separation (detachment) is to allow the operation illustrated in Fig. 2D to be carried out, i.e., opening downwards the build base unit 10b (it must release the three-dimensional object preform 25’ so as not to damage it), which in turn makes it possible that the three-dimensional object preform 25’ can be built also from below applying the build head 12b, so that it can be appropriately approached also by the build head 12b in a manner illustrated in Fig. 2D. Therefore, both build heads 12a, 12b are able to perform building, and accordingly, Fig. 2D illustrates a main build step S120 in this embodiment.

In Fig. 2C a shaft 17 for opening downwards is marked indicating around it the direction in which the build base unit 10b is rotated to open it downwards. The shaft 17 is expediently arranged such that the build base unit 10b of the apparatus can be folded down separately from the frame element 10a (cf. Fig. 3 showing a shaft support element in the centre of a fixing element 27, through which the shaft is connected to the column elements 20, i.e., enables rotation with respect to the apparatus). The frame element 10a and the build base unit 10b are expediently not connected to each other but are arranged beside each other in an initial state with appropriate arrangement.

In Fig. 2D, the build base unit 10b is folded down into a vertical state, enabling the build head 12b to access the yet built three-dimensional object preform 25’ (the build head 12b must be retracted while the build base unit 10b is folded down to provide sufficient room for the build base unit 10b). In a particularly preferable manner, opening downwards of the build base unit 10b enables that the three-dimensional object preform 25’ built by the build head 12a from above can also be built utilising the build head 12b from below. In Fig. 2D it is illustrated that the three-dimensional object preform 25” depicted therein is already being built both from above and from below.

In contrast to Figs. 2A-2D, in Fig. 3 the frame element 10a and the build base unit 10b are shown in a spatial view, not in a sectional view. For the sake of illustration, in Fig. 3 the build base unit 10b is opened downwards from the frame element 10a such that a three-dimensional object is not being built (is not arranged) in the spatial region encompassed by the frame element 10b (so that the opened-downwards build base unit 10b can be clearly seen). Corresponding to the opened-downwards state there can be observed the inside rim 13 (inward protruding rim) along the inside circumference of the frame element 10a.

In Fig. 3 the build head 12a can be seen; the bottom build head 12b is largely obstructed from view, only the support rod elements 16 thereof can be observed. In Fig. 3, the build head 12b is in theoretically situated in a position wherein the build base unit 10b is opened down on the build head 12b. This situation, however, cannot occur in reality, because in such a case the build head 12b must be retracted back such that it is not damaged by the build base unit 10b being opened downwards. According to the illustrated state, one of the sliding members 14 and the jointed connections thereto of the support rod elements 16 can be seen under the build base unit 10b.

As it was mentioned above, in the spatial view of Fig. 3, the manner of connection of the support rod elements 16 to the build head 12a can be better observed; it can be seen that three pairs of support rod elements 16 are connected from three sides.

In the above-described opening arrangement and the corresponding method (printing process), particularly preferably plastic filament fusing (melting) is applied (or of such material the separation of which can be performed in a manner similar to plastic), and the embodiments Illustrated in Figs. 4A-6G are preferably based on this principle, while the arrangement and method of the embodiment illustrated in Figs. 7A-8D is preferably based on metal filament fusing/melting (or of other materials for which separation is expediently not applied). The build base materials that can be expediently applied are also described below.

In summary, the following can be set forth (in certain cases, optionally) regarding the embodiment of the invention described above in relation to Figs. 1A-3.

In the case of the illustrated arrangement, two build heads (together with the corresponding arms, i.e., the support rod elements 16 and sliders, i.e. sliding members 14) are arranged on the vertical shafts (on the column elements 20) such that the ends (sides) of the build heads adapted to deposit filaments face each other. In this embodiment, an intermediate element (intermediary element) consisting of two parts (two halves; the frame element 10a and the build base unit 10b; in this embodiment this assembly is termed an “intermediate element”) is situated in a perpendicular partitioning (bisector, halving) plane of the vertical shafts (i.e., it is expediently arranged at the centre).

The upper portion of the intermediate element is the object ring (frame element 10a), while its bottom portion is the object plate (build base unit 10b). Preferably, the build ring can be moved - parallel to the partitioning plane - into and out from the spatial region encompassed by the vertical shafts by means of a rail mechanism, such that during the insertion an appropriate position is provided by a bumper end stand (end position element 22), while the build ring can be freely removed from the apparatus (as it will be touched upon, the build ring or frame element can also be of internally remaining arrangement). The object plate is adapted to be rotated - in a downwards-opening manner - by 90 degrees with respect to the partitioning plane (see Fig. 2D) such that the axis of rotation thereof coincides with an imaginary cord tensioned between the two adjacent vertical shafts.

The upper plane of the object plate (that is, the upper side of the build base unit 10b according to the figure, extending into the spatial region encompassed by the frame element 10a) is preferably an anti-adhesion (adhesion exempted) surface. The object ring and the object plate (i.e., the frame element 10a and the build base unit 10b) can preferably be heated applying a heating cartridge; their momentary temperature can be measured. As it can be seen below in the discussion on the steps of the printing process and was also mentioned above, it is preferably necessary to heat also the object ring in addition to the object plate since in this embodiment it is also built on during the printing, such that when the object plate (i.e. , the build base unit 10b) is opened downwards, the already built portion can be retained in place, and build can be continued from below.

In the illustrated embodiment, the printing process applicable with the opening arrangement preferably has the following steps.

1 . Both build heads are at a safe vertical distance (initial position) from the horizontal partitioning plane (and thus from the assembly of the frame element 10a and the build base unit 10b arranged there).

2. In the inserted end position, that is, in the position where it is fully pushed inside to place (see the state shown in Fig. 2A) of the object ring (first frame element 10a), the object plate (build base unit 10b) is situated parallel to the horizontal partitioning plane, in a closed state (the build base unit 10b is folded up against the first frame element 10a from below).

3. The object ring and object plate are both heated up (to a temperature of 60-120 °C depending on the base material).

4. After reaching the desired temperature, the upper head starts filament deposition on the top surface of the object plate within the inside diameter of the object ring.

5. After reaching the thickness of the material of the object ring (0.8-2 mm), layerbuild is continued along a path also covering a more outside-lying diameter of the ring (more precisely, as illustrated in Figs. 2A-2D, when this level is reached, on the inside portion of the frame element 10a, on the top surface of the inside rim 13 according to the figure).

6. When a predefined initial layer thickness is achieved (that is, when a predetermined minimum material thickness of the built three-dimensional object is achieved), the upper head is stopped, and is moved further away from the built three-dimensional object.

7. Turning off the tempering results in a decrease in the temperature of the object plate, as a result of which the initial layer already manufactured can be easily separated from the anti-adhesion surface. 8. Being separated from the built three-dimensional object, the object piate (build base unit 10b) is opened downwards into a position that is expediently perpendicular to the partitioning plane (the perpendicular position is preferable because it does not hinder the movement of the bottom build head).

9. Heating of the build ring is switched on again.

10. Layer-build (layer-building) is carried on by means of the upper head, while the bottom build head also starts filament deposition (for upward feed or extrusion a slightly higher torque is required in the head unit for material or filament forwarding with respect to downwards-directed deposition).

11. The two build heads operate simultaneously until the desired geometry of the built three-dimensional object is completed.

12. In the last step, the build heads approach their bottom and upper end positions, and the object ring comprising the print geometry (the built three-dimensional object) can be pulled from the spatial region encompassed by the vertical shafts (column elements 20) in a direction parallel to the horizontal partitioning plane.

In accordance with the illustrated embodiments, i.e. also with the embodiments described above, the apparatus according to the invention comprises a materialfeed first build head (see first build head 12a, 54a, 74a, it can also be called a material dispense (type) build head) for building in a first build volume (see for example a first build volume 21 a in Fig. 1A), and a material-feed second build head (see second build head 12b, 54b, 74b) for building in a second build volume (see for example a second build volume 21 b in Fig. 1A; instead of the term “volume”, the term “region” can also be applied), (the first build head and the second build head are) arranged opposite each other.

According to the invention, material-feed build heads (build heads being materialfeed type, adapted for material feeding, being material-feed applying, being material-feeding) are applied. These build heads, therefore, are such build heads that perform building by dispensing (feeding) the base material from some kind of (fusing) container connected to the head. A material-feed build head can preferably be an extrusion build head, particularly a filament extrusion build head (materials of filament or granulate form can equally be fed). The building (printing) base material may be any material that can be dispensed by feed (these materials are herein collectively referred to as three-dimensional build or print base materials). Expediently applied build base materials are the following:

- thermoplastic plastics in filament form;

- thermoplastic plastics in granulate form;

- a combination of thermoplastic or thermosetting polymers and shredded fibre reinforcement (glass fibre, carbon fibre, kevlar; thermoplastic and thermosetting materials require tempering of different timing or amount - if it is necessary at all the tempering scheme utilised in this description, for example in the case of the embodiment of Figs. 1A-3, or the tempering scheme to be set forth below is to be applied with thermoplastic base materials; thermosetting plastics are cross-linked at a different temperature, or in many cases applying an appropriate light source - see photopolymers accordingly, the implemented build method can be adapted to the chosen build base material);

- a combination of thermoplastic or thermosetting polymers and continuous fibre reinforcement (glass fibre, carbon fibre, kevlar);

- weldable metal filament materials (non-alloyed and alloyed steels, aluminium, copper, titanium, etc., such materials are also applied for laser additive welding);

- mixtures of the powdered forms of the above listed metals and various matrix materials (thermoplastic or thermosetting plastics; water, etc.);

- ceramics in paste form;

- biocompatible (tissue friendly) hydrogels, so-called bio-inks.

It can be seen that the above discussion refers for example to plastics and also to metals, the particular applicability of the latter being emphasised in certain embodiments, thus, the metal materials in the embodiment of Figs. 7A-8D (in this embodiment other such materials can also be applied that are not particularly suited for separation; the other materials can be applied with further embodiments).

The apparatus according to the invention further comprises

- a build base unit (see in Fig. 1A the build base portion 10b, and for example in Figs. 5A and 6A a build base unit 52 and for example in Figs. 7A and 8A a build base unit 72; in Figs. 4A-4C the build base portions 32a-32c that are the main components of the build base unit can be seen) having a starting build side (see build sides 19, 39, 59, 79 utilised with the above-mentioned build base units 10b, 52, 72), and

- a movement mechanism for moving the build base unit from an in-use state into an out-of-use state, wherein the build base unit

- is arranged in its in-use state between the first build volume and the second build volume to enable building of a three-dimensional object preform (see for example the preforms 25’, 25”, 35, 55) on its starting build side by means of the first build head,

- in its out-of-use state, has been moved (is moved; in the out-of-use state it has been moved) from its in-use state by the help of (by means of, using) the movement mechanism to enable building of the three-dimensional object preform by means of the second build head.

According to the invention, it therefore holds true that the first build head and the second build head are utilised for building the same three-dimensional object in a materially continuous manner (compared to known technical solutions this is regarded as improved efficiency), because building on one side is started by means of the first build head (producing a three-dimensional object preform on the starting build side), then, by moving (moving into, moving thereto, moving over, moving across) the build base unit from the in-use state (in-use status, in-use position, use state) into the out-of-use state (out-of-use status, out-of-use position, non-use state) it is made possible for the second build head to (further) build - simultaneously with the first build head - the three-dimensional object preform produced earlier, thereby producing the desired three-dimensional object from the preform.

In addition to that, the above-described initial arrangement of the build base unit in the in-use state also entails that the build operation is started at the chosen side - typically from above - by means of the first build head, while the build base unit specifically blocks the possibility that the second build head builds in the in-use state of the build base unit.

The movement mechanism (moving mechanism) and the movement (movement into, into-movement, movement thereto, movement over, over-movement, movement across, across-movement) done with it - i.e. , the movement (“movement into”) step is also defined (see also below) - is implemented in the embodiment of Figs. 1 A-1 B by connecting to each other with the shaft (i.e. joint), by means of which the build base unit 10a can be moved from the folded in-use state (in which the build base unit 10b is folded up onto the frame element 10a such that it covers the opening - i.e., the interconnecting space part - thereof) into the out-of-use state, wherein the first build base unit 10b is folded down, making it possible to build the three-dimensional object preform (which was previously supported from below and built from above) from below applying the second build head. This movement ("movement into”) is possible because the three-dimensional object preform is built on the frame element 10a.

In the embodiment comprising the iris arrangement illustrated in Figs. 4A-4C this is implemented in the following manner. In the in-use state, the iris (i.e. build base portions 32a-32c) is closed so as to provide support for the three-dimensional object preform. The movement ("movement into”) from this position into the out-of-use state is implemented by opening apart the build base portions 32a-32c, freeing up the bottom face of the three-dimensional object preform for building by means of the second build head. In this embodiment, the movement mechanism is implemented by moving arms 38a-38c connecting the build base portions 32a-32c to a frame element 31. To enable the movement ("movement into”), the three-dimensional object preform is held utilising clamping arms 36a-36c (arms for clamping (grabbing, gripping)).

Like in the previous embodiment, in the embodiment of Figs. 5A-6D also apart- opening is applied, but this is applied as the initial step of removing support that is aimed at separating the three-dimensional object preform 55. The movement ("movement into”) process and the manner of enabling a second build head 54b to engage in printing (building) can be seen in Figs. 6A-6D that illustrate that in the movement (“movement into”) step the build base unit 52 originally positioned under the three-dimensional object preform 55 is moved out from under the three- dimensional object preform 55 (in Fig. 6D, its rotation into a vertical position is illustrated) providing access to the three-dimensional object preform 55 clamped in a clamping arm arrangement 56 (coronal lock (clamp), wreath/wreath-shaped lock, corona/corona-shaped lock). In Figs. 6E-6G, separation is performed in a different way (see below), however, the movement (“movement into”) step of a build base unit 62 is expediently also carried out in the manner illustrated in Figs. 6A-6D.

The movement ("movement into”) step is performed in an identical manner also in the embodiment illustrated in Figs. 7A-8D, wherein a build base unit 72 having an undivided configuration is applied.

In these latter embodiments (the embodiments of Figs. 5A-8D) the build base unit comprises a movement support element (see movement support element 64 below) enabling displacement of the build base portions and arranged opposite the starting build side thereof (with the starting build side of the build base unit is configured by means of mutually displaceable build base portions).

Furthermore, the movement mechanism (which is not shown in the figures) can be preferably implemented such that the movement mechanism is configured by means of movement rails and one or more (for example, expediently two) guide elements adapted to be guided by each of the movement rails (this can mean that in or on the rails) for moving the build base unit from its in-use state into its out-of- use state, wherein each movement rail and the corresponding one or more guide element are arranged in the apparatus and, in a manner fitting thereto, on the movement support element of the build base unit, respectively.

In an embodiment of the method corresponding to this embodiment, in the movement ("movement into”) step, the build base unit is moved from its in-use state into its out-of-use state by guiding the guide elements along the movement rails.

In the illustrated case, the movement rails and the guide elements are arranged such that the build base units 52, 62, 72 can undergo displacement along the illustrated path, i.e. , starting from under the three-dimensional object preform 55 and rotated by approximately 90° they can assume a position at the side (i.e., it rotates such that in the out-of-use state it is oriented transversely with respect to the in-use state). To achieve that, the movement rails are expediently arranged on the housing structure at both sides of the build base unit 52, 62, 72, and the guide elements are arranged on both sides of the build base unit 52, 62, 72 (in Figs. 6A-6D and 8A-8D these are the sides facing towards and out form the plane of the figure, corresponding to the movement of the build base unit 52, 62, 72).

The movement rails and the guide element can also be arranged in a different manner, for example such that the rails are arranged on the build base unit 52, 62, 72 and the guide elements are arranged on the housing structure, or one can be applied on one side, and the other on the other side.

Movement by means of the movement mechanism can preferably be automated (for example, the downward opening in the embodiment of Figs. 1A-1 B and the apart opening in the embodiment of Figs. 4A-4C, or the displacement along the rail in the embodiments of Figs. 5A-8D are performed in an automated manner), but manual operation is also conceivable (this requires a housing, for example the housing structure 15, that allows to reach into the apparatus from outside). That is why it is called a “movement mechanism”, refer to that the movement is performed by the help of these constructional details.

In an embodiment of the invention, a frame element is arranged in an internally remaining manner or can be arranged between the first build volume and the second build volume - i.e., it can be considered that between the first and second build heads - (in other words, it can be placed or introduced thereto, i.e., in an opposite direction it can also be removed, pulled out therefrom, and preferably the apparatus has an insertion opening adapted for introducing the frame element therein to arrange it), wherein the frame element is configured to encompass (encircle) an interconnecting space part (connecting space part; see for example a frame element 10a in Fig. 1A, and a frame element 31 in Figs. 4A-4C).

The phrase “can be arranged between them” can be rephrased as “it is arranged during the operation (running) of the apparatus” (when a three-dimensional object is being built utilising the apparatus), i.e., when the apparatus is operated and the build base unit is in the in-use state and in the out-of-use state, then it is obviously arranged therein.

The build volumes are therefore in this case bounded by the frame element (it is inserted therebetween), and the build base unit in its in-use state is also arranged here (temporarily). Their position can be taken into account for programming the movements of the build head.

In its in-use state, the build base unit is situated at the boundary of the first build volume because building is performed at the starting build side thereof, and the build head only moves in a direction away from it - this is what must be taken into account of the build base unit for planning the movements of the first build head.

When the second build head is utilised, the build base unit is moved into its out-of- use state, and at the same time the second build head starts printing from the original position of the starting build side of the build base unit, i.e. , at the surface already completed thereon. Besides that, the frame element must also be taken into account when moving both heads.

Accordingly, the frame element is situated between the build volumes (i.e., at the junction thereof, the frame element borders them) and it is determined by the frame element and by the components arranged over there how much of the build volumes can be taken up by them (the region where the frame element is situated is obviously not part of either one of the build volumes, it is a restriction on moving the build heads - for example at a programming level - that the build heads cannot be moved there so as not to collide with the frame element). The frame element can also be considered to be arranged in an internally remaining manner in a receiving spatial region or it can be arranged therein; the frame element is however arranged in this receiving region such that at least one of the build heads is engaged in building in the interconnecting space part encompassed by it (in the embodiments of Figs. 1A- 1 B both build heads, in the embodiment of Figs. 4A-4C the second build head; this is dependent on the relative position of the starting build side and the frame element).

The planes assignable to the frame element and the starting build side are typically parallel to each other (the plane assignable to the starting build side preferably fits on the side itself). A plane can also be assigned to the frame element, and planes parallel to the plane of the frame element can be defined; in certain cases, more than one parallel planes can be assigned to the frame element - the normal of the end faces of the region encompassed by the frame element are also perpendicular to the plane of the frame element - however, this plane can be defined on the flat faces thereof or in the frame element, the planes parallel thereto are uniquely determined, i.e., this defines the direction of the plane of the starting build side.

To sum up the above, the frame element is positioned (situated) between the build volumes such that at least one of them extends into the interconnecting space part encompassed by it (of course, as it is not a closed region and accordingly the corresponding build head can also extend therein), and these are separated by the location that the starting build side the build base unit assumes in the in-use state. The frame element - being flat according to its name and defining a plane by its flat shape - is arranged between the two build volumes also in a sense that one of the build volumes is situated along one of the flat sides of the frame element, while the other build volume is situated along the other flat side thereof.

The frame element 10a can expediently be put in its place by pushing (inserting) it in above the build base unit 10b; this can be apprehended by looking at Fig. 3.

The build heads are therefore preferably arranged opposite each other. Because they are displaceable in a direction parallel to the frame element and to the starting build surface, this is obviously included in the mutually facing arrangement, which can also be called an opposite arrangement.

As a result of this, the build volumes are of course also arranged opposite each other. Accordingly, the requirements laid down for the build volumes can also be applicable for the build heads. This is also related to the fact that the build heads are able to access (cover) by their movement the corresponding build volume. Each build volume therefore extends (from both sides) as far as the starting build side.

In the embodiment of Figs. 4A-4C, only the frame element 31 and the adjoining components are shown. In this embodiment, the frame element 31 is arranged in the apparatus in an internally remaining manner because for example the build base portions 32a-32c are also attached to it.

The frame element is not shown in Figs. 5A-8D, however, the clamping arm arrangements 56 and 76 must be placed (arranged) on a frame element, so a respective receiving space part corresponding to the frame element can be identified (confined) e.g. in Figs. 6A-6D and 8A-8D (and also in Figs. 4A-4C).

It is typically necessary to include the frame element in the invention because it is the interconnecting space part encompassed by it that provides material continuity between building by means of the first build head and the second build head, in other words, the apparatus is able to “print through” the spatial region encompassed by the frame element. The built three-dimensional object will preferably be attached to the frame element (for example it will be bult on its inside rim, or by means of clamping arms). The frame element can thus also be termed a ring element.

The apparatus preferably has a housing structure (see a housing structure 15 in Figs. 1A-1 B). The housing structure includes all housing-related components of the apparatus, i.e. , in addition to the support structure-like arrangement illustrated in Figs. 1A-1 B for example a cover or casing optionally applicable on the apparatus. The components of the apparatus (for example, certain components of the movement mechanism and - in a movable manner - the build base unit) are preferably attached to the housing structure. The housing structure preferably defines the location of the frame element, i.e., where the frame element is arranged or where it can be inserted from outside.

In case the apparatus has a housing structure, the build heads are movably attached thereto. From the definition of the build heads given above (they are adapted for building in a build volume) it follows that the build heads are movable, because they can operate in the entire build volume.

The movement mechanism that enables to build in a materially continuous manner - i.e., building the same three-dimensional object preform from two directions, utilising the same material - is not disclosed in prior art documents.

In the document that can be identified as the closest approach from the listed above, US 2021/0076502 A1 , the base on which filament deposition printing is carried out is touched upon rather succinctly. The cardboard-based substrate mentioned in the document can be interpreted as such a base - however, the movement mechanism applicable according to the present invention cannot be learned from the document. Cannot be learned therefrom the movement (“movement into”) of the build base portion, which illustrated based on the embodiments means that the build base portion is taken from its in-use state into its out-of-use state by moving it, for example by folding down or by opening apart it (in the embodiment of Figs. 4A-4C, the build base portions 32a-32c constitute parts of the build base unit, thereby forming the starting build side, said portions being moved from the in-use state into the out-of- use state), or by driving it along rails optionally followed by dropping it downwards. It is important to note that the movement (“movement into”) between the in-use and out-of-use states affects the two states of the build base unit, because during the operation of the apparatus a switch between these states is carried out. It is, for example, therefore not related to how the build base unit can be dismounted or removed from the apparatus.

Preferably, the movement (“movement into”, movement operation) can be expressed in such that the build base unit is moved ("moved into”; or displaced) in (inside) the apparatus from the in-use state into the out-of-use state applying the movement mechanism. It is preferable to keep the build base in the apparatus unit during the operation (i.e. , in a protected status) also because the surface of the build base unit is preferably a precisely formed (machined), optionally also provided with a coating (in many cases, sensitive) surface, so protecting this surface from external effects in (inside) the apparatus constitutes an advantage with regard to the utilisation (irrespective whether the apparatus is closed or has a housing structure, as the requirement of no external user effects can be fulfilled in these cases).

Movement (displacement) in (inside) the apparatus preferably means that in the out- of-use state the structural or inclusive relationship between the apparatus and the build base unit is maintained. In the illustrated embodiments, this manifests itself such that the build base unit remains on the shaft in the folded-down state, when it is opened apart, it remains connected to other components by means of the moving arms and the auxiliary shaft (in that embodiment, the frame element is preferably arranged in an internally remaining manner), as well as in the rail-guided arrangement the relationship is provided by the guiding action, or if it is dropped downward at the end of the rails, then it is not dropped out from the apparatus but is stored in a suitable storage portion thereof, i.e. an inclusive relationship is maintained even in this case.

As it was touched upon above, preferably a frame element is also applied, which are either arranged in an internally remaining manner, or can be inserted into the apparatus (for example like a drawer, as some kind of print cartridge). Accordingly, the apparatus according to the invention preferably employs two separate printing assistance means, i.e., in addition to the build base unit it also has a frame element.

None the above-described additional features (movement ("movement into”), movement inside the apparatus, the application of a separate build base unit and frame element that can expediently be operated separately) can be learned either from US 2021/0076502 A1 or any other prior art approach.

Some embodiments of the invention relate to a method for manufacturing a three- dimensional object. In course of the method according to the invention (the steps below are in fitting with the features defined in relation to the structural components of the apparatus according to the invention, so reference is also made to the description thereof)

- building, in a first build (building) step (see operational step S100 in fig. 2B, operational step S200 in Fig. 6A, operational step S260 in Fig. 8C; this step can also be called a pre-, an initial or starting build step), a three-dimensional object preform on a starting build side of a build base unit being in an in-use state by means of a first build head of oppositely arranged material-feed first build head for building in a first build volume and material-feed second build head for building in a second build volume (the first build head and the second build head are arranged opposite each other; this is of course allowed by arranging the starting build side such that it faces the first build volume), wherein, in the in-use state, the build base unit is arranged between the first build volume 21 a and the second build volume 21 b,

- in a movement step (see operational step S110 in Fig. 2C, operational step S230 in Fig. 6D, and operational step S270 in Fig. 8D) after the first build step, the build base unit is moved by the movement mechanism from its in-use state into its out-of-use state, wherein, in its out-of-use state, the build base unit has been moved from its in-use state by means of the movement mechanism to enable building of the three-dimensional object preform by means of the second build head, and

- in a main build step (see operational step S120 in Fig. 2D) after the movement step, building of the three-dimensional object preform is continued by means of the first build head, and is started by means of the second build head.

Thus, the three main steps of the method according to the invention are, according to the above,

- the first build step, wherein the three-dimensional object preform is built by means of the first build head,

- the movement step, wherein building by means of the second build head is made possible by a movement ("movement into”) by means of the movement mechanism, and

- the main build step, wherein the three-dimensional object preform is built by both the first build head and the second build head, i.e. in the main stage of the build, by building on the preform, the three-dimensional object to be built (printed) is manufactured.

Preferably, in an embodiment of the method corresponding to an above-mentioned embodiment of the apparatus, a frame element arranged in an internally remaining manner is available between the first build volume and the second build volume or the frame element is arranged therebetween, wherein the frame element is configured to encompass an interconnecting space part.

It is noted that, like in the case of the known (single-head) 3D printers, in the apparatus and method according to the invention printing is also performed in such a way that the build heads perform the build according to a predetermined program, typically building the three-dimensional object in a layer-by-layer fashion. The three- dimensional object is therefore realised based on being programmed, taking into consideration in this case the build process according to the above steps, as well as the realisation by means of two build heads (i.e., that in which stage and by means of which build head the particular portions of the three-dimensional object are to be produced, and also that where to have the location of portion of the object, the realisation of which it is started or which is to be built into the three-dimensional object as a remaining (permanent) object). Such an implementation is of course also conceivable in which the three-dimensional object is designed to have such a portion - for example, a portion originally located at the frame element - that would later be removed from the three-dimensional object in order to obtain the valuable part thereof (for example, designing a retaining ring into it).

Furthermore, in the embodiment of Fig. 1A-1 B, in the apparatus according to the invention

- the movement mechanism is configured by means of a shaft 17 for opening downwards passed through (led through, extending through) the build base unit 10b (it is secured into the apparatus, for example in the case according to Figs. 1A-1 B to the housing structure 15, more particularly to two adjacent column elements 20) and enable to open it downwards, and

- the build base unit 10b is arranged along the frame element 10a in the in-use state (i.e., folded up to it, preferably protruding into it, while along the frame portion these abut against each other) and is opened downwards with respect to the frame element 10a opposite the first build volume 21 a in the out-of-use state.

In an embodiment of the method according to the invention corresponding to the present embodiment of the apparatus, in the movement (“movement into”) step, the build base unit 10b is moved from its in-use state into its out-of-use state by opening it downwards. It is formulated that the build base unit 10b open downwards opposite the first build volume 21 a. This can also be termed that the build base unit 10b opens downwards towards the second build volume 21 b, however, this should be specified that expediently the build base unit 10b is situated after being opened downwards such that it is brought out from the second build volume 21 b, and thus it does not hinder the operation of the second build head 12b (i.e., building with that), since the build volume is that volume that can be accessed (covered) by the movement of the given build head, i.e., wherein the given build head can be applied for building.

In the present embodiment, the build base unit 10b preferably has an elevated surface region 11 fitting, in the in-use state, into the interconnecting space part encompassed by the frame element 10a (which can be inserted into the encompassed space part by rotating the build base unit 10b about the shaft 17 for opening downwards). Also, the frame element 10a preferably has a circumferential inside rim (flange) 13 extending from its inside circumference, and the elevated surface region 11 fits into the space part encompassed by the inside rim 13.

Particularly preferably, a first height of the elevated region protruding into the frame element (that is, the height of the extend protrusion thereof) when fitted therein is smaller than or equal to a distance between a side of the inside rim 13 facing the first build volume 21 a and a surface of the frame element 10a facing the second build volume 21 b. The inside rim 13 preferably has a thin configuration (see Fig. 3); a thicker rim or a “fuller” rim starting from the bottom the frame element, of which the upper face (side, edge) would arranged according to the above, could also be applied.

Preferably, the difference between the first height and the distance is 0-2 mm, particularly preferably it is 0-1 mm such that the first height is the smaller value. If these are equal, it is preferable because in such a case the problem of colliding with the build head cannot occur (sideways with the inside rim 13 also present at a certain level), and in such a case the built object is also homogenous in this regard, it is not necessary to design a “step” into it.

In these preferred and particularly preferred cases in the first build step preferably building is performed on the inside rim 13, so in this embodiment it is not necessary to apply clamping arms, instead, during the separation the portion built on the inside rim 13 retains in place the three-dimensional object preform, i.e. , that status of object being currently.

In Fig. 4A-4C, the so-called “iris” arrangement of the build base unit according to another embodiment is illustrated, wherein the apparatus comprises a build base structure that has build base portions 32a-32c.

Also, in this arrangement according to the invention, two build heads (together with the corresponding arms, i.e. in the present embodiment similarly to the embodiment of Figs. 1A-1 B with support rod elements 16, and sliders, i.e. sliding members 14) are arranged on the vertical shafts (i.e. similarly using column elements 20) such that the ends of the build heads adapted to deposit filaments face each other. An intermediate element is arranged at the perpendicular partitioning plane of the vertical shafts and in the volume (space) encompassed by them.

The upper portion of the intermediate element is the coronal lock (clamping arm arrangement), and the bottom portion thereof is the iris (see the description of these below; in this embodiment preferably, this construction may be called an intermediate element).

The arms of the coronal lock (clamping arm arrangement) are radially closed around the initial layer (if it is needed). The iris undergoes an apart-opening movement in a direction parallel to the partitioning plane, freeing up the way for layer-build (layer building) from the second direction (this is the implementation of the movement mechanism in the present embodiment).

The top surface of the iris - i.e., in general, the starting build side of the build base unit - can be coated with an adhesion/separation helping (assisting) layer, which in its heated state facilitates the adhesion of the molten filament, while after being cooled down it releases the layers built on it without resistance. This adhesion/separation helping layer (coating) improves the efficacy of the adhesion and the separation, however, the apparatus is also operable (operational) without it, applying only tempering, or even without tempering (adhesion also happens and separation can also be brought about also in these cases).

Such adhesion/separation helping coatings are currently applied in 3D printing but with a different purpose, because in the invention separation from the starting build side of the build base unit is performed during the printing process, enabling the other build head to build on the surface that has just been separated from the starting build side.

The adhesion/separation helping coating for example has the following operating mechanism. The coating forms “islands” on the surface, thereby producing a rugged surface. As a result of thermal expansion, these islands expand (their surface area increases), so thanks to their greater size they provide better adhesion. Conversely, when the temperature decreases, the islands undergo shrinking, and - beside the decreasing adhesion surface area - shrinking itself facilitates separation (for example, these coatings are silicon carbide or polyethyleneimine based).

The coronal lock and the iris (the build base portions) can be tempered applying a heating cartridge, their temperature can be measured.

In the following, the configuration details of the iris arrangement applied in the present embodiment will be described.

In Fig. 4A, the build base unit configured by means the iris arrangement can be seen in its closed state. As shown in Fig. 4A, the build base unit has build base portions 32a-32c arranged, in the closed state, between the clamping arms 36a~36c making up a clamping arm arrangement. Because the clamping arms 36a-36c are adapted for clamping a built three-dimensional object (see the preform thereof in Figs. 4B- 4C), therefore at the start of the build process the three-dimensional object is built on the build base portions 32a-32c so that they be clamped by means of the clamping arms 36a-36c (in Fig. 4A the clamping arms 36a-36c are arranged in their base state around the build base portions 32a-32c). In case clamping arms are arranged there is no need to build the three-dimensional object on a component that rests in place after the movement (“movement into”) enabling the bottom build head to build the object, i.e., to apply a build-on like in the embodiment of Figs. 1A-3 wherein the object is built on the inside rim 13 of the frame element 10a.

Accordingly, in this embodiment the starting build side 39 of the build base unit is configured by means of mutually displaceable first, second and third build base portions 32a, 32b and 32c (the build side 39 is constituted by the sides of the build base portions 32a-32c facing upward in the figure), and preferably - in a way unrelated to this in that they can be applied in other embodiments - the frame element 31 has clamping arms for clamping a three-dimensional object preform (for an illustration of the latter see Figs. 4B-4C; the build side 39 is therefore a region encompassed by the clamping arms 36a-36c, building can of course be performed in this region such that at the appropriate stage the completed three-dimensional object can be clamped by the clamping arms 36a-36c). These two statements are also valid for the embodiments illustrated in Figs. 5A-6G (see below), and are also applicable in combination with such an embodiment according to the above (by providing an embodiment comprising clamping arms and build base portions based on a downwards-opening; such can be implemented by an opened-downwards build base unit with the constraint that in such a case building is not performed on the frame element, but instead in the appropriate stage the three-dimensional object preform is clamped utilising the clamping arms) wherein

- the movement mechanism is configured by means of a shaft for opening downwards passed through the build base unit and enabling to open it downwards, and

- the build base unit is arranged along the frame element in the in-use state and is opened downwards with respect to the frame element opposite the first build volume in the out-of-use state.

In the corresponding embodiment of the method, before to the movement (“movement into”) step, the three-dimensional object preform is clamped by means of the clamping arms (holding arms, retaining arms; this can also be applicable for various embodiments, for example embodiments based on plastic and metal filament deposition, because in both embodiments clamping is performed by means of clamping arms before the movement ("movement into”) step), and preferably - also in a non-dependent manner, because separation is not applied for example in embodiments based on filament deposition - after clamping the three-dimensional object preform and before the movement (“movement into”) step, the three- dimensional object preform is separated from the build base unit by displacing the build base portions.

It is noted here that the separation step applied in the present embodiment is optional, because the movement ("movement into”) step can also be carried out directly, without separation (for example, in the embodiment of Figs. 1A-3 such a separation involving a small displacement is not applied, instead the build base unit 10b is simply opened downwards). However, from the aspect of practical implementation it could be an advantage if a dedicated solution is provided for separation to ensure that it can be performed in a predictable way (for quality assurance reasons and appropriate performing).

It is also noted that in the present embodiment - in addition to the clamping arms 36a-36c being arranged at the starting build side 39 (and having shanks (handles) 34a-34c) - in the illustrated embodiment it also hods true that the clamping arms 36a-36c are (rotatably) attached to the frame element 31 (the region encompassed by the second frame element 31 is covered by the build base portions 32a-32c). In Fig. 4A first, second, and third moving arms 38a, 38b and 38c (arms for moving) are also shown that are adapted for moving the build base portions 32a-32c, as it can be better observed in Fig. 4B, and particularly in Fig. 4C.

Fig. 4B illustrates the state wherein a three-dimensional object preform 35 has already been built and is clamped by the clamping arms 36a-36c. It is noted that in Fig. 4B such a three-dimensional object preform 35 is illustrated that has a triangular shape with curved sides such that the clamping arms 36a-36c having a curved shape corresponding to the shape of the triangle’s curved side can firmly clamp it (a good grip can be achieved with a smaller or larger object with such a shape).

Expediently, in the case of applying the curved clamping arms illustrated in the figures, an object frame having curved sides (also shown in the drawings) is built for the preform, thereby providing a clamping base shape or a clamping circumference. The size of this may depend on the actual print geometry (due to the mutually corresponding curved shape of the clamping arms and the build frame, similarly curved build frames of different size can preferably be applied) i.e. on the size of the object to be built that is accommodated therein. It is sufficient to build this build frame at the clamping arms, i.e., with a height that enables the clamping arms to clamp it.

It can be appreciated, however, that the clamping arms 36a-36c having the illustrated configuration are also typically suitable for clamping three-dimensional objects of other configuration, because they are able to clamp from three sides three dimensional objects with highly varied shapes (of course, in certain cases not in the symmetrical manner as illustrated in Fig. 4B). As shown in Fig. 4B, in the arrangement for clamping the three-dimensional object preform 35 the end of each clamping arm 36a-36c extends over another clamping arm. A “step” is formed on the clamping arm 36b at the location where the clamping arms 36a and 36b meet each other, according to this configuration the clamping arm 36a can be moved as far as this step, indicating the maximum extent to which rotation about first auxiliary shafts 40 (short interconnecting shaft members, pivot pins, or rods that are adapted for interconnecting components enabling their relative rotation) is possible. The steps 33 arranged at the non-fixed ends of the shanks 34a- 34c of the clamping arms 36a-36b are also shown in Fig. 4A.

As the clamping arms 36a-36c are in their inward-turned state, in Fig 4B the rotatable connections of the moving arms 38a-38c to the frame element 31 by means of a second auxiliary shaft 42 and a third auxiliary shaft 44 and to the build base portions 32a-32c, respectively, become visible. In Fig. 4C it is illustrated how the build base portions 32a-32c can be rotated from their place by the help of these.

After bringing about the state illustrated in Fig. 4B, therefore, the three-dimensional object preform 35 is separated from the build side 39; in this embodiment the separation is performed such that the build base portions 32a-32c are rotated out from under the three-dimensional object preform 35 (this also is not a separation involving a small displacement, but it is the removal of the starting build side 39). This state is illustrated in Fig. 4C, showing that as the moving arms 38a-38c are displaced outward from the frame element 31 , they pull outward the build base portions 32a-32c.

The build base portions 32a-32c are rotatably attached at a single respective point to the frame element 31 by means of fourth auxiliary shafts 46, i.e. , the build base portions 32a-32c can be rotated about these points, and, in a manner illustrated in Fig. 4C, they can be rotated out from above the spatial region encompassed by the frame element 31 . This also requires that the auxiliary shafts 42, 44, 46 are also included: as shown in Fig. 4C, the connection point of the auxiliary shafts 42 of the moving arms 38a-38c to the frame element 31 is situated very close to the connection point of the auxiliary shafts 46, i.e., by the outward movement of the moving arms 38a-38c, the build base portions 32a-32c can be displaced out with the help of the auxiliary shafts 44 situated further from the auxiliary shafts 42 and 46. It can be seen that by removing the build base portions 32a-32c, the region encompassed by the frame element 31 is freed up, i.e. the three-dimensional object preform 35 is no longer bounded by them from below, enabling it to be built from below by the bottom build head.

The build base portions 32a-32c have a slightly modified circular sector shape, with a protrusion adapted for accommodating the auxiliary shafts 44 being formed on the outside curved sides lying inside the frame element 31 . The other two sides of the modified circular sectors are also curved; in the closed position (state) they are interconnected by a kind of rotation (see Fig. 4A), their adjacent sides fitting against each other, as one of them has a convex and the other a concave curve. Accordingly, the modified circular sectors together form a substantially circular shape that is adapted to cover the circular spatial region encompassed by the frame element 31 .

As shown in Figs. 4A-4C, rotating out the build base portions 32a-32c can be implemented (is feasible), because they are arranged such that their non-fixed corner is able to pass under the nearest clamping arm 36a-36c as it is not blocked by the auxiliary shaft 40 thereof. This outward rotation is started from a position (state) in which each build base portion 32a-32c is abutted against the adjacent one, which latter will turn towards the opposite side of the auxiliary shaft 40 arranged between them. The outward rotation is started from the position (state) illustrated in Fig. 4B.

To bring about the end position (state) illustrated in Fig. 4C, an inside ring 41 can also be arranged inside the ring-shaped frame element 31 such that it is rotatable with respect to the frame element 31. In Fig. 4C it is illustrated that a small displacement of the inside ring 41 has resulted in the auxiliary shafts 46 being moved out from under the clamping arms 36a-36c. The application of the inside ring 41 result in the opened-apart build base portions 32a-32c being slightly pulled away from the clamping arms 36a-36c such that they do not open under those, so it is ensured that they can be opened up sufficiently so as not to extend above the interconnecting space part encompassed by the inside ring 41 that forms a part of the frame element 31. The frame element 31 is however able to operate without applying the inside ring 41 , in such a case the amount of outward rotation may be affected to some extent by the clamping arms 36a-36c, under which the build base portions 32a-32c are rotated, but this effect can be so small that it does not affect the operation of the apparatus. The present embodiment can be preferably operated such that when the build process is completed, the finished three-dimensional object is dropped by the clamping arms 36a-36c, or it is descended - even in an automated manner - after being released by the clamping arms 36a-36c (and it is then preferably stored in this position, or is removed therefrom, i.e. the workpiece becomes prepared to be given out), and thereby the apparatus is again brought into a position suitable for starting the printing, wherein the build base portions 32a-32c are closed back to the state according to Fig. 4A.

In the present embodiment of the invention, therefore,

- the frame element 31 is arranged in an internally remaining manner,

- the build base portions 32a-32c are connected, rotatable parallel to the plane of the frame element 31 , to the frame element 31 (a frame element defines a plane in all cases in accordance with the region/portion encompassed by it, this portion is the interconnecting space part which has to be covered by the expediently flat build base portions, that is why they are rotatable parallel to the plane of the frame element), and

- the movement mechanism comprises moving arms 38a-38c each connected rotatable in the plane of the frame element 31 to the respective build base portion 32a-32c and to the frame element 31 , wherein

- in the in-use state, the build base portions 32a-32c are arranged abutting (pushed) against each other, along the interconnecting space part encompassed by the frame element 31 (such that they cover the interconnecting space part at one of its ends), and

- in the out-of-use state, the build base portions 32a-32c are displaced out from the interconnecting space part by means of the moving arms 38a-38c (terminating the cover of it).

In the embodiment of the method corresponding to this embodiment, in the movement (“movement into”) step, the build base unit is moved from its in-use state into its out-of-use state by displacing the build base portions out from the interconnecting space part encompassed by the frame element 31 . The printing process corresponding to the iris arrangement preferabiy has the foliowing steps.

1. Both build heads are at a safe vertical distance from the horizontal partitioning plane, in respective initial positions.

2. In an inserted end position of the intermediate element, the coronal lock (the clamping arm arrangement constituted by the clamping arms 36a-36c) is in an open state, while the iris is in a closed state (see Fig. 4A).

3. The coronal lock and the iris are both heated up (to a temperature of 60-120°C depending on the base material).

4. After reaching the desired temperature, filament deposition is started by the upper head on the top surface of the iris.

5. When the initial layer thickness is reached, the coronal lock is tightened around the initial layers, fixing their position (see Fig. 4B).

6. The upper head is halted and is vertically distanced from the iris.

7. Turning off the tempering, as well as optionally applying air or water cooling, the temperature of the iris decreases, as a result of which the initial layer yet manufactured can be easily separated from the anti-adhesion surface.

8. The iris opens up in a direction parallel to the partitioning plane (see Fig. 4C).

9. Heating of the coronal lock is switched on again.

10 Layer-build is continued applying the upper build head, while the bottom build head also starts filament deposition.

11. The two build heads operate simultaneously until the desired geometry is completed.

12. As a final step, the build heads approach their respective bottom and upper end positions, and the print geometry is removed from the apparatus for example in a manner described above (but it can alternatively also be removed from the apparatus by reaching inside, in case the latter has a housing structure, by grabbing the printed object before it is released by the clamping arms 36a-36c and removing it after its release by the arms 36a-36c).

In the following, the embodiments illustrated in Figs. 5A-6G will be described; these embodiments can be called “two-stage arrangements" (two embodiments that are similar in many respects). By the two-stage configuration, the separation of the middle layer built by the upper head from the object table and moving-out the object table from the way of the bottom build head are implemented in two steps. First, the adhesion between the printed middle layer and the coating of the object table is “broken” by applying a small displacement (see Figs. 50 and 6G), then the object table is moved out along a constrained path, expediently applying a motor drive (see the movement rail solution above) to a side of the printing region such that meanwhile it is brought from its initial horizontal state into a vertical position (vertical state; see in more detail below; the moving out is illustrated in Fig. 6D).

In the two-stage embodiments, the object table is divided into sections (to circular sector-shaped build base portions that make up the object table, i.e. , the starting build side like cake slices). In an example the sections are dimensioned such that a useful print surface area with a diameter of 400 mm is obtained (typically, a useful surface area of this size is obtained from the sections without the clamping arms extending over them). The separation step is expediently implemented by a small- scale displacement (typically in the range of 2-3 mm) of the build base portions.

The build base portions can be displaced by:

1. Moving them simultaneously in radial directions (i.e., pulling them apart simultaneously in a manner illustrated in Fig. 5C)

2. Moving them vertically in an intermittent manner (i.e., the three portions are pulled apart individually, for example moved one after the other)

3. Moving them simultaneously in a vertical direction (for an illustration see 6G)

4. Moving them intermittently in a vertical direction

In the second step, the object table can be moved out:

1 . By opening it downwards (this is applied in the embodiment of Figs. 1 A-3, except that in this case the build base portions are arranged on the starting build side of the build base unit for carrying out separation, their arrangement relates also in points 2 and 3 below; in such a case room is left in the frame element for the separation displacement, and the sections can also be moved downwards, like in Fig. 6G).

2. On a turning path with rollers on its sides (this is illustrated in Fig. 6D; in relation to this see also the movement rail solution above). 3. By a combination of an opening downwards and a vertical dropping movement (in such a case, after opening it downwards the build base unit is also released and is “dropped”, i.e., it is guided downward utilising e.g. some kind of guide rail solution).

The preferred steps of the printing process applicable with the two-stage arrangement are specified below.

2. In an inserted end position of the intermediate element (in this embodiment, the two-component frame element assembly comprising the coronal lock is preferably called the intermediate element), the coronal lock (clamping arm arrangement 56, see Fig. 6A) is open, and the iris that is formed by the object table sections, i.e., the build base portions 52a~52c and that in this embodiment forms the starting build side with its side facing the first build head is in a closed state (see Fig. 5A).

3. The coronal lock and the object table sections are both heated up (to a temperature of 60-120 °C depending on the base material).

4. After reaching the desired temperature, filament deposition is started by the upper head on the top surface of the object table sections.

5. When the initial layer thickness is reached, the coronal lock is tightened around the three-dimensional object formed from the initial layers, fixing its position (see Fig. 5B).

6. The upper build head is halted and is vertically distanced.

7. Turning off the tempering, or optionally, applying air or water cooling, the temperature of the object table sections is decreased (preferably by introducing air or cooling liquid/water under the object table sections, preferably in a closed channel that is in heat transfer contact with the object table sections; such a channel can be configured e.g. in the movement support element arranged under the object table sections, cf. a movement support element 64 in Fig. 6E; the object table sections are for example re-cooled by air via a heat transfer surface increased utilising cooling fins), as a result of which the initial layer yet manufactured can be easily separated from the anti-adhesion surface.

8. The object table sections undergo a short displacement in a radial or vertical direction (see Fig. 5C or Fig. 6G) 9. By turning 90 degrees relative to its original position (state), the object table is moved out into the bottom portion of the side of the print space (the result of this, i.e. that the object table is not present, is illustrated in Fig. 5D; the manner of displacement can be observed in Fig. 6D - it is preferably moved downwards into such a position wherein it does not hinder the later removal of the completed three- dimensional object).

10 Heating of the coronal lock is switched on again.

11 . Layer-build of the upper build head is continued, and the bottom build head also starts filament deposition.

12. The two heads operate simultaneously until the desired geometry Is completed.

13. As a final step, the build heads approach their bottom and upper end positions, and the intermediate element comprising the print geometry (a portion thereof belonging to the frame element) can be removed from the spatial region encompassed by the vertical supports in a direction parallel to the horizontal partitioning plane.

The above can be interpreted with the help of Figs. 5A-6G, which schematically illustrate the embodiments outlined above (basically two embodiments, one being illustrated in Figs. 5A-6D, and another embodiment, differing in certain details being illustrated in Figs. 6E-6G). The embodiments that will be described below have it in common that the build side is configured by means of mutually displaceable build base portions (for an identification of these, see below), and that the apparatus has clamping arms (in the two embodiments, these are the clamping arms 56a-56c, which are not shown in Figs. 6E-6G because these figures are intended to schematically illustrate other features) arranged at the build side of the build base unit for clamping a three-dimensional object preform.

In addition to illustrating another embodiment of the apparatus in top view, Figs. 5A- 5D also show certain phases of the corresponding method embodiment. In the present embodiment, the starting build side 59 is configured by means of build base portions 52a-52c, with clamping arms 56a-56c being arranged around them in an open state thereof, that is, a state in which they are not utilised for clamping the three-dimensional object preform. As shown in Fig. 5B, the clamping arms 56a-56c are rotated inward to clamp the three-dimensional object preform 55, in which state the damping arms 56a-56c overlap each other (they are configured such that such overlapping is possible).

As can be seen In Figs. 5A-5D (and similarly in Figs. 7A-7D), the fixed end of the clamping arms 56a-56c (shown schematically) is situated at the circumference (is rotatably attached to a respective frame element), and the adjacent clamping arm extends above a further portion of the clamping arm, and with its end, the investigated clamping arm extends above the other adjacent one. Accordingly, the clamping arms 56a-56c are expediently configured such that their initial portion is situated slightly lower in order that the adjacent clamping arm can extend above it (cf. the arrangement of the clamping arms 36a-36c in Figs. 4A-4C, where this is implemented applying steps 33), while their end situated further from the attachment location being situated slightly higher.

The build base portions applied In certain embodiments of the invention are typically flat (this is also indicated by the fact that they form the starting build side), they could also be called “build plates (sheets)” or, if the starting build side is considered a “plate element” due to its typically circular shape (although disc elements with other shapes, such as rectangular, hexagonal, octagonal, etc. shapes could also be conceived), then they could also be termed disc portions or disc sectors.

In Fig. 5A the three-dimensional object preform 55 is shown that is built on the build base unit 52 (see Fig. 5C). The preform can have an arbitrary shape, it has only for illustration purposes the illustrated rounded-corner triangular shape shown in Figs. 5A-5D, and has the geometric shapes in its mesh-filled region. This illustration indicates that it may have arbitrary shape that is suitable for building, also indicating that the curved triangle shown in the figures is expediently arranged around them as a clamping contour. The clamping contour is connected to the print geometries and shape portions by the illustrated mesh fill.

In Figs. 5B-5D it is also illustrated how the clamping arms 56a-56c clamp the three- dimensional object preform 55. It will be comprehended that by closing the clamping arms 56a-56c preforms for three-dimensional objects of other arbitrary shape can also be clamped. However, proper fitting of the clamping arms 56a-56c on the three- dimensional object preform 55 is accidental. Fig. 5B therefore illustrates the state wherein the clamping arms 56a~56c are applied for clamping the three-dimensional object preform 55 such that it can be separated from the build base portions 52a-52c. The process (manner) of separation applied in this embodiment is illustrated in Fig. 5C, showing that by radially pulling apart the build base portions 52a-52c (the gaps between them can be seen in the figure thanks to the mesh-like configuration of the three-dimensional object preform 55) the three-dimensional object preform 55 is separated from them while keeping it clamped with the clamping arms 56a-56c.

Fig. 5D shows the state wherein the build base unit 52 including the build base portions 52a-52c is removed. As shown by the illustration, the base unit does not comprise anything else than the build base portions 52a~52c; however, it must of course comprise for example structural components providing the radial pull action. Anyway, in the state according to Fig. 5D the entire build base unit 52 is removed to enable building of the three-dimensional object preform 55 from below (i.e., opposite the side that can be seen in the top views shown in Figs. 5A-5D).

Figs. 6A-6D show in side view the respective positions (states) corresponding to Figs. 5A-5D, showing in addition the position of a first build head 54a and a second build head 54b (the nozzle adapted to feed the build material for carrying out filament deposition is illustrated by a small needle-like portion facing toward the central part). The clamping arms 56a-56c are not shown separately; in Figs. 6A-6D the clamping arm arrangement 56 (coronal lock) is shown. Based on the illustration the status of the clamping arms 56a-56c cannot be established, i.e. if they are in their open or closed (clamped) position.

Fig. 6A shows the initial state, when the three-dimensional object preform 55 is built by the first build head 54a into between the clamping arms 56a-56c of the clamping arm arrangement 56 (accordingly, in this embodiment a first operational step S200 is illustrated in Fig. 6A). The three-dimensional object preform 55 can be seen in side view under and above the clamping arm arrangement 56 as it is seated on the build base unit 52 (the vertical lines schematically indicate, in side view, the lines where the adjacent build base portions contact each other). The first build head 54a is close enough to the three-dimensional object preform 55 that it is able to build it. In Fig. 6B, the first build head 54a has stopped building, and is being distanced from the three-dimensional object preform 55, while the clamping arm arrangement 56 closes around the three-dimensional object preform 55 (i.e. , clamps it; accordingly, in this embodiment a clamping operational step S210 is illustrated in Fig. 6B).

Fig. 6C, which illustrates a separation operational step S220 in this embodiment, is very similar to Fig. 6B with regard to the position of the depicted components. At the same time, it can be observed that in the two figures the build base unit 52 is shown to have different width, according to the pulled-apart position of the build base portions 52a-52c of the build base unit 52 (cf. Fig. 5C).

According to the above, Fig. 6D illustrates the removal of the build base unit 52, i.e., in this embodiment, a movement (“movement into”) step S230. As shown in the figure, after moving (“moving into”) the base unit into the rotated sideways position, the three-dimensional object preform 55 remains clamped in the clamping arm arrangement 56 between the build heads 54a, 54b, with its bottom portion being freed up in the direction of the second build head 54b such that the three- dimensional object preform 55 can be built further by the second build head 54b.

According to the illustration of Figs. 5C, 6C, in the embodiment of Figs. 5A-6D the build base portions 52a-52c are configured in a radially divided manner starting from the central point of the starting build side 59, to be displaceable in a radial direction by a first separation displacement relative to each other. In the corresponding embodiment of the method, separating of the three-dimensional object preform is carried out by displacing the build base portions 52a-52c by the first separation displacement.

The first separation displacement is therefore a distance covered in the radial direction (path) that helps separating of the three-dimensional object preform 55. As it was mentioned above, in the case of usual print dimensions a radial displacement of a few millimetres is required for that, i.e., in an embodiment the first separation displacement is between 1 -10 mm, preferably between 1 -5 mm, particularly preferably between 2-3 mm (this displacement expediently has a constant value irrespective of the print size, that is, the effective diameter of the starting build side). According to the above, Figs. 6E-6G illustrate an embodiment that has certain details that are different from the embodiment illustrated in Figs. 5A-6D. However, its features that are not visible in Figs. 6E-6G are identical to the embodiment described in Figs. 5A-6D.

Fig. 6E a build base unit 62 is illustrated schematically in side view. At the top of the figure build base portions 63 can be seen (Fig. 6F illustrates in top view the arrangement of build base portions 63a-63c: in a manner analogous to the build base portions 52a-52c), in side view they are illustrated by a single line. Fig. 6E is also intended to illustrate - as it was touched upon previously - that for the movement of the build base portions 63a-63c a movement support element 64 is required (expediently arranged under them), which in the present embodiment provides the movement of the build base portions 63a-63c illustrated in Fig. 6G (a schematic depiction of the mechanism required for radial movement could be the same).

The arrangement shown in Fig. 6E is illustrated in Fig. 6F from the direction “A” indicated in Fig. 6E, such that the configuration of the build base portions 63a-63c becomes visible.

Likewise, the arrangement is illustrated from the direction “B” shown in Fig. 6E in Fig. 6G. However, what is illustrated in Fig 6G is not simply the base state of the arrangement - i.e. , the state wherein the build process is performed on the build base portions 63a-63c, that is, the three-dimensional object preform is supported thereon (the build base portions 63a and 63b are shown in thick lines, separated from each other; of course, the distance between them in the base state is not necessarily proportional to the illustrated dimensions of the build base portions 63a, 63b as they can be brought closer to each other in the base state, expediently also such that there is no gap between them, the gap is therefore basically shown for the sake of illustration). Additionally, the separation state of the build base portions 63a, 63b - into which state they are moved down for separating the three-dimensional object preform built on the build base portions 63a-63c - is also indicated in dashed lines. The build base unit (object table) therefore preferably has multiple “storeys,” i.e. , it is a more complex assembly, of which the topmost layer is constituted by the object table sections (build base portions). This “multi-storey” configuration and the displacement of the object table sections are schematically illustrated in Fig. 6G. Furthermore, in accordance with the above, in Fig. 6G the dashed line indicates the vertical displacement the inner peaks of the object table sections. This is therefore an alternative mode of separation from the printed object (the current state of the three-dimensional object).

According to the above, in this embodiment the build base portions 63a-63c are configured to be displaceable relative to each other, by a second separation displacement in the direction of the second build volume 21 b. In the corresponding embodiment of the method, separating of the three-dimensional object preform is carried out by displacing the build base portions 63a-63c by the second separation displacement.

The second separation displacement is typically smaller than the first separation displacement mentioned above. In a possible embodiment, its value is in the range of 0.1 -5 mm, preferably of 0.5-4 mm, particularly preferably 1 -3 mm.

By means of this movement the build base portions that typically adhere to the three- dimensional object preform are pulled off, i.e., the adhesion is released by applying a displacement in a direction perpendicular to the adhered surface. In the abovedescribed embodiment employing a first separation displacement, adhesion is released by a displacement in a tangential direction relative to the adhered surface.

In the following embodiment, the three-dimensional object can preferably be built by fused metal filament deposition (or by feeding other such materials whereby no separation is applied). To achieve that, the embodiment illustrated in Figs. 7A-8D is expediently applied.

A delta-shaped configuration can also be possibly applied in the metal deposition case. In such a case, due to the additional components required by laser filament fusing, the build head has a greater mass, and therefore precise positioning is feasible only with slower movement. However, because fusing of the metal filament also requires more time in such a case, this will not cause a problem, i.e., the main limiting factor for build speed is not the speed reduction resulting from the extra weight of the head.

Similar to the above embodiments, two build heads are arranged on the vertical shafts (together with the corresponding arms and sliders) such that the ends (sides) of the build heads adapted to deposit filaments face each other. An intermediate element is arranged in the perpendicular partitioning plane of the vertical axes and in the space encompassed by them (the assembly comprising a frame element provided with the coronal lock is preferably called an intermediate element also in this embodiment; see further below). Under the intermediate element, there can be found, as a separate unit, the downward-moving object table (in this embodiment, a build base unit 72; the frame element is not shown in this embodiment).

In this embodiment, the intermediate element has a frame-like configuration (has a portion configured as a frame element), the coronal lock (clamping arm arrangement) is arranged at its top plane and is open in the centre. The intermediate element can be moved - like a drawer, parallel to the partitioning plane - into and out of the spatial region encompassed by the vertical shafts (the print space) by means of a rail mechanism, such that during the insertion an appropriate position is provided by a bumper end stand, while it can be freely removed from the apparatus after the print process has been completed.

The arms of the coronal lock (clamping arm arrangement) are able to close around the starter piece in a radial direction. The starter piece also constitutes a three- dimensional object preform, such one that was not produced in the apparatus according to the invention but in another manner, i.e., is available in a finished condition (in this case such a preform is built in the first build step, and accordingly, in this embodiment the building of the three-dimensional object preform by the first build head is enabled on the starting build side such that building is carried out on an existing preform). The starter piece preferably has parallel opposite sides, it is preferably a metal perforated object plate with a thickness preferably in the range of 1 -5 mm, particularly preferably 1 -2 mm (due to its thin configuration and the typically low number of build layers it can also be called a starter plate) that is applicable as a starter plane for the upper and bottom build heads, and it is expediently made of the same metal as the metal filament applied for printing.

The coronal lock and the starter piece can be tempered, and their temperature can be measured. Filament deposition is carried out directly on this starter piece from both sides, and, after the print process is finished, the completed geometry can be removed from the print space together with the object plate by means of a rail mechanism, and by opening the coronal lock the starter piece becomes removable together with the useful geometry built on it from both sides.

The printing process utilising fused metal filament deposition applied in the present embodiment preferably has the following steps.

1. Both build heads are at a safe vertical distance from the horizontal partitioning plane, in an initial position, while the coronal lock is in an open state.

2. The starter piece is placed on the object table (on the build base unit such that it supports the starter piece), and the coronal lock is closed around it (it is clamped by the clamping arm arrangement).

3. The starter piece is preferably heated up.

4. After reaching the desired temperature, filament deposition is started by the upper head on the top surface of the starter piece.

5. The object table is removed, followed by starting filament deposition on the bottom surface by the bottom head.

6. The two heads operate simultaneously - with continuous measuring of the workpiece temperature and applying cooling if necessary - until the desired geometry is completed.

7. As a next step, the build heads approach their bottom and upper end positions, and the frame element including the print geometry can be removed from the space part encompassed by the vertical shafts in a direction parallel to the horizontal partitioning plane.

8. The arms of the coronal lock are opened up, and the starter piece and the geometry built on it from both sides can be removed.

Metal filament fusing can for example be carried out by a laser beam that has a typical intensity <106 W/cm2 in the case of various non-alloy and heavily alloyed steels. The starter piece is therefore expediently supported and heated by the build base. To prevent any displacement, it is expedient to print on the starter piece only after being clamped.

A three-dimensional object preform made of metal would typically be impossible or difficult to separate from the build base unit, because the build process requires the use of significantly higher temperatures that would irremovably fuse the applied metal filament to the build base unit. This is why in this embodiment a starter piece is preferably applied, on which printing is performed by the upper head, and, after the movement ("movement into”) of the build base unit, by the bottom build head.

In this case, the build base unit has a supporting role, i.e. , the starter piece can be prepared on it. In this embodiment, too, preliminary tempering (heating) of the starter piece is optionally provided by the build base unit. It is also preferable to provide heating of the starter piece by means of the build base unit (object table) because it is more preferable to apply it for heating than the clamping arms so that the material of the three-dimensional object does not solidify on them.

The build base unit thus also provides initial heating and allows for the prevention of building on a cold object already at the start of the process (this a kind of “hot start”). When the starter piece is heated through, the build base unit (object table) can be removed.

The embodiment illustrated in Figs. 7A-8D, i.e., an embodiment with such a configuration, is suitable for plastic filament fusing, that is, for the set of applicable materials with which separation is feasible.

In the present embodiment, the upper (first) build head is constantly in operation and provides an above tempering during the build process. The build process is expediently started applying the bottom (second) build head, followed by removing the build base unit until it is not too thick (for example, 2-3 mm), because sufficient tempering is provided by the upper build head until then.

In the case of plastic filament fusing, the build process is expediently suspended during separation and movement ("movement into”), however, in this case it can preferably be carried on during these events, or a safety distance can also be maintained, as can be seen in Fig. 8D. Even If the build process is not suspended, the build base unit is expediently removed rapidly (the upper build head may be stopped for example to prevent instability in layer-build for sure, however, removal is expediently performed rapidly).

In this embodiment, the operation of the apparatus, and in relation to that, also the steps of the method are presented in the top views of Figs. 7A-7D and the side views of Figs. 8A-8D. As can be seen from the figures, there are several commonalities between the present embodiment and the embodiment of Figs. 5A-6D, so in relation to certain features that are visibly unchanged and have already been described, a reference is made to the description related to these figures.

Like in Fig. 5A, in Fig. 7A a build base unit 72 is shown in its in-use state, wherein clamping arms 76a-76c encompass the build base unit 72, which in the present embodiment has a continuous surface on the starting build side 79 thereof.

In accordance with the above, at the start of the build (build process), a three- dimensional object preform 75 is arranged on the build side 79. (this is shown to have different details with respect to the three-dimensional object preform 55; in the case of printing utilising a metal material it is a difference between the preforms 55 and 75 that, while the latter essentially shows a perforated plate that is inserted into the apparatus when already “completed”, and the layers are started to be deposited on it only after clamping it - hence the different appearance shown -, the former is built from the start by the apparatus; with respect to the exemplary configuration details illustrated, and to the shape of the three-dimensional object preform 75 further reference is made to the description above in relation to the embodiment illustrated in Figs. 5A-6D). In accordance with the above, therefore, in this embodiment the build base unit 72 is also adapted for supporting the three- dimensional object preform 75 (which at this stage can also be called a starter piece; it could therefore be described that in the first build step building on the starter piece is performed and in this way a preform adapted to be build further is formed), that is, at the start of the print (build) process it can be get there ready such that it can be subjected to further printing (building) first by the first build head, and then by the second build head. The build base unit 72 may at the same time also provide heating to the three-dimensional object preform 75. Fig. 7B illustrates that the three-dimensional object preform 75 is clamped by means of the clamping arms 76a-76c (accordingly, in the following the function of the build base unit 72 can only be the optionally provided heating), followed by subjecting to building the three-dimensional object preform 75 in a manner illustrated in Fig. 7C, which is illustrated in Fig. 7C by showing other geometrical shapes on a three- dimensional object preform 75’ thereby produced.

Fig. 7D illustrates the operational phase wherein the build base unit 72 is brought into the out-of-use state (cf. Fig. 8D), i.e. , after which this optionally provided heating opportunity is do not intended to use. In this state, like in Fig. 5D, building by means of the second build head is also made possible.

According to the above, Figs. 8A-8D - which also illustrated the stages illustrated in Figs. 7A-7D - also belong to this embodiment. Accordingly, in Fig. 8A an initial state can be observed, wherein a first build head 74a and a build head 74b (as they are adapted for building applying a metal material, they are referenced with different reference numerals than the build heads 54a, 54b) are distanced from the three- dimensional object preform 75, i.e., they are not building the preform.

Subsequent to Fig. 8A, Fig. 8B illustrates the state (cf. Fig. 7B) wherein the clamping arm arrangement 76 (coronal lock) formed by the clamping arms 76a-76c is closed around the three-dimensional object preform 75 (i.e., in this embodiment Fig. 8B illustrates a clamping operational step S250). In the state of Fig. 8B, the build operation has not started yet, so it (i.e., in this embodiment, a first build step S260) is illustrated in Fig. 8C wherein the first build head 74a has approached the three- dimensional object preform 75’ (which has been produced by building on an existing preform but is still called a preform because the three-dimensional object is produced by simultaneously applying both build heads). In accordance with the above, the stage wherein the build base unit 72 is removed to enable building by means of the second build head 74b is illustrated in Fig. 8D (that is, in this embodiment Fig. 8D illustrates a movement ("movement into”) operational step S270).

The term “build base unit” is used because in certain cases it has relatively complex configuration (though in certain cases - for example in the embodiment of Figs. 1 A- 1 B - its configuration is relatively simple). The build base unit is a unit in mechanical sense. Besides that, it could also simply be called a build base, but the terms “build base module” or “build base structure” are also applicable. The following are noted in relation to the individual embodiments:

- In the embodiment of Figs. 1A-1 B such a build base unit 10b is applied that has a flat configuration, has an elevated surface region 1 1 , and can be folded down by means of a shaft 17.

- In the embodiment of Figs. 4A-4B the build base unit is basically constituted by build base portions 32a-32c (these could collectively be referred to by a reference numeral 32 as a build base unit), because the moving arms 38a-38c form part of the movement mechanism.

- In the embodiment of Figs. 5A-6G, together with the build base portions 52a- 52c, a movement support element (schematically see the support element 64) preferably also forms a part of the build base unit 52, which movement support element has a supporting function and a function to make the movement of the build base portions. The build base unit 52 is preferably moved into the out-of- use state by means of rails (for example applying rails configured to have a “negative” shape, i.e. , a groove-and-roller arrangement where the roller moves in the groove, or rails having a “positive” shape, i.e., applying a path made up of profiled elements and a slide running on it; both configurations can have a straight or curved shape, the latter being preferably implemented applying curved elements).

- The build base unit 72 is configured integrally (contiguous), which allows for a simpler configuration compared to the build base unit 52 (but for example preferably both have the ability to be heated). It can expediently be moved on rails.

In case the frame element is of arrangeable type (i.e. it is not arranged in an internally remaining manner, but a replaceable that can be arranged for the given build task; in short, the apparatus is configured to be utilised in this way), then the frame element is removed from the apparatus together with the completed three- dimensional object after finishing each build task. In this implementation, therefore, the three-dimensional object can be removed from the apparatus together with the frame element (like together with a drawer or some kind of cartridge). Such embodiments can also be conceived in which the clamping arms are arranged on the frame element. In that case, the clamping arms are expediently clamped on the three-dimensional object while it is removed. This can also be implemented by means of a frame element that is in electrical contact with the apparatus, in which case the clamping arms can be loosened from the object by the apparatus by pressing a dedicated button.

It is also noted in relation to the build base unit that in the embodiment of Figs. 1A- 3 the frame element 10a can be internally remaining as well as removable, i.e. , its removal can be implemented even by pulling it out. If it is of the type that can be inserted from the side, then the build base unit 10b expediently has to be folded down when the frame element 10a is inserted, such that removal is not blocked by the protruding portion 11. It could also be inserted from another direction, i.e., not only from the direction of the shaft 17. This embodiment can expediently illustrate that in case the frame element is arranged in an internally remaining manner, then, as the three-dimensional object is built on the inside rim 13, it can also be removed from the open housing structure 15 by reaching into the object and removing (“abrading”) it from the frame element 10a.

In the embodiment of Figs. 4A-4C basically an internally remaining configuration of the frame element 31 is required. In this embodiment, the completed three- dimensional object will be held by the clamping arms 36a-36c. After the three- dimensional object is completed, it can be removed from the apparatus - for example by reaching therein as in the case of the housing structure 15 (this embodiment may also have such a structure) - by manually grabbing it and releasing the clamping arms 36a-36c.

In Figs. 5A-8D, the build base unit 52, 72 can be descended by such an extent that, in case the apparatus has a suitable opening, the three-dimensional object can be pulled out therefrom while it is attached by the clamping arms 56a-56c and 76a-76c to the frame element. For this reason, in this embodiment, application of a replaceable frame element is more expedient. In an embodiment of the apparatus according to the invention, the starting build side of the build base unit and/or the clamping arms are configured to be heatable (the part of the “or” option related to the starting build side of the build base unit can be combined with any embodiment of the invention).

In an embodiment of the method according to the invention, the build base unit is heated in the first build step (this heating can be expediently applied in the method in the case of applying any build base material). The method (and the apparatus) can also be performed (operated) without this type of heating (and other types of heating applied elsewhere), but in certain cases this may lead to reduced efficiency. However, such build base materials that do not require heating are also available.

With regard to the optionally applied heating, the following considerations can be observed.

In such embodiments wherein clamping arms are applied on the frame element, initially (i.e., in the first build step) it is sufficient to heat the starting build side, because the clamping arms of the coronal lock do not contact the built object, it is clamped only when tempering is just about to be finished, i.e., up to this it is not necessary to turn on their heating. When the build operation is continued, and heating can only be applied via the coronal lock, it is already expedient to turn on the heating of the clamping arms in case the print geometry requires it (if, for example, a support structure is started from the clamping arm). It is indicated by these considerations how important pre-heating is in case metal build base materials are applied.

It is noted that, if building on the frame element is applied, the frame element can also be configured to be heatable (as it was mentioned above). Heating and cooling of the components are applied on an appropriate schedule, such that it can effectively help building and the - optionally applied - separation.

The followings are also noted in connection with the invention. In accordance with the above, the invention provides a solution for implementing layer-build simultaneously from two opposite sides. Furthermore, in certain embodiments the initial layer thickness formed to correspond to central clamping applying for example clamping arms can be produced with such a pattern wherein the sectional shapes corresponding to the useful geometries are arranged in a grid mesh filling.

The invention is, of course, not limited to the preferred embodiments described in detail above, but further variants, modifications and developments are possible within the scope of protection determined by the claims.

Claims

- 53 -

CLAIMS An apparatus for manufacturing a three-dimensional object, comprising

- a material-feed first build head (12a, 54a, 74a) for building in a first build volume (21a), and

- a material-feed second build head (12b, 54b, 74b) for building in a second build volume (21 b), arranged opposite each other, c h a r a c t e r i s e d by further comprising

- a build base unit (10b, 52, 62, 72) having a starting build side (19, 39, 59, 79), and

- a movement mechanism for moving the build base unit (10b, 52, 62, 72) from an in-use state into an out-of-use state, wherein the build base unit (10b, 52, 62, 72)

- is arranged in its in-use state between the first build volume (21 a) and the second build volume (21 b) to enable building of a three- dimensional object preform (25’, 25”, 35, 55, 75, 75’) on its starting build side (19, 39, 59, 79) by means of the first build head (12a, 54a, 74a),

- in its out-of-use state, has been moved from its in-use state by the help of the movement mechanism to enable building of the three- dimensional object preform (25’, 25”, 35, 55, 75, 75’) by means of the second build head (12b, 54b, 75b). The apparatus according to claim 1 , characterised in that a frame element (10a, 31 ) is arranged in an internally remaining manner or can be arranged between the first build volume (21 a) and the second build volume (21 b), wherein the frame element (10a, 31 ) is configured to encompass an interconnecting space part. The apparatus according to claim 2, characterised in that

- the movement mechanism is configured by means of a shaft (17) for opening downwards passed through the build base unit (10b) and enabling to open it downwards, and - 54 -

- the build base unit (10b) is arranged along the frame element (10b) in the in-use state and is opened downwards with respect to the frame element (10a) opposite the first build volume (21 a) in the out-of-use state. The apparatus according to claim 3, characterised in that the build base unit (10b) has an elevated surface region (11 ) fitting, in the in-use state, into the interconnecting space part encompassed by the frame element (10a). The apparatus according to claim 4, characterised in that the frame element (10a) has a circumferential inside rim (13) extending from its inside circumference, and the elevated surface region (11 ) fits into the space part encompassed by the inside rim (13). The apparatus according to claim 5, characterised in that a first height of the elevated surface region (11 ) protruding into the frame element (10a) when fitted therein is smaller than or equal to a distance between a side of the inside rim (13) facing the first build volume (21a) and a surface of the frame element (10a) facing the second build volume (21 b). The apparatus according to claim 2 or claim 3, characterised in that the frame element (31 ) has clamping arms (36a-36c, 56a-56c) for clamping a three-dimensional object preform (35, 55, 75, 75’). The apparatus according to claim 7, characterised in that the starting build side (39, 59) of the build base unit (52, 62) is configured by means of mutually displaceable build base portions (32a-32c, 52a-52c, 63a-63c). The apparatus according to claim 8, characterised in that the build base unit (52, 62) comprises a movement support element (64) enabling displacement of the build base portions (52a-52c, 63a-63c) and arranged opposite the starting build side (59) thereof. The apparatus according to claim 9, characterised in that the movement mechanism is configured by means of movement rails and one or more - 55 - guide element adapted to be guided by each of the movement rails for moving the build base unit (52, 62) from its in-use state into its out-of-use state, wherein each movement rail and the corresponding one or more guide element are arranged in the apparatus and, in a manner fitting thereto, on the movement support element (64) of the build base unit (52, 62), respectively.

11 . The apparatus according to claim 9 or claim 10, characterised in that the build base portions (52a-52c) are configured in a radially divided manner starting from the central point of the starting build side (59), to be displaceable in a radial direction by a first separation displacement relative to each other.

12. The apparatus according to claim 9 or claim 10, characterised in that the build base portions (63a-63c) are configured to be displaceable relative to each other, by a second separation displacement in the direction of the second build volume (21 b).

13. The apparatus according to claim 8, characterised in that

- the frame element (31 ) is arranged in an internally remaining manner,

- the build base portions (32a-32c) are connected, rotatable parallel to the plane of the frame element (31 ), to the frame element (31 ), and

- the movement mechanism comprises moving arms (38a-38c) each connected rotatable in the plane of the frame element (31 ) to the respective build base portion (32a-32c) and to the frame element (31 ), wherein

- in the in-use state, the build base portions (32a-32c) are arranged, abutting against each other, along the interconnecting space part encompassed by the frame element (31 ), and

- in the out-of-use state, the build base portions (32a-32c) are displaced out from the interconnecting space part by means of the moving arms (38a-38c).

14. The apparatus according to any of claims 7-13, characterised in that the starting build side (19, 39, 59, 79) of the build base unit (10b, 52, 62, 72) - 56 - and/or the clamping arms (36a-36c, 56a-56c) are configured to be heatable. A method for manufacturing a three-dimensional object, in the course of which

- building, in a first build step (S100, S200, S260), a three-dimensional object preform (25’, 25”, 35, 55, 75, 75’) on a starting build side (19, 39, 59, 79) of a build base unit (10, 52, 62, 72) being in an in-use state by means of a first build head (12a, 54a, 74a) of oppositely arranged material-feed first build head (12a, 54a, 74a) for building in a first build volume (21a) and material-feed second build head (12b, 54b, 74b) for building in a second build volume (21 b), wherein, in the in-use state, the build base unit (10, 52, 62, 72) is arranged between the first build volume (21 a) and the second build volume (21 b),

- in a movement step (S110, S230, S270) after the first build step (S 100, S200, S260), the build base unit (10, 52, 62, 72) is moved by a movement mechanism from its in-use state into its out-of-use state, wherein, in its out-of-use state, the build base unit (10, 52, 62, 72) has been moved from its in-use state by means of the movement mechanism to enable building of the three-dimensional object preform (25’, 25”, 35, 55, 75, 75’) by means of the second build head (12b, 54b, 75b),

- in a main build step (S120) after the movement step (S110, S230, S270), building of the three-dimensional object preform (25’, 25”, 35, 55, 75, 75’) is continued by means of the first build head (12a, 54a, 74a), and is started by means of the second build head (12b, 54b, 75b). The method according to claim 15, characterised in that a frame element (10a) arranged in an internally remaining manner is available between the first build volume (21 a) and the second build volume (21 b) or the frame element (10a) is arranged therebetween, wherein the frame element (10a) is configured to encompass an interconnecting space part. The method according to claim 16, characterised in that - the movement mechanism is configured by means of a shaft (17) for opening downwards passed through the build base unit (10b) and enabling to open it downwards, and the build base unit (10b) is arranged along the frame element (10b) in the in-use state and is opened downwards with respect to the frame element (10a) opposite the first build volume (21 a) in the out-of-use state, and

- in the movement step (S110), the build base unit (10b) is moved from its in-use state into its out-of-use state by opening it downwards. The method according to claim 16, characterised in that

- the frame element (31 ) has clamping arms (36a-36c, 56a-56c) for clamping a three-dimensional object preform (35, 55, 75, 75’), and

- before the movement step (S230, S270), the three-dimensional object preform (35, 55, 75, 75’) is clamped (S210, S250) by means of the clamping arms (36a-36c, 56a-56c). The method according to claim 18, characterised in that

- the starting build side (39, 59) of the build base unit (52, 62) is configured by means of mutually displaceable build base portions (32a-32c, 52a-52c, 63a-63c), and

- after clamping (S210) the three-dimensional object preform (35, 55) and before the movement step (S230), the three-dimensional object preform (35, 55) is separated (S220) from the build base unit (52, 62) by displacing the build base portions (32a-32c, 52a-52c, 63a-63c). The method according to claim 19, characterised in that

- the build base unit (52, 62) comprises a movement support element (64) enabling displacement of the build base portion (52a-52c, 63a- 63c) and arranged opposite the starting build side (59) thereof, the movement mechanism is configured by means of movement rails and one or more guide element adapted to be guided by each of the movement rails for moving the build base unit (52, 62, 72) from its in- use state into its out-of-use state, wherein each movement rail and the corresponding one or more guide element are arranged in the apparatus and, in a manner fitting thereto, on the movement support element (64) of the build base unit (52, 62), and

- in the movement step (S230, S270), the build base unit (52, 62, 72) is moved from its in-use state into its out-of-use state by guiding the guide elements along the movement rails. The method according to claim 19 or claim 20, characterised in that

- the build base portions (52a-52c) are configured in a radially divided manner starting from the central point of the starting build side (59), to be displaceable in a radial direction by a first separation displacement relative to each other, and

- separating of the three-dimensional object preform (55) is carried out by displacing the build base portions (52a-52c) by the first separation displacement. The method according to claim 19 or claim 20, characterised in that

- the build base portions (63a-63c) are configured to be displaceable relative to each other, by a second separation displacement in the direction of the second build volume (21 b), and

- separating of the three-dimensional object preform (55) is carried out by displacing the build base portions (63a-63c) by the second separation displacement. The method according to claim 19, characterised in that

- the build base portions (32a-32c) are connected, rotatable parallel to the plane of the frame element (31 ), to the frame element (31 ), and the movement mechanism comprises moving arms (38a-38c) each connected rotatable in the plane of the frame element (31 ) to the respective build base portion (32a-32c) and to the frame element (31 ), wherein, in the in-use state, the build base portions (32a-32c) are arranged, abutting against each other, along the interconnecting space part encompassed by the frame element (31 ), and in the out-of- use state, the build base portions (32a-32c) are displaced out from the interconnecting space part by means of the moving arms (38a-38c), and - 59 -

- in the movement step, the build base unit is moved from its in-use state into its out-of-use state by displacing the build base portions (32a-32c) out from the interconnecting space part encompassed by the frame element (31 ). 24. The method according to any of claims 15-23, characterised by heating the build base unit (10, 52, 62, 72) in the first build step (S100, S200, S260).