Extendable building chamber and additive manufacturing system with extendable building chamber

Abstract

Examples of an extendable building chamber and a system for additive manufacturing using the extendable building chamber are described. The extendable building chamber has extendable walls and a build plate fixed to its base. A driver moves the extendable walls of the chamber upwards away from the base in a number of stepped positions between the first retracted position when the chamber wall is in a lowest retracted position towards a highest extended position when the chamber wall is at its highest extended position in order to facilitate deposition of new layer of powder during additive manufacturing while the build plate stays fixed.

Description

[0001] EXTENDABLE BUILDING CHAMBER AND ADDITIVE MANUFACTURING SYSTEM WITH EXTENDABLE BUILDING CHAMBER

[0002] Technical Field

[0003] The present disclosure relates to an extendable building chamber and a system and a method for additive manufacturing using the extendable building chamber.

[0004] Background

[0005] Additive manufacturing is a process that uses data computer-aided-design (CAD) software or 3D object scanners to direct hardware to deposit material, layer upon layer, in precise geometric shapes, so that the products are manufactured by melting the material (e.g., a powder), layer by layer. In the additive manufacturing systems, the material is added to create an object while in the traditional processes of product manufacturing, such as machining, casting, fabricating, it is often necessary to remove material through milling, machining, carving, shaping or other means. The additive manufacturing systems for metal products use laser or electron beam gun as a heat source for melting a metal powder or a metal wire, layer by layer. The process usually consists of two major steps: 1) depositing and spreading a thin layer (in microns) of the metal powder on the powder bed, and 2) melting the powder using a computer-controlled laser or electron beam. Typically, the building chamber comprises a build plate that is mounted onto a moving shaft. The metal powder is placed on the powder bed formed on the build plate. In order to deposit next layer of powder the build plate needs to move down in Z-direction. During melting of the powder and subsequent machining of the printed part, surface deformation can occur due to the movement and flexing of the build plate.

[0006] Therefore, improved systems are needed with build plate that is mechanically stable to avoid any deformations during operations.

[0007] Summary

[0008] In one aspect, an extendable building chamber is provided. The extendable building chamber comprises a track build structure with a base, a mounting structure that has two or more linear guides with a first end anchored in the base a second end opposite the first end and a supporting structure that is mounted to the second end of the two or more linear guides such that the supporting structure is movable up and down along the two or more linear guides. A build plate is fixed to a top surface of the base and it defines a powder bed thereon. A driver that is in communication with the supporting structure is configured to drive the supporting structure up and down along the two or more linear guides. The extendable building chamber further comprises a frame that is mounted and secured to the supporting structure such that it moves up and down along the two or more linear guides with the supporting structure and a track wall assembly with at least two extendable chamber walls that have a proximal end connected to a lower side of the frame and a distal end. The track wall assembly has at least two sets of plurality of interconnected tracks interconnected with two-part connectors formed along an upper edge, along a lower edge and at each side ends of each track to form the at least two extendable chamber walls. The extendable building chamber further comprises at least two rollers that are connected to the base of the build structure in proximity to the build plate such that a space is created between the rollers and the top surface of the base. The distal end of each of the at least two extendable chamber walls passes through the space under respective roller such that the roller presses the respective extendable chamber wall towards and against a seal of the build plate to seal the building chamber. When the driver moves the supporting structure upwards away from the base it moves upward the frame therefore raising upwards the at least two extendable chamber walls in a number of stepped positions between the first retracted position when the chamber wall is in a lowest retracted position towards a highest extended position when the chamber wall is at its highest extended position.

[0009] In another aspect, the building chamber comprises four extendable walls, two extendible walls that are parallel to each other having a plurality of interconnected comer type tracks forming two comer extendable walls and two of the extendible walls that are parallel to each other having a plurality of interconnected central type tracks forming two central extendible walls. Each comer type track has a curved elongated body with an elongated part and two comer pieces integrated to a respective side of the elongated part. The curved elongated body has a front part forming an outer face of the building chamber and a back part forming an inner face of the building chamber. An upper male connecting part is formed along an upper curved edge of the comer type track, a lower female connecting part is formed along a lower curved edge of the comer type track, a first side connecting part is formed at an end-face of one of the comer piece and a second side connecting part is formed at an end-face of the other of the comer piece. The lower female connecting part of one comer type track is configured to fit and mate with the male connecting part of the comer type track below and adjacent to such track. Each central type track has and elongated body with a front part forming an outer face of the building chamber and a back part forming an inner face of the building chamber. An upper male connecting part is formed along an upper edge of elongated body of the central type track, a lower female connecting part is formed along a lower edge of the elongated body of the central type track, a first side connecting part formed at a first side end of the elongated body and a second side connecting part formed at a second side end of the elongated body. The lower female connecting part of one of the central type track is configured to fit and mate with the male connecting part of the central type track below and adjacent to such track. The two side connecting parts of the central type tracks of the two central extendable walls are configured to fit and mate with the respective first or second side connecting parts of the adjacent comer type tracks from the respective adjacent comer extendable wall.

[0010] In yet another aspect, the first and the second side connecting parts of each of the comer tracks comprise a back lip portion with a toothed end-face, and the first and the second side connecting parts of each of the central type tracks comprise a side ledge and a toothed side endface extending out of the side ledge. The back lip portion of the comer tracks side connecting parts is sized and shaped to fit and mate with the respective side connecting parts of the central track forming an angled chopped connecting face between the central track and the comer track.

[0011] In one aspect, an additive manufacturing system is provided. The additive manufacturing system comprises the extendable building chamber, a powder dispensing system that has a powder feeder with a dispensing nozzle and a driver to dispense a powder layer with a predetermined height onto the powder bed, and an energy source coupled to a power supply to generate an energy beam onto a focal point on the powder bed where the powder is dispensed producing small volumes of melt pools that are solidified forming solidified layer.

[0012] In yet another aspect, a powder dispensing system is provided. The powder dispensing system comprises a powder feeder having a housing defining an inner cavity with an inlet and an outlet and a dispensing nozzle comprising a plurality of spring arms arranged in an array. Each spring arm has a first arm, a second arm spaced apart from the first arm forming a space therein between and a spring connected to a proximal end of the first arm and the second arm. The spring of each of the first arm and the second arm of each spring arm in the array allow the first and second arms of one spring arm in the array of spring arms to move independently one from another as well as independently from the arms of the other spring arms in the array. The space formed between the first and second arms of each spring arm in the array of spring arms form a dispensing channel extending between a proximal end and a distal end of the dispensing nozzle. A feeding head is formed at the distal end of the dispensing nozzle. The powder dispensing system further comprises s driver is also provided to vibrate the powder feeder and the dispensing nozzle to dispense the powder through the nozzle.

[0013] In one aspect, a method of manufacturing three-dimensionally shaped object using additive manufacturing system is provided. The method comprises steps of forming a powder layer onto a powder bed formed on a build plate fixed to a base of an extendable building chamber that comprises a extendable stepped chamber wall using a powder dispensing system; forming a solidified layer by irradiating the powder layer with an energy beam thereby melting or sintering the powder and subsequent solidification of the powder; driving the extendable stepped chamber wall to a next step of extended wall position and forming another solidified layer by newly forming a powder layer on the previously solidified layer and then irradiating the new powder layer with the energy beam, steps (i) to (iii) performed repeatedly; removing a remaining unsolidified powder of the solidified layer using a brush system; and machining the brushed surface of a shaped object precursor obtained during manufacturing of the three- dimensionally shaped object.

[0014] In addition to the aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and study of the following detailed description.

[0015] Brief Description of the Drawings

[0016] Throughout the drawings, reference numbers may be re-used to indicate correspondence between referenced elements. The drawings are provided to illustrate example embodiments described herein and are not intended to limit the scope of the disclosure. Sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility.

[0017] FIG. 1 is a perspective view of a build structure with an extendable building chamber in its lowest retracted position. FIG. 2 is a perspective cross-sectional view of the build structure and an extendable building chamber.

[0018] FIG. 3 is a perspective cross-sectional view of a build structure with an extendable building chamber in a highest extended position.

[0019] FIG. 4A is a side view of a build structure with an extendable building chamber and a pulling system for extendable building walls.

[0020] FIG. 4B is a perspective top view of a build structure with an extendable building chamber and a pulling system for extendable building walls.

[0021] FIGs. 5 A - 5D illustrate an example of a central type of a track for an extendable wall assembly of an extendable building chamber.

[0022] FIGs. 6A - 6C illustrate an example of a comer type of a track for an extendable wall assembly of an extendable building chamber.

[0023] FIG. 7 is a perspective view of a portion of an example of an extendable wall assembly showing a connection between a comer type track with a central type track.

[0024] FIG. 8 illustrate another embodiment of a central type of a track for an extendable wall assembly of an extendable building chamber.

[0025] FIG. 9 illustrate another embodiment of a comer type of a track for an extendable wall assembly of an extendable building chamber.

[0026] FIG. 10 is a side cross-sectional view of a powder dispensing system and a build plate.

[0027] FIG. 11 A-l IB show a cross-sectional view of a driver of a powder dispensing system.

[0028] FIG. 12 is a perspective cross-sectional view of the powder dispensing system and a build plate.

[0029] FIG. 13 is a side cross-sectional view of a brush tooling system for removing powder prior to machining a printed surface. FIG. 14 is a side cross-sectional view of a machining tooling system for machining a printed surface.

[0030] FIG. 15 is a perspective cross-sectional view of an additive manufacturing system with extendable building chamber and a milling system.

[0031] Detailed Description of Specific Embodiments

[0032] The present disclosure describes a build structure for an extendable building chamber with fixed build plate required in additive manufacturing systems is described herein below.

[0033] FIG. 1 illustrates a portion of an additive manufacturing system 100 with an extendable building chamber 10, a build plate 11 fixed to a base 22 onto which a powder bed is formed, a powder deposition system 14 configured to dispense a powder layer on the powder bed and an energy source 13 (see FIG. 15) coupled to a power supply to generate an energy beam onto a focal point on the powder bed where the powder is dispensed producing small volumes of melt pools that are solidified forming solidified layer of the manufactured object. The extendable building chamber 10 is mounted to a build structure 12 mounted on the base 22 and further includes a mounting structure 24 and a support structure 26 designed to support the extendable building chamber 10. In the illustrated example, the base 22 is rectangularly shaped but it can have any other shape (e.g., circular or oval) without departing from the scope of the invention. The base 22 has a top surface and needs to be solid and strong to carry the build structure 12 and any other parts of the additive manufacturing system 100.

[0034] The mounting structure 24 has at least two standing guides 36 onto which the support structure 26 is mounted. Each of the at least two standing guides 36 have a first end 31 anchored and secured in the base 22 and a second end 33 opposite the first end 31. For example, the standing guide 36 can be a linear guide or a shaft onto which the support structure 26 is slidably mounted. The support structure 26 can comprise at least two openings 27 with bushing such that the second end 33 of the at least two linear guides 36 passes through the respective opening 27. At least two drivers 42 that are in communication with the support structure 26 are configured to drive the supporting structure 26 up and down along the at least two standing guides 36 of the mounting structure 24. In one embodiment, each of the drivers 42 can comprise an electrical motor 43 and a linear actuator 45 configured to drive the support structure 26 along the standing guides 36 in Z-direction. For example, the electrical motor 43 can be a stepper motor with an endless belt and the linear actuator 45 can be a mechanical linear actuator, such as a ballscrew actuator / drive. The support structure 26 can further comprise an opening 37 with bushing to receive a portion of the mechanical ballscrew actuator 45.

[0035] In one embodiment, the mounting structure 24 can comprise four standing guides 36 erecting upward from the base 22. The first end 31 of each of the standing guides 36 is firmly anchored in the base 22. The support structure 26 can have four openings 27 to receive the second end 33 of the respective four standing guides 36. For example, the support structure 26 can be rectangularly shaped with openings 27 formed in proximity to each comer 21 of the rectangularly shaped support structure 26. Four drivers 42 can also be provided in proximity to each standing guide 36 to drive the support structure 26, and the support structure 26 will also have four openings 37 to receive a portion of the respective four mechanical liner actuators 45 of the four drivers 42.

[0036] A frame 16 of the extendable building chamber 10 is mounted and secured to the support structure 26. The extendable building chamber 10 comprises a track wall assembly 50 with at least two extendable chamber walls 52 having a proximal end 51 (FIG. 2) connected to a lower side 15 of the frame 16 and a distal end 53. The at least two extendable chamber walls 52 are extendable between a lowest (retracted) position of the extendable building chamber 10 (illustrated in FIG. 1) and a highest (expanded) position of the extendable building chamber 10 (illustrated in FIG, 3). The distal end 53 of the extendable chamber walls 52 can be free hanging as illustrated in FIGs. 1 - 3.

[0037] FIGs. 4A and 4B illustrate an example of another embodiment of additive manufacturing system 100’ with an extendable building chamber 10’ and atrack pulling system 110 configured to carry each extendable chamber walls 52. FIGs. 4A-4B illustrate rectangularly shaped support structure 26 with four extendable chamber walls 52 and four track pulling systems 110, one for each extendable chamber wall 52. Each track pulling system 110 comprises at least one pulling element 120 and a number of guiding elements 140 configured to positioned and guide the at least one pulling element 120. For example, the at least one pulling element can be at least one cable or cord. In the illustrated example, the pulling element is a cable 120. One end of the cable 120 is connected to one side end of the support structure 26 via first plate 130 that is secured to first side end of the support structure 26 and an opposite end of the cable 120 is connected to an opposite side end of the support structure 26 via second plate 132 that is secured to second (opposite) side end of the support structure 26 (FIG. 4B). The pulling cable is also inserted and secured into a cable channel 150 formed at the distal end 53 of each extendable wall 52, such that a pulling loop is formed using a pulling cable 120. The number of guiding elements 140 can comprise at least one lower guiding roller 142 and at least two upper guiding roller 144. The at least one lower guiding roller is mounted in proximity to the end side of the base 22. In the illustrated example, the lower guiding roller can comprise two spaced apart groves, such as a first groove 141 and a second groove 143. The first groove 141 is positioned in direction closer toward the first side end of the support structure 26 and first plate 130 while the second groove 143 is positioned in direction closer toward the second side end of the support structure 26 and the second plate 132, such that two pulling arms 120’ and 120” are formed of the pulling cable 120. The pulling cable 120 passes through and is guided by the first and second grooves 141, 143 keeping the two pulling arms 120’ and 120” separated and preventing them to slide close and interfere with each other in twisting or engaging fashion that may cause interruption of the manufacturing operation. In alternative embodiment, two separate lower guiding rollers 142 can be used to guide the cable 120 and form two pulling arms 120’ and 120”. The at least two upper guiding rollers 144 are mounted to an upper support structure 160 that is connected to the second end 33 of each standing guide 36 of the mounting structure 24. At least one of the at least two upper guiding rollers 144 is positioned in direction closer toward the first side end of the support structure 26 and first plate 130 guiding the first pulling arm 120’, and the other of the at least two upper guiding rollers 144 is positioned in direction closer toward the second side end of the support structure 26 and second plate 132 guiding the second pulling arm 120”. In the illustrated example, there are four upper guiding rollers 144, two of which are configured to guide the first pulling arm 120’ and the other two are configured to guide the second pulling arm 120”. First upper guiding roller 144a is aligned above the first groove 141 of the lower guiding roller 142 while third upper guiding roller 144c is aligned above the second groove 143 of the lower guiding roller 142. Second upper guiding roller 144b is aligned above the first plate 130 and connection point of the pulling cable 120 with the first plate 130, and fourth upper guiding roller 144d is aligned above the second plate 132 and connection point of the pulling cable 120 with the second plate 132. When the support structure 26 carrying the frame 16 of the extendable building chamber 10’ is in lowest (retracted) position of the extendable building chamber 10’, the second end 53 of each of the extendable walls 52 is in proximity to the respective lower guiding roller(s) 142. As the support structure 26 carrying the frame 16 of the extendable building chamber 10’ moves toward its the highest (expanded) position of the extendable building chamber 10’, each of the extendable walls 52, supported by the pulling system 110, are pulled away of the respective lower guiding roller(s) 142 towards the base of the building chamber 10’, and vice versa, as the support structure 26 carrying the frame 16 of the extendable building chamber 10’ moves downwards toward the lowest (retracted) position, each of the extendable walls 52, supported by the pulling system 110, are pulled toward the respective lower guiding roller(s) 142. In an alternative embodiment, the pulling system can comprise two separate pulling cables 120, one for each pulling arm 120’, 120”. In such arrangement, one end of the two cables is attached to the respective first and second plates 130, 132, while the other end of the two cables is attached to the respective end of the extendable wall 52, guided by the respective upper and lower guiding rollers 144, 142.

[0038] Each of the at least two extendable chamber walls 52 comprise a plurality of interconnected tracks 56 interconnected with linkages 58, described in details herein below, example of which are shown in details in FIGs. 5, 6, 8 and 9. Each of the linkages 58 comprise a number of male and female mating pairs formed in each track 56 such that a male part of one of the track 56 interlock with a female part of an adjacent track when the extendable chamber wall 52 is moving to an extended position to form the respective smooth and hermetically sealed inner wall surface of the building chamber 10. In one embodiment, extendable building chamber 10 can be rectangularly shaped and the track wall assembly 50 can comprise two central type extendable chamber walls 52’ parallel and opposing one from another and two comer type extendable chamber walls 52” parallel and opposing one from another. The central type extendable chamber walls 52’ have elongated tracks 56’ (examples of which are shown in details in FIGs. 5 A - 5D) having an elongated body 62’. The comer type extendable chamber walls 52” have elongated tracks 56” (examples of which are shown in details in see FIGs. 6A - 6C) having an elongated body 62” and two comers parts 64 integrally connected on each side of the elongated body 62”. The comer parts 64 of one of the comer type track 56” interlocks to the respective side end 65’ of the central type elongated tracks 56’ (side end 65’ that is facing the respective comer part 64) and similarly, the comer parts 64 of the other comer type track 56” interlocks to the respective end sides 65’ of the central type elongated tracks 56’ facing such comer parts 64 to form the walls 52 of the expandable rectangular build chamber 10.

[0039] The build structure 12 can further comprise at least two rollers 18 connected to the base 22 of the build structure 12 in proximity to the build plate 11 such that a space 13 (FIG. 2) is created between the rollers 18 and the top surface of the base 22. The distal end 53 of each of the at least two extendable chamber walls 50 can pass through the space 13 under respective roller 18 such that the roller 18 presses the respective extendable chamber wall 50 towards and against a seal 19 of the build plate 11 to seal the building chamber 10 to the build plate 11 and the top surface of the base 22. For example, the seal 19 can be a ceramic seal, or any other suitable seal, positioned around a circumference of the build plate 11 such that when the rollers 18 press against the extendable wall 52, the inner surface 61 of the extendable build chamber 10 sits tightly against the seal. Additional seal can be added to seal the chamber wall to the base 22. In the embodiment of rectangular extendable building chamber 10, two central rollers 18’ pressing against the central type of the extendable wall 52’ sit lower and closer to the top surface of the base 22 than the two comer rollers 18” that press against the comer type of the extendable wall 52” in order to accommodate the central type track 56’ to get up ahead of the comer type track 56” to allow the comer tracks 56” of the comer type extendable walls 52” to align and interlock with the adjacent central tracks 56’ of the central type extendable walls 52’. The minimum space of the roller 18 (space between the roller 18 and the base 22) from the base 22 can be 125% of a track height H (see FIG. 5A) and the maximum space of the roller 18 from the base 22 can be 150% of the track height in order to time the interlocking of the central and comer types tracks 56’, 56” of the adjacent walls 52”, 52”.

[0040] FIGs. 5A - 5D illustrate in details an example of a central type track 56’ with FIG. 5A showing a perspective view of the track 56’, FIG. 5B showing a long side (top) view of the track 56’, FIG. 5C showing a short side view of the track 56’ and FIG. 5D showing in details section A of FIG. 5C. Each track 56’ in the plurality of interconnected tracks 56’ has an elongated body 62’ with a front part 63’ forming a portion of the outer surface 63 of the chamber 10, a back part 61’ forming a portion of the inner surface 61 of the chamber 10 and two end sides 65’ at each end of the elongated body 62’. The central type track 56’ has stepped- like cross-section with the back part 61’ sitting lower than the front part 63’ in order to interconnect neighboring tracks 56’. An elongated upper edge face 66’ of the front part 63’ is positioned / sit in a plane that higher than the plane where an elongated upper edge face 73’ of the back part 61’ is positioned, and accordingly an elongated lower edge face 78’ of the front part 63’ is positioned higher than an elongated lower edge face 67’ of the back part 61 ’ defining the stepped-like shape of the central track 56’. The front part 63’ further comprises two protruding elements 69 extending outwards of its face. The two protruding elements 69 can be formed in proximity of respective side end of the track 56’ and can each comprise connectors 58’ and / or 59’. Each central type track 56’ comprises an upper male connecting part 74’ formed at the elongated upper edge face 66’ of the front part 63’and, a lower female connecting part 72’ formed at the elongated lower edge face 67’ of the back part 61’ and a side connecting part 71 (see FIG. 5B) protruding laterally out of each of the side ends 65’. The upper male part 74’ is formed by the elongated upper edge face 73’ of the back part 61” and a projection wall 75’ extending upwards of the elongated upper edge face 73’ therefore forming the elongated upper edge face 66’ of the front part 63’. The projection wall 75’ forms the upper stepped portion of the central track 56’ defining a ledge along the elongated upper edge face 73’ so that the upper edge face 73’ can be called also ledge 73’ herein after. The upward projection wall 75’ has a wedged top (see FIG. 5C) that is wedged / angled at an upper end 75” (see FIG. 5D) and is designed and sized to mate with the lower female part 72’ formed at the lower elongated edge face 67’ of the track 56’ above and adjacent to it.

[0041] The lower female connecting part 72’ is formed by the elongated lower edge face 78’ of the front part 63’ and an elongated projection wall 76’ (see FIG. 5C) that extends downwards of the elongated lower edge face 78’ therefore forming the elongated lower edge face 67’ of the back part 61’. The projection wall 76’ forms the lower stepped portion of the central track 56’ defining a ledge along the elongated lower edge face 78’ of the front part 63’, so that the lower edge face 78’ can be called also ledge 78’ herein after. A lower part 68’ of the protruding elements 69 can extend downward from the lower edge face 78’ of the front part 63’ forming groove portions 78” of the female connecting part 72’. There are two groove portions 78” defined by a portion of the projection wall 76’ and the lower part 68’ of the respective facing protrusion 69. The projection male wall 75’ of the male connecting part 74’ of the track 56’ fits into the groove portions 78” and sits on the elongated ledge 78’ of the female connecting part 72’ of the track 56’adjacent and above it, and the elongated female projection wall 76’ sits on the male ledge 73’ of the track 56’ adjacent and below it. The wedged wall of the projection 75’ is adjacent to an inner wall 79’ of the elongated projection wall 76’. The inner wall 79’ can have a curved lower end 79* to allow the female projection wall 76’ to easily mate within the wedged wall 75” of the male projection wall 75’ of the male part 74’.

[0042] The central type track 56’ further comprises the side connecting part 71 (see FIG. 5B) formed at each of the side ends 65’. Each side male part 71 comprises a projection 71’ and a side ledge 70’ which is formed by a respective side end-face of the back part 61’. The side connecting part 71 is configured to match and mate with a comer side connecting part 81 (see FIGs. 6A-6C) formed in the adjacent comer piece 64 of the comer type of track 56”. Connectors 58’ and 59’ are provided to flexibly join the adjacent central tracks 56’ one to another. A first connector 58’ is formed in an upper part 68” of the protruding elements 69 close to the upper edge face 66’ in proximity to each side end of the front part 63’ to rotatably join the track 56’ to the track 56’ above and adjacent along the elongated upper edge 66’ of such track 56’. A first track 56’ is connected to the lower side 15 of the frame 16 with its first connector 58’. A second connector 59’ is formed in the lower part 68’ of the protruding elements 69 close to the lower edge face 67’ in proximity to each side end of the front part 63’ to rotatably join the track 56’ to the track 56’ below and adjacent along the elongated lower edge face 67’ of such track 56’.

[0043] FIGs. 6A - 6C illustrate in details an example of a comer type track 56” with FIG. 6A showing a perspective view of the track 56”, FIG. 6B showing a top view of a long (elongated) side of the track 56” of FIG. 6A and FIG. 6C showing a bottom view of the long (elongated) side of the track 56” of FIG. 6A. Each track 56” in the plurality of interconnected tracks 56” has an elongated curvy-ended body 62” with a central part 82 and two integrated comer parts 64 formed at each end of the central part 82 forming the two curvy comer portions 64’ of the body 62”. The comer type track 56” has a front part 63” forming a portion of the outer surface 63 of the chamber 10 and a curvy back part 61” forming a portion of the inner surface 61 of the chamber 10. The comer type track 56”, similarly to the central type track 56’, has stepped- like cross-section with the back part 61” sitting lower than the front part 63” in order to interconnect neighboring tracks 56”. An elongated curvy-ended upper edge face 66” is formed along the upper edge of the front part 63” and is positioned / sit in a plane that is higher than the plane where an elongated curvy-ended upper edge face 73” of the curvy back part 61” is positioned, and accordingly an elongated lower curvy-ended edge face 78” of the front part 63” is positioned higher than an elongated curvy-ended lower edge face 67” of the curvy back part 61” defining the stepped-like shape of the comer type track 56”. The track body 62” further comprises two protruding elements 69” extending outwards of the front part 63” face. The two protruding elements 69” can be formed in proximity of respective side end of the track 56” (e.g., as part of the comer parts 64) and can each comprise connectors 58”.

[0044] Each comer type track 56” has an upper male part 74” that is formed along an elongated upper curvy edge face 66” and a lower female part 72”formed along an elongated lower curvy edge face 67”. The upper male part 74” is formed by the elongated curvy-ended upper edge face 73" of the curvy back part 61” and a projection wall 75” extending upwards of the elongated curvy-ended upper edge face 73” therefore forming the elongated curvy upper edge face 66” of the front part 63”. The projection wall 75” forms the upper stepped portion of the comer track 56” defining a ledge along the elongated curvy-ended upper edge face 73” so that the curvy upper edge face 73” can be called also curved ledge 73” herein after. The upward projection wall 75” can have a wedged top that is wedged / angled at an upper end and is designed and sized to mate with the lower female connection part 72” formed at the elongated curvy-ended lower edge face 67” of the track 56” above and adjacent to it.

[0045] The lower female connecting part 72” is formed by the elongated lower curvy-ended edge face 78” of the front part 63” and an elongated projection wall 76” that extends downwards of the elongated lower edge face 78” therefore forming the elongated lower edge face 67” of the curved back part 61”. The projection wall 76” forms the lower stepped portion of the central track 56” defining a ledge along the elongated curved lower edge face 78” of the front part 63”, so that the lower curved edge face 78” can be called also curved ledge 78” herein after. The projection male wall 75” of the male connecting part 74” of the track 56” sits onto the elongated curved ledge 78” of the female connecting part 72” of the track 56” adjacent and above it, and the elongated female projection wall 76” sits on the male curved ledge 73” of the track 56” adjacent and below it.

[0046] The curvy-ended body 62” of the comer track 56” comprises the comer connecting part 81 that is formed at an comer end face 83 of each comer piece 64. The comer connecting part 81 is formed by the back part 61” projecting forward of the comer part 64 forming a back lip portion 833 at the comer end face 83 sized and shaped to fit and sit onto the side ledge 70’ of the respective side end-face of the back part 61’ of the central track 56’. A front part 831 of the comer end 83 can also extend forward to form a groove 84 that is sized to receive the male projection 71’ of the side male part 71 of the central type track 56’.

[0047] In the embodiments illustrated in the FIGs. 5 and 6, all of the connecting parts have flat faces forming straight-line connecting line between adjacent elements. This may cause fine powder disposed on the powder bed to traverse through and across the straight connecting lineface compromising the quality to the manufactured parts. FIG. 7 illustrates another embodiment to of a central type track 156 and a comer type track 158 with a chopped / toothed connecting face 160 between the central track 156 and the comer track 158 to prevent powder leak.

[0048] FIG. 8 shows in detail an example of the central type track 156 with a chopped / toothed side end / face 160 of a back part 161. The central type track is similar to the central type track 56’ illustrated in details in FIGs. 5A-5D. Each central type track 156 comprises an elongated body 162 with a front part 163 forming a portion of the outer surface of the chamber, a back part 161 forming a portion of the inner surface of the chamber and two end sides 165 at each end of the elongated body 162. The central type track 156 has stepped-like cross-section with the back part 161 sitting lower than the front part 163 in order to interconnect neighboring tracks 156, as described herein before with respect to the track 56’. The front part 163 further comprises two protruding elements 169 extending outwards of its face. The two protruding elements can be formed in proximity of respective side end of the track 156 and can each comprise connectors 158. Each central type track 156 comprises an upper male connecting part 174 formed at the elongated upper edge face 166 of the front part 163 and, a lower female connecting part 172 formed at the elongated lower edge face 167 of the back part 161 and a side connecting part 171 protruding laterally out of each of the side ends 165. The upper male connecting part 174 and the lower female connecting part 172 are same as the upper male connecting part 74’ and the lower female connecting part 72’ described herein above with respect to the central type track 56’.

[0049] The side connecting part 171 is formed at each of the side ends 165. Each side connecting part 171 comprises a side ledge 170 which is formed by the respective side endface 160 of the back part 161. The side end-face 160 of the back part 161 is chopped / toothed side end / face that is configured to match and mate with a chopped / toothed comer side connecting part 181 (see FIG. 9) formed in the adjacent comer piece 186 of the comer type of track 158. In the illustrated embodiment the chopped side end-face 160 of the back part 161 comprises three toothed sections. Lowest toothed section 160’ is extending inward of the respective end 165 under sharp angle, while the middle section 160” and the upper toothed section 160* are closer to the respective side end 165. Person skilled in the art would understand that the chopped side end-face can have fewer or more toothed sections without departing from the scope of the invention. FIG. 9 illustrates in detail the comer type track 158 of FIG. 7 with a chopped / toothed comer side connecting part 181. Each track 158, similarly to comer track 56”, has an elongated curvy-ended body 182 with a central part 184 and two integrated comer parts 186 formed at each end of the central part 184 forming the two curvy comer portions 186 of the body 182. The comer type track 158 has a front part 183 forming a portion of the outer surface of the chamber and a curvy back part 185 forming a portion of the inner surface of the chamber. The comer type track 158, similarly to the comer type track 56”, has stepped-like cross-section with the back part 185 sitting lower than the front part 183 in order to interconnect neighboring tracks 158. Each comer type track 158 has an upper male part 194 that is formed along an elongated upper curvy edge face 196 and a lower female part 192 formed along an elongated lower curvy edge face 197. The upper male connecting part 194 and the lower female connecting part 192 are same as the upper male connecting part 74” and the lower female connecting part 72” described herein above with respect to the central type track 56”.

[0050] The curvy-ended body 182 of the comer track 158 comprises a comer connecting part 181 that is formed at a comer end face 193 of each comer piece 186. The comer connecting part 181 is formed by the back part 185 projecting forward of the comer part 186 forming a back lip portion 195 at the comer end face 193. The comer end-face 193 of the back lip projection 195 is chopped / toothed end-face that is sized and shaped to fit and mate with the respective chopped side end-face of the side connecting part 171 of the central track 156.

[0051] In one embodiment, the building chamber 10 can comprise only two extendable walls 52. Both of the extendable walls 52 can comprise a plurality of interconnected comer type tracks. In such embodiment the central type of tracks 56’ as described above are omitted and the comer type tracks used in such two walls chamber are similar to the comer type tracks 56”, 158 described above in relation to FIGs. 6 and 9. The difference is that the comer tracks used in the build chamber with two extendable walls have a side female partformed at one of the comer ends and a side male part formed at the opposite comer end. The side male part comprises a projection extending laterally from the comer end and two ledges on each side of the projection. The lateral projection of the side male part is sized to fit into the groove of the side female part of the other wall when the walls 52 extend to increase the height of the building chamber.

[0052] The first track 56’, 56”, 156, 158 of each set of the extendable track walls 52 is at the respective proximal end of the extendable chamber walls 52 forming the first end of the extendable building chamber 10, the upper edge 66’, 66”, 166, 196 of the first tracks 56’, 56”, 156, 158 being connected to the lower side 15 of the frame 16, wherein each subsequent track in each set of the plurality of interconnected tracks are connected to a preceding track such that the upper edge of the subsequent track is adjacent to the lower edge of the preceding track, such that the last track of each set of the plurality of interconnected tracks is forming the respective distal end 53 of the extendable chamber walls 52. A seal (e.g., a rubber seal) can be provided at the edges of each track to seal tightly the connection between the tracks and between the walls 52 when the building chamber 10 is in extended position.

[0053] The build plate 11 is fixed to the top surface of the base 22 and defines the powder bed onto which the powder dispensing system 14 dispenses a powder layer during additive manufacturing process. FIG. 10 shows the powder dispensing system 14 of the present invention. The powder dispensing system 14 can comprise a powder feeder 92 with a dispensing nozzle 94 and a driver 96 configured to provide vibrational oscillation to a housing 98 of the powder feeder 92 and the nozzle 94 to induce a flow of powder stored in an inner cavity 99 of the housing 98 out of the nozzle 94 and to form a powder layer with a predetermined height onto the powder bed 111. The dispensing nozzle 94 comprises a plurality of spring arms 95 arranged in an array. Each spring arm 95 has a first arm 91, a second arm 93 spaced apart from the first arm 91 forming a space 296 therein between. Each of the first and the second arms 91, 93 have a proximal end 101 connected to a spring 103. The spring 103 at the proximal end 101 of each of the first arm 91 and the second arm 93 of each spring arm 95 allow the arms 91, 93 to move / bend independently one from another as well as independent from the arms of the other spring arms 95 in the array. The space 296 formed between the two arms 91, 93 of each spring arm 95 in the array of spring arms form an dispensing channel to dispense a curtain of powder layer on the powder bed 111. The first arms 91 and the second arms 93 of the spring arms 95 move / bend independently along X and Y-directions so that the powder dispensing system 14 can continue dispensing powder layer on the powder bed 111 (e.g., on top of the solidified layer of the printed object) even if there is any unevenness form on the surface (e.g., unevenness 110 formed at the top surface of the printed object) without interrupting the manufacturing operation. A nozzle head 105 is formed at a distal end 104 of each of the first and second arms 91, 93. The proximal end 101 with the spring 103 of the spring arms 95 are connected to the powder feeder housing 98 at its lower end, so that the nozzle 94 vibrate / oscillate along with the powder feeder 92, however, the spring arms 95 will have their own harmonic frequencies over their length depending on a stiffness of the spring 103 (more flexible or stiffer depending on the requirements and the powder dispensed). The stiffness can be adjusted by the type of the spring material and the thickness / cross sectional stiffness of the springs 103. The distal ends 104 of the arms 91, 93 of each spring arm 95 in the array forming the nozzle head 105 can also help in leveling the powder layer by slightly compressing the powder at its top. The oscillation / vibration of the dispensing nozzle 94 can create a small vertical moving component (in Z-direction) which can provide tapping and compression of the powder, therefore higher density of powder on the powder bed before melting. The powder is dispensed out of the dispensing nozzle 94 described herein above as curtain to form the powder layer on the powder bed 111 as shown in FIG. 12.

[0054] The driver 96 of the powder dispensing system 14 can have a motor that drives / rotates a rotating shaft 97 mounted into an elongated opening 87 formed in an upper part of the housing 98. The rotating shaft 97 has an outer surface with number of peaks 90 and valleys 89 (see FIGs. 11A and 1 IB) forming cam-like projections thereon. Two followers structures 88 are mounted to the housing 98 on each side of the shaft opening 87. The two followers 88 are spaced apart and are positioned on an opposite side of the shaft opening 87. Each of the two followers has a head 86 protruding into the shaft opening 87. The interaction of the cam-like body of the surface of the driver’s shaft 97 with the followers 87 causes linear shaking and vibration of the feeder housing 98 and the nozzle 94.

[0055] FIG. 13 illustrated a brushing tool 200 that is used to brush off any powder remaining in the powder bed 111 after melting / sintering of the powder layer. The additive manufacturing system can comprise a milling spindle 1200 (see FIG. 15) with an automatic tool changer and a tool magazine (not shown) that has brush tools, cutting tools and many other tools. A control system 400 shown in FIG. 15 is programed to execute programmed instructions to start with brushing and removing the powder. After that the brush tool 200 brashes off the remaining powder of the powder bed 111 and the brush 200 is exchanged for a cutting tool 300 (see FIG. 14) and the controller 400 can send output signal to the milling machine to start machining of the printed surface of the printed layer(s). The step of brushing off the powder of the powder bed before machining helps to prevent the powder to friction weld onto the machining tool 300.

[0056] FIG. 15 illustrates an embodiment of the additive manufacturing system 100 with the extendable build chamber 10. The additive manufacturing system 100 has controlling system 400 preprogrammed to control the manufacturing process. The control system 400 can comprise an input unit, an output unit, a processing unit and a memory unit with stored pre- programmed instructions. The milling machine 1200 can be driven by its driver (not shown) along a X-direction along a X-linear guide 1210, along a Y-direction along an Y-linear guide 1220 and along a Z-direction along a Z-linear guide 1230. The driver of the milling machine 1200 can be any suitable electrical motor. The controlling system 400 is also in communication with the energy source 13 that is coupled to a power supply to generate an energy beam onto a focal point on the powder bed where the metal powder is dispensed. For example, the energy source 13 can be an electron gun configured to generate a high energy electron beam or a laser generating a high energy light beam. The energy source can comprise a number of optical elements to align and focus the generated energy beam onto the powder bed. The energy source can further comprise a driver configured to drive the energy source in X, Y and Z directions. The driver of the energy source is controlled by the controller 400 to adjust the position of the energy source and the focal point on the powder bed. The additive manufacturing system 100 can further comprise a number of position sensors to measure a position of the frame 16 of the building chamber 10 from the build plate. For example, the position sensors can be linear and / or rotary encoders. The position measuring signals are fed into the position measuring program of the controller 400 that calculates the position of the powder layer based on the position of the frame 16 from the build plate and send signals to the driver(s) 42 to extend the building chamber wall assembly for a precise step that correspond to a powder layer height.

[0057] In operation, once the metal layer is solidified, the driver 42 moves the supporting structure 26 upwards away from the base 22 such that it moves also upward the frame 16 therefore raising upwards the at least two extendable chamber walls 52. The driver 42 is configured to move the support structure 26 in small steps (in microns corresponding to the predetermined height of each powder layer) so that the extendable chamber walls 52 move upwards in a number of small positions between the first retracted position when the chamber wall is in its lowest retracted position towards the highest extended position when the chamber wall 52 is at its highest extended position. The drivers 42 can be an electrical motor, such as for example, a stepper motor, that can lift the at least two extendable stepped chamber walls 52 of the extendable build chamber 10 in incremental steps. With each step the least two extendable stepped chamber walls 52 are lifted for a height that corresponds to the predetermined height of the powder layer deposited onto the powder bed on top of the solidified layer. Once the new powder layer is deposit onto the powder bed, the controller 400 send instructions to the driver(s) of the energy source 13 (e.g., laser) to adjust the laser head(s) position along Z-direction (adjust the distance of the laser head(s) from the powder bed) and move the laser head(s) along the X and Y directions to melt the powder. After the powder on the powder bed is melted / sintered and solidified, the brush tool is mounted to the milling machine to brush away any remaining powder off the printed object and the powder bed before the brushing tool is exchanged with the cutting tool for machining the printed object. After the machining of the object, a new powder layer is deposited on top of the machined printed part and the steps are repeated. The steps of brushing and machining can be performed after each printed layer or after a number of printed layers (e.g., after every 4 / 5 layers are printed) depending on the controller’s pre-programed instructions.

[0058] While particular elements, embodiments and applications of the present disclosure have been shown and described, it will be understood, that the scope of the disclosure is not limited thereto, since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings. Thus, for example, in any method or process disclosed herein, the acts or operations making up the method / process may be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Elements and components can be configured or arranged differently, combined, and / or eliminated in various embodiments. The various features and processes described above may be used independently of one another, or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of this disclosure. Reference throughout this disclosure to “some embodiments,” “an embodiment,” or the like, means that a particular feature, structure, step, process, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in some embodiments,” “in an embodiment,” or the like, throughout this disclosure are not necessarily all referring to the same embodiment and may refer to one or more of the same or different embodiments. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, additions, substitutions, equivalents, rearrangements, and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions described herein.

[0059] Various aspects and advantages of the embodiments have been described where appropriate. It is to be understood that not necessarily all such aspects or advantages may be achieved in accordance with any particular embodiment. Thus, for example, it should be recognized that the various embodiments may be carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages as may be taught or suggested herein.

[0060] Conditional language used herein, such as, among others, "can," "could," "might," "may," “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or steps. Thus, such conditional language is not generally intended to imply that features, elements and / or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without operator input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular embodiment. No single feature or group of features is required for or indispensable to any particular embodiment. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.

[0061] The example calculations, simulations, results, graphs, values, and parameters of the embodiments described herein are intended to illustrate and not to limit the disclosed embodiments. Other embodiments can be configured and / or operated differently than the illustrative examples described herein.

Claims

Claims:

1. An additive manufacturing system comprising: a build structure that comprises:• a base,• a mounting structure having two or more linear guides with a first end anchored in the base a second end opposite the first end,• a supporting structure mounted to the second end of the two or more linear guides, the supporting structure being movable up and down along the two or more linear guides,• a driver in communication with the supporting structure and configured to drive the supporting structure up and down along the two or more linear guides; a build plate defining a powder bed is fixed to a top surface of the base; an extendable building chamber with a frame is mounted and secured to the supporting structure, the extendable building chamber includes a track wall assembly with at least two extendable chamber walls having a proximal end connected to a lower side of the frame and a distal end, the track wall assembly having:• at least two sets of plurality of interconnected tracks interconnected with two-part connectors formed along an upper edge, along a lower edge and at each side ends of each track to form the at least two extendable chamber walls; at least two rollers connected to the base of the build structure in proximity to the build plate such that a space is created between the rollers and the top surface of the base, the at least two rollers configured to press the respective extendable chamber wall towards and against a seal of the build plate to seal the building chamber; a powder dispensing system comprising a powder feeder with a dispensing nozzle and a driver to dispense a powder layer with a predetermined height onto the powder bed; andan energy source coupled to a power supply to generate an energy beam onto a focal point on the powder bed where the metal powder is dispensed producing small volumes of melt pools that are solidified forming metal layer, wherein when the driver moves the supporting structure upwards away from the base it moves upward the frame therefore raising upwards the at least two extendable chamber walls in a number of stepped positions between a first retracted position when the chamber wall is in a lowest retracted position towards a highest extended position when the chamber wall is at its highest extended position.

2. The additive manufacturing system of claim 1, wherein the building chamber comprises two extendable walls, each of the two extendable walls comprise a plurality of corner type tracks, each corner type track having a curved elongated body with an elongated part and two corner pieces integrated to a respective side of the elongated part, the elongated body having a front part forming an outer face of the building chamber and a back part forming an inner face of the building chamber, an upper male connecting part formed along an upper curved edge of the corner type track, a lower female connecting part formed along a lower curved edge of the comer type track, the lower female connecting part of one track configured to fit and mate with the male connecting part of the corner type track below and adjacent to such track, a side female connecting part formed at a first corner side end and a side male connecting part formed at a second corner side end, the side male connecting part of the tracks of one of the extendable wall configured to fit and mate with the side female connecting part of the adjacent track from the other of the extendable wall.

3. The additive manufacturing system of claim 1, wherein the building chamber comprises four extendable walls, two extendible walls that are parallel to each other having a plurality of interconnected comer type tracks forming two corner extendable walls and two of the extendible walls that are parallel to each other having a plurality of interconnected central type tracks forming two central extendible walls, each corner type track having a curved elongated body with an elongated part and two corner pieces integrated to a respective side of the elongated part, the curved elongated body having a front part forming an outer face of the building chamber and a back part forming an inner face of the building chamber, an upper male connecting part formed along an upper curved edge of the corner type track, a lower female connecting part formed along a lower curved edge of the corner type track,a first side connecting part formed at an end-face of one of the comer piece and a second side connecting part formed at an end-face of the other of the corner piece, the lower female connecting part of one corner type track configured to fit and mate with the male connecting part of the corner type track below and adjacent to such track, and each central type track having and elongated body with a front part forming an outer face of the building chamber and a back part forming an inner face of the building chamber, an upper male connecting part is formed along an upper edge of elongated body of the central type track, a lower female connecting part is formed along a lower edge of the elongated body of the central type track, a first side connecting part formed at a first side end of the elongated body and a second side connecting part formed at a second side end of the elongated body, the lower female connecting part of one of the central type track is configured to fit and mate with the male connecting part of the central type track below and adjacent to such track, the two side connecting parts of the central type tracks of the two central extendable walls configured to fit and mate with the respective first or second side connecting parts of the adjacent corner type tracks from the respective adjacent corner extendable wall.

4. The additive manufacturing system of claim 3, wherein the first and the second side connecting parts of each of the comer tracks comprise a back lip portion with a toothed end-face, and wherein the first and the second side connecting parts of each of the central type tracks comprises a side ledge and a toothed side end-face extending out of the side ledge, the back lip portion of the corner tracks side connecting parts is sized and shaped to fit and mate with the respective side connecting parts of the central track forming an angled chopped connecting face between the central track and the corner track.

5. The additive manufacturing system of claim 3, wherein the mounting structure comprises four linear guides and the supporting structure has four openings to receive at least partially second end of the four linear guides.

6. The additive manufacturing system of claim 1, further comprising a track pulling system configured to carry each of the at least two extendable chamber walls, the track pulling system comprises two or more pulling elements and a number of guiding elements configured to positioned and guide the two or more pulling elements, each or the two ormore pulling elements is operatively connected to the distal end of the respective extendable chamber wall and the support structure.

7. The additive manufacturing system of claim 3, wherein two rollers of the at least two rollers are central rollers configured to press against the respective central extendable walls and two rollers of the at least two rollers are corner rollers configured to press against the respective corner extendable walls, the space between the two central rollers and the base is smaller than the space between the corner rollers and the base.

8. The additive manufacturing system of claim 1, wherein the driver comprises an electrical motor and a mechanical linear actuator that is connected to the support structure.

9. The additive manufacturing system of claim 8, wherein the driver comprises a stepper motor with an endless belt, the linear actuator is a ballscrew actuator positioned in proximity to each linear guide of the mounting structure.

10. The additive manufacturing system of claim 8, wherein the driver lifts the at least two extendable chamber walls of the extendable build chamber in incremental steps, each step corresponding to the predetermined height of the powder layer.

11. The additive manufacturing system of claim 1, further comprising a control system preprogrammed to control the driver of the extendible build chamber, the powder dispensing system and the energy source, the control system comprising an input unit, an output unit, a processing unit and a memory unit with stored pre-programmed instructions.

12. The additive manufacturing system of claim 11, further comprising a milling system that comprises, a milling spindle, an automatic tool changer, a tool magazine that has brush tools and cutting tools and a driver configured to drive the milling spindle in X-direction along a X-linear guide, in Y-direction along an Y-linear guide and in Z-direction along a Z- linear guide, the control system in communication with the milling system to add brushing tools to remove remaining powder of a printed object and to add cutting tool to machine brushed printed object.

13. The additive manufacturing system of claim 11, further comprising a plurality of position measuring sensors to measure position of the frame of the extendible building chamber relative to the build plate, the position measuring sensors sending measured signals to the controller that is in communication with the driver of the extendible building chamber to adjust height of the extendible walls.

14. An extendable build chamber comprising: a build structure that comprises:• a base,• a mounting structure having two or more linear guides with a first end anchored in the base a second end opposite the first end,• a supporting structure mounted to the second end of the two or more linear guides, the supporting structure being movable up and down along the two or more linear guides,• a driver in communication with the supporting structure and configured to drive the supporting structure up and down along the two or more linear guides; a build plate defining a powder bed fixed to a top surface of the base; a frame of the an extendable building chamber mounted and secured to the supporting structure; at least two sets of plurality of interconnected tracks interconnected with two- part connectors formed along an upper edge, along a lower edge and at each side ends of each track to form the at least two extendable chamber walls; and at least two rollers connected to the base of the build structure in proximity to the build plate such that a space is created between the rollers and the top surface of the base, the distal end of each of the at least two extendable chamber walls passing through the space under respective roller such that the roller presses the respective extendable chamber wall towards and against a seal of the build plate to seal the building chamber, wherein when the driver moves the supporting structure upwards away from the base it moves upward the frame therefore raising upwards the at least two extendable chamber walls in a number of stepped positions between a first retracted position when the chamber wall is in a lowest retracted position towards a highest extended position when the chamber wall is at its highest extended position.

15. A powder dispensing system comprising: a powder feeder having:• a housing defining an inner cavity with an inlet and an outlet;• a dispensing nozzle comprising a plurality of spring arms arranged in an array, each spring arm having a first arm, a second arm spaced apart from the first arm forming a space therein between, a spring connected to a proximal end of first arm and a proximal end of the second arm, the spring of each of the first arm and the second arm of each spring arm in the array allow the first and second arms of one spring arm in the array of spring arms to move independently one from another as well as independently from the arms of the other spring arms in the array, the space formed between the first and second arms of each spring arm in the array of spring arms form a dispensing channel extending between the a proximal end and a distal end of the dispensing nozzle, a feeding head formed at the distal end of the dispensing nozzle; and a driver to provide vibration of the powder feeder and the dispensing nozzle to dispense the powder through the dispensing channel.

16. The powder dispensing system of claim 15, wherein each spring arm in the array of spring arms has unique harmonic frequency over their length depending on a stiffness of the spring connected to its proximal end.

17. The powder dispensing system of claim 15, wherein the feeding head oscillates due to oscillation of the nozzle and moves in small steps in Z directions by the spring at the proximal end of each of the first and second arms to level and compress the dispensed powder.

18. The powder dispensing system of claim 15, wherein the driver comprises a motor in communication with a rotating shaft mounted into an elongated opening formed in an upper part of the housing, two followers are mounted to the housing each having a head protruding into the shaft opening, the two followers being on an opposite side of the shaft opening, wherein the rotation of the cam-like shaft causes into vibration of the housing due to connection of the shaft with the two followers.

19. A method of manufacturing three-dimensionally shaped object using additive manufacturing system of claim 1 comprising steps of(i) forming a powder layer onto a powder bed formed on a build plate fixed to a base of an extendable building chamber of claim 14 using a powder dispensing system of claim 15;(ii) forming a solidified layer by irradiating the powder layer with an energy beam thereby melting or sintering the powder and subsequent solidification of the powder;(iii) driving the extendable stepped chamber wall to a next step of extended wall position and forming another solidified layer by newly forming a powder layer on the previously solidified layer and then irradiating the new powder layer with the energy beam, steps (i) to (iii) performed repeatedly;(iv) removing a remaining unsolidified powder of the solidified layer using a brush system; and(v) machining the brushed surface of a shaped object precursor obtained during manufacturing of the three-dimensionally shaped object.

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