FIELD OF INVENTION
[001]The present invention relates to a three dimensional printer. More specifically, the present invention relates to a fused deposition modeling based three dimensional printer.
BACKGROUND
[002]Three dimensional (3D) printing is a process of creating a 3D object with material being added layer by layer in three dimension formations. In the last couple of years, the applications of 3D printing have extended to developing mechanical components, medical components, confectionary items such as candies and chocolates, clothing, etc.
[003] Currently, there are two 3D techniques predominantly used for manufacturing 3D objects: Stereo lithography (SLA) and Fused Deposition Modelling (FDM). SLA uses photopolymerization (especially Ultra-Violet light) for producing 3D objects. On the other hand, FDM extrudes semi-liquid plastic in a required layout to create 3D objects. FDM based 3D printers currently in use include an extrusion assembly which extrudes small beads or streams of material. The heated material then passes through a nozzle and hardens immediately on a bed disposed below to form a 3D object.
[004] FDM technology employs simpler inventory and hence, has facilitated fast growth of various industries by reducing the cost of manufacturing, reducing build time, reducing weight of the 3D object, reduction of waste compared to conventional processes, etc.However, the conventional FDM based 3D printers do offer various disadvantages.
[005] For example, the movement of the bed present in conventional FDM based 3D printersis mostly performed with a single motor. This causes deflection and hanging of the bed, hence, reducing the quality of the 3D object. Further, constant hanging of the bed may require intermittent manual intervention to

stabilize the bedthereby reducing the level of automation in such systems. Further, the extruder assembly in conventional systems is generally heavy which requires more motor power and hence makes the printer cost intensive. Moreover, the conventional systems commonly employ either Delta or Cartesian methods for movement of the bed and/or extrusion assembly. Such methods have reduced efficiency as they are less accurate, less stable and slow.
SUMMARY
[006] The present invention discloses a three-dimensional printer. The printer includes a frame, a feeding mechanism supporting a polymer filament and a driving mechanism fixed on the frame. The driving mechanism is stationary. The printer also includes an extruder assembly coupled to the feeding mechanism and the driving mechanism.The extruder assembly is configured to move along X axis and/or Y axis.The extruder assembly includes a nozzle, a gear and pulley arrangement and a first heating element.The gear and pulley arrangement maintains tension in the polymer filament.
[007] The printer also includes a plate having a second heating element and is provided within the frame.The plate is configured to move along Z axis. The printer further includes a controller coupled to the driving mechanism.The controller configures the driving mechanism to facilitate movement of one of the extruder assembly and the plate.
BRIEF DESCRIPTION OF DRAWINGS
[008] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.

[009] FIG.l & la depicts a schematic view of a 3D printer in accordance with an embodiment of the present invention.
[0010] FIG. lb illustrates the extruder assembly 30 of FIG. 1 in accordance with an embodiment of the present invention.
[0011] FIG. lc illustrates the platform 40 of FIG. 1 in accordance with an embodiment of the present invention.
[0012] FIG. 2 depicts an exemplary flowchart of the working of the 3D printer 100 in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF DRAWINGS
[0013] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[0014] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional

details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[0015] The present invention discloses a FDM based 3D printer which converts an illustration into a 3D object.The FDM based 3D printer extrudes a semi-liquid polymerfilament in a required layout to create objects. The object is createdby depositing semi-liquid polymer througha heated nozzle to build a layer that instantly hardens. Subsequently, a next layer is laid over the previous layer and this process is repeated until the 3D object is created.
[0016] The FDM based 3D printer of the present invention is software aided system. In order to create the 3D object, the illustration is first embodied in software installed on an electronic device. Subsequently, a model is created with the help of software for example, a computer aided design (CAD) software. The model is further converted into a standard format such as Stereo-lithographic file (.STL file), a Virtual Reality Modeling Language (VRML) file, etc. The said file of the model is for example, a mesh, or series of triangles oriented in space. The model encloses a 3D volume. The file represents a part of the surface of a 3D model that is then used for implementing slicing algorithm. The file slices the model into thin cross-sectional layers based on which layers are laid to print the object.
[0017] The FDM based 3D printer is a compact and a light weight assembly. In an embodiment, the FDM based 3D printer is implemented using a positioning system, say, CoreXY as its method of motion.Further, the said motion is driven by a driving mechanism for example, stepper motors. In an embodiment, the stepper motors used in the FDM based 3D printer are stationary motors.The utilization of the above described CoreXY in the present invention and stationary motors enhance the accuracy of the FDM based 3D printer, increase the speed of

printing and significantly reduce the chances of wobbling of the platform of the FDM based 3D printer.
[0018] Now referring to figures, FIG. 1 illustrates an exemplary architecture of the 3D printer 100. In an embodiment, the 3D printer 100 is a modular assembly 5 which may be easily assembled and dissembled.
[0019] As shown in FIG. 1, the 3D printer 100 includes an enclosure 10, a frame 20, an extruder assembly 30, a platform 40 and a controller 50. The said components of the 3D printer 100 operate in a synchronized manner to 3D print the object.
10 [0020] The enclosure 10 is a compact body which fully encloses various
components of the 3D printer 100. In a preferred embodiment, the enclosure 10 is constructed using a durable material such as a metal or a polymer. For example, thepolymer is acrylic. In an embodiment, the enclosure 10 is an arc resistant body and thus provides safety to the operator.
15 [0021] The enclosure 10 may include predefined dimensions and shape to accommodate 3D objects.In an embodiment, the enclosure 10 includes a plurality of walls which form a rectangular box type structure as shown in FIG. 1. In an embodiment, the walls of the enclosure 10 include at least a transparent portion. For example, the walls may include a glass window to help the user
20 visualize/monitor the formation of the 3D object.
[0022] The walls of the enclosure 10 are supported by the frame 20 of the 3D printer 100.The frame 20 acts as a structural framework for
supporting/mounting the components of the 3D printer 100 such as, without limitation, the extruder assembly 30, the platform 40, etc.
25 [0023] The frame 20 includes a plurality of support bars 20a which are
connected together to form the frame 20. The support bars 20a are stiff and rigid which may be made of a sturdy and durable material. The materials may include
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metals and/or polymers such as steel, aluminum, etc. In an embodiment, aluminum T slot angle extrusion is used for constructing the support bars 20a.
[0024] The frame 20 of the 3D printer defines a top end 20b, bottom end20c, and two pairs of oppositely facing sides 20d, 20e.
5 [0025] The extruder assembly 30 is mounted over an anchor 30a which is
disposed over the top end 20a of the frame 20. As shown in FIG. 1, the anchor 30a rests over the support bars 20. The support bars 20 may be provided with linear rails which allow the movement of the anchor 30a. The extruder assembly 30 is provided over the anchor 30a facing downwards towards the bottom end 10 20b of the frame 20.The extruder assembly 30 is slidably coupled to the anchor 30a with the help of for example, a linear rail and block system.
[0026] In an embodiment, there are two extruder assemblies 30 for 3D printing multi-coloured objects.
[0027] The extruder assembly 30 of the present invention is a lightweight 15 assembly which significantly reduces the motor power required for its movement, thereby rendering the 3D printer 100 cost effective.
[0028] The extruder assembly 30 may be programmed to move along an X-axis and a Y-axis by a positioning system (not shown). In an embodiment, the positioning system is CoreXY. For example, the extruder assembly 30 may slide 20 over the anchor 30a to move along the X-axis. In an embodiment, the extruder assembly 30slides along the Y-axis on movement of the anchor 30a over the support bars 20a.The movement of the extruder assembly 40 is driven by a driving mechanism. In an embodiment, two stationary stepper motors 30b drive the movement of the extruder assembly 30.
25 [0029] As illustrated in FIG. 1b, the extruder assembly 30 of the present
invention includes a first heating element 30c and a nozzle 30d. The extruder assembly 30 receives a polymer filament. The polymer used may include without
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limitation, acrylonitrile butadiene styrene (ABS), poly-lactic acid or poly-lactide (PLA), polyvinyl alcohol (PVA), thermoplastic elastomer (TPE), etc.
[0030] The first heating element 30c of the extruder assembly 30 melts the polymer filament. In an embodiment, in order to create a 3D object, the extruder 5 assembly 30 provides droplets of the semi-liquid polymer through the nozzle 30d on a plate placed over the platform 40. In an embodiment, PLA is extruded at a first predefined temperature of 170- 220°C.
[0031] The extruder assembly 30 also includes a gear and pulley mechanism 30e. The polymer filament is fed to the gear and pulley mechanism 30eof the 10 extruder assembly 30 from a feeding mechanism 60. The gear and pulley mechanism 30e in the present invention maintains tension in the polymer filament.
[0032] As represented in FIG. 1, the feeding mechanism 60 includes a polymer filament roll 60awhich is placed over at least two supports 60b. The feeding
15 mechanism 60 may be mounted on the 3D printer 100 and a loose end of the
filament may be fixed to the extruder assembly 30. The feeding mechanism60a continuously feeds the extruder assembly 30 with the filament. The feeding mechanism 60 eliminates the need of any powered driving mechanism for example a motor or manual intervention for continuously providing the filament
20 to the extruder assembly 30.
[0033] As represented in Fig. 1c, the platform 40 may include a plate 40a. In an embodiment, the plate 40a is disposed in the middle of the platform 40. The plate 40a acts as a base to receive the semi-liquid polymer. In an embodiment, the semi-liquid polymer instantly hardens once it contacts the plate 40a. The 25 plate 40a may be made of a material, for example, glass or aluminum. The plate 40a is maintained at a second predefined temperature between 50-70°C. In an embodiment, a second heating element is disposed underneath the plate 40a for heating and maintaining the temperature of the plate 40a.
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[0034] The platform 40 may be positioned below the extruder assembly 30 with the help of mounting rods 40b. In an embodiment as represented in FIG. 1, three mounting rods 40b on each side 20c are disposed to mount the platform 40. Each of the three mounting rods 40b may include one threaded rod b1 and two 5 smooth rods b2. The threaded rods b1 act as lead screws and help the platform 40 to slide over them. Each threaded rod b1 is coupled to a driving mechanism for example, a stationary stepper motor (not shown).The smooth rods b2 act as supports for mounting the platform 40.
[0035] The platform 40 may be movable in one or more of the X, Y, and Z axes in 10 order to aid in the formation of the 3D object. In an embodiment, the platform 40 is moved along the Z axis on the mounting rods 40b by the positioning system. In an embodiment, the movement of the platform 40 is driven by two stepper motors, one stepper motor on each side 20c of the frame 20.
[0036] The movement of the extruder assembly 30 while the semi-liquid 15 polymer is being dropped on the plate 40a may result in formation of a first lyer of the 3D object. Once, the first layer is laid over the plate 40a, the platform 40 moves downwards. In an embodiment, the platform 40 moves 100-300 µm downwards after each layer is laid. Additional layers of the polymer may then be deposited layer by layer to eventually create a complete 3D object.
20 [0037] In an exemplary embodiment, the extruder assembly 30 of the 3D printer 100 is configured to move along X axis and Y axis with the help of two stationary stepper motors 30b. In an embodiment, the stepper motors 30b operate in tandem to reach a particular position having a predefined X and Y coordinates. In an embodiment, the movement along Z axis is controlled by two stepper motors
25 which move the platform 40 laterally (up and down). The aforesaid movement of the extruder assembly 30 and the platform 40 is mediated by CoreXY. The CoreXY mediated motion of the extruder assembly 30 and/or the platform 40 enhances the accuracy of the 3D printer 100, increases the speed of printing
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and/or significantly reduces the chances of wobbling of the platform 40 of the 3D printer 100.
[0038] The movement of extruder assembly 30 and/orthe platform 40 may be directed by an electronic device, for example, a computer (not shown) with 5 which the 3D printer 100 is in communication (either wired or wirelessly). The electronic device may be installed with software which directs the movements through a digital model of the 3D object to be printed. The digital model may be a 3D information file describing the 3D printable object in three dimensions. The details of the 3D object to be laid, for example, the dimensions of the object may 10 be manually fed to the electronic device initially before the printing is initiated.
[0039] The controller 50 may be electrically or otherwise coupled in a communicating relationship with without limitation, the driving mechanism of the extruder assembly 30 and the platform 40, and other components of the 3D printer 100. In an embodiment, the controller 50 is coupled to the driving 15 mechanism via a wired connection. In general, the controller 50 is operable to
control the components of the 3D printer 100 in order to fabricate the printing of the 3D object.
[0040] The controller 50 may include any combination of software and/or processing circuitry suitable for controlling the various components of the 3D 20 printer 100 such as without limitation, microprocessors, microcontrollers,
application-specific integrated circuits, programmable gate arrays, and any other digital and/or analog components, as well as combinations of the foregoing, along with inputs and outputs for transceiving control signals, drive signals, power signals, sensor signals, and so forth.
25 [0041] In an embodiment, thecontroller 50 associated with the electronic device coupled to the printer 100, e.g., through a wired or wireless connection.
[0042] FIG. 2 depicts an exemplary flowchart of the working of the 3D printer 100. At step 201, the illustration of the 3D object to be printed is converted into
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a 3D file depicting a 3D model with the help of software installed on the electronic device. The said file is, for example, a mesh, or series of triangles oriented in space. The 3D model encloses a 3D volume. The file then sliced to create thin cross-sectional layers based on which a plurality of layers are laid to 5 print the 3D object.
[0043] Further, the user may also input the details of the 3D object to be printed for example, color of the 3D object, dimensions of the 3D object to be printed, etc. The filament roller 30e is loaded onto the 3D printer 100.
[0044] Once the 3D file is created, the 3D printer 100 is switched on and the 10 controller 50 activates the second heating element of the platform 40 at step
203.The second heating element is heats the plate 40a to the second predefined temperature ranging between 50-70°C.
[0045] At step 205, the controller 50 activates the firstheating element 30c of the extruder assembly 30. The first heating element 30c of the extruder 15 assembly 30 is heated at the first predefined temperature ranging between 170-220°C. The first heating element 30c extrudes the polymer filament.
[0046] At step 207, the controller 50 activates the stepper motors 30b and the gear and pulley system. The extruder assembly 30 is moved along the X and/or Y axis in order to lay a first layer of the 3D object. The nozzle 30 of the extruder 20 assembly 30 dispenses the semi-liquid polymer onto the plate 40a as per the movement of the extruder assembly 30.
[0047] At step 209, post the formation of first layer, the controller 50 activates the stepper motors to move the platform 40 downwards by 100-300 µm along the Z-axis.
25 [0048] Thereafter, step 207 is repeated and a second layer is laid over the first layer. The steps 207-209 are repeated till the 3D object is created at step 211.
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[0049] The 3D object printed by the 3D printer 100 may optionally undergo finishing process. The finishing process may involve, without limitation, sanding, lacquering, painting, etc.
[0050] The foregoing description of preferred embodiments of the present disclosure provides illustration and description, but is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the disclosure.
[0051] No element, act, or instruction used in the description of the present disclosure should be construed as critical or essential to the invention unless explicitly described as such. Also, as used herein, the article "a" is intended to include one or more items. Where only one item is intended, the term "one" or similar language is used.

We Claim:
A three-dimensional printer comprising:
a frame;
a feeding mechanism supporting a polymer filament;
a driving mechanism fixed on the frame, wherein the driving mechanism is stationary;
an extruder assembly coupled to the feeding mechanism and the driving mechanism, the extruder assembly being configured to move along X axis and/or Y axis, the extruder assembly includes
a nozzle;
a gear and pulley arrangement, the gear and pulley arrangement maintains tension in the polymer filament; and
a first heating element;
a plate having a second heating element and being provided within the frame, the plate being configured to move along Z axis;and
a controller coupled to the driving mechanism, wherein the controller configures the driving mechanism to facilitate movement of one of the extruder assembly and the plate.
The three-dimensional printer as claimed in claim 1 wherein the feeding mechanism comprises a filament roll and at least two supports.
The three-dimensional printer as claimed in claim 1 wherein the driving mechanism comprises a plurality of motors.
The three-dimensional printer as claimed in claim 1 wherein the gear and pulley arrangement is coupled to the polymer filament.

The three-dimensional printer as claimed in claim 1 wherein the controller configures the first heating element and the second heating element.
The method of operating a three-dimensional printer, the method comprising:
a. providing a sliced three dimensional filed with a plurality of thin cross-
sections;
b. maintaining a plate at a predefined temperature;
c. extruding a polymer filament at a first predefined temperature;
d. activating a gear and pulley system to maintain tension in the polymer
filament;
e. activating a driving mechanism of an extruder assembly to form a first
layer corresponding to one of the plurality of thin cross sections; and
f. activating a driving mechanism of a plate to move the plate downwards
by a predefined distance
repeating the steps e-f to obtain a three-dimensional object.