DESC:FIELD OF INVENTION
[0001] The embodiments of the present disclosure generally relate to an apparatus for three-dimensional (3D) printers, particularly to a field of polymer 3D printing. More particularly, the present disclosure relates to an apparatus for polymer 3D printing having a cable-actuated flexible arm for dispensing photosensitive polymeric material that is economical, low in weight and complexity, and adaptable to rapid prototyping.

BACKGROUND OF THE INVENTION
[0002] The following description of the related art is intended to provide background information pertaining to the field of the disclosure. This section may include certain aspects of the art that may be related to various features of the present disclosure. However, it should be appreciated that this section is used only to enhance the understanding of the reader with respect to the present disclosure, and not as admission of the prior art.
[0003] Three-dimensional (3D) printing technologies have revolutionized engineering design and manufacturing in recent decades. This has been possible, in part, due to the rapid development of printing-technology-specific devices. The most ubiquitous among 3D printing technologies are fused deposition modeling (FDM). Herein, molten polymer filament is deposited in a layer-wise manner. FDM printers commonly adopt a Cartesian or a delta robot design to position a material dispensing nozzle in a programmable manner. Cartesian printers commonly use a combination of three linear stages, where a pair of stages are utilized for positioning the material dispensing nozzle relative to a printing bed. A third stage adjusts the height of the printing bed relative to the material dispensing nozzle. In comparison, delta 3D printers use a system of linkages and joints to position the material dispensing nozzle. The cost and complexity of FDM 3D printers are dominated by factors related to fabrication, assembly, and control of the material dispensing system.
[0004] A second class of 3D printing technology, labeled stereolithography (SLA) printers, use a photosensitive polymer material, henceforth referred to as a resin. Such materials undergo a polymerization reaction when exposed to light in a specific range of wavelengths (typically in the ultraviolet regime), causing the material to change phase from a liquid to a solid. A technology closely related to SLA printing is digital light-projection printers (DLP). The liquid polymer is stored in a vat and is exposed to projected light at a controlled depth, causing a thin layer of the resin to cure. The vat is gradually raised/lowered, thereby curing the resin layer-by-layer, eventually realizing a free-form solidified shape.
[0005] The FDM printers form layers by depositing lines of molten material where a resolution is defined by the size of the nozzle. Further, voids may be observed as the nozzle deposits various layers of molten material. As a result, layers may not fully adhere to one another and may not cover the required intricate details while printing. The SLA printers are commonly used to create smaller objects, are slower, and are more expensive compared to FDM printers.
[0006] In US20140265034A1, the printer apparatus disclosed has a build platform that rotates in a spiral manner and is raised to receive the deposit of material for 3D printing. However, the mentioned system is more complex in nature with additional mechanisms for rotating the printing bed in a synchronous manner as the printing head. In US7291002B2, the disclosed apparatus is used for 3D printing but has multiple printing heads and also includes multiple build tables, which can lead to complications in 3D printing of objects due to added complexity in creation of objects.
[0007] There is, therefore, a need in the art to provide a system that provides a direct mechanism for printing of 3D objects in a simplistic manner.

OBJECTS OF THE INVENTION
[0008] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are listed herein below.
[0009] It is an object of the present disclosure to provide a three-dimensional (3D) printer apparatus with a cable-actuated flexible arm to dispense and cure photosensitive polymeric materials.
[0010] It is another object of the present disclosure to provide the cable-actuated flexible arm that positions a print head accurately and programmatically during printing.
[0011] It is another object of the present disclosure to provide the print head with a nozzle to dispense a photosensitive polymetric material and an array of light sources to cure the material when it is dispensed from the nozzle for 3D printing.
[0012] It is yet another object of the present disclosure to provide the 3D printer apparatus with the cable-actuated flexible arm that provides multiple degrees of freedom to the print head, thereby enabling an accurate movement of the print head as a function of time.
[0013] It is yet another object of the present disclosure to provide the 3D printer apparatus with the cable-actuated flexible arm that utilizes a curing mechanism that polymerizes the photosensitive polymeric material instantaneously.
[0014] It is another object of the present disclosure to provide the 3D printer apparatus that dispenses resin rather than a molten filament, cures material locally using a moving light source positioned alongside a material dispensing system.
[0015] It is yet another object of the present disclosure to provide the 3D printer apparatus that minimizes cost and complexity, and may be specially customized for in-situ manufacturing in low-gravity space applications.

SUMMARY
[0016] Within the scope of this application, it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
[0017] In an aspect of the present disclosure, the apparatus is a 3D printer comprising a flexible arm detachably coupled to a print platform, a print head at one end of the arm, operated by cables and motors to position the print head relative to the print platform.
[0018] In an aspect of the present disclosure, the print head includes a resin dispensing nozzle and a curing system composed of an array of light sources.
[0019] In an aspect of the present disclosure, the method for 3D printing involves supplying resin from a reservoir to a resin dispensing nozzle via a conduit. The resin is then discharged from the nozzle within the field of view of the array of light sources directed towards a printing bed, where the bed's axis is perpendicular to the motion plane of the nozzle. The resin dispensing nozzle is capable of delivering the resin precisely to the desired locations without forming voids, air bubbles or interruptions in the flow of the material.
[0020] Various objects, features, aspects, and advantages of the inventive
subject matter will become apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0021] The accompanying drawings, which are incorporated herein, and constitute a part of this disclosure, illustrate exemplary embodiments of the disclosed methods and systems which like reference numerals refer to the same parts throughout the different drawings. Components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Some drawings may indicate the components using block diagrams and may not represent the internal circuitry of each component. It will be appreciated by those skilled in the art that disclosure of such drawings includes the disclosure of electrical components, electronic components, or circuitry commonly used to implement such components.
[0022] FIG. 1 illustrates an exemplary representation 100 of a proposed three-dimensional (3D) printer with a cable-actuated flexible arm, in accordance with an embodiment of the present disclosure.
[0023] FIG. 2 illustrates an exemplary print head consisting of a resin dispenser and curing system of the 3D printer, in accordance with an embodiment of the present disclosure.
[0024] FIG. 3 illustrates an exemplary block diagram of a proposed system for controlling the cable-actuated flexible arm, in accordance with an embodiment of the present disclosure.
[0025] FIG. 4 illustrates an exemplary flow diagram of a method 400 for implementing the 3D printer with the cable-actuated flexible arm, in accordance with an embodiment of the present disclosure.
[0026] FIG. 5 illustrates exemplary illustrations of printed objects by the apparatus, in accordance with an embodiment of the present disclosure.
[0027] The foregoing shall be more apparent from the following more detailed description of the disclosure.

BRIEF DESCRIPTION OF THE INVENTION
[0028] In the following description, for explanation, various specific details are outlined in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent, however, that embodiments of the present disclosure may be practiced without these specific details. Several features described hereafter can each be used independently of one another or with any combination of other features. An individual feature may not address all of the problems discussed above or might address only some of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein.
[0029] The ensuing description provides exemplary embodiments only and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the disclosure as set forth.
[0030] Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail to avoid obscuring the embodiments.
[0031] Also, it is noted that individual embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed but could have additional steps not included in a figure. A process may correspond to a method 400, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.
[0032] The word “exemplary” and/or “demonstrative” is used herein to mean serving as an example, instance, or illustration. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. In addition, any aspect or design described herein as “exemplary” and/or “demonstrative” is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it meant to preclude equivalent exemplary structures and techniques known to those of ordinary skill in the art. Furthermore, to the extent that the terms “includes,” “has,” “contains,” and other similar words are used in either the detailed description or the claims, such terms are intended to be inclusive like the term “comprising” as an open transition word without precluding any additional or other elements.
[0033] Reference throughout this specification to “one embodiment” or “an embodiment” or “an instance” or “one instance” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0034] The terminology used herein is to describe particular embodiments only and is not intended to be limiting the disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any combinations of one or more of the associated listed items.
[0035] Certain terms and phrases have been used throughout the disclosure and will have the following meanings in the context of the ongoing disclosure. For example, the term “resin” may refer to a solid or liquid synthetic organic polymer. Resin may include a light reactive thermoset. When resins are exposed to certain wavelengths of light, short molecular chains may join together polymerizing monomers and oligomers into a rigid or a flexible geometry. The term “three-dimensional (3D) printer may refer to an apparatus that creates a physical prototype from a 3D digital model by laying thin layers of a material consecutively.
[0036] The various embodiments throughout the disclosure will be explained in more detail with reference to FIGs. 1-4.
[0037] FIG. 1 illustrates an exemplary representation 100 of a proposed three-dimensional (3D) printer with a cable-actuated flexible arm, in accordance with an embodiment of the present disclosure.
[0038] As illustrated in FIG. 1, the cable-actuated flexible arm 102 may be the key functional element of the 3D printer assembly 100.
[0039] In an embodiment, the flexible arm 102 may be a beam with a prismatic cross-section having a thickness much smaller than the width or length of the flexible arm 102. As shown, the flexible arm 102 may be connected with a printing bed 120 (or interchangeably referred to as print platform 120) via a clamp 102-A. It may be appreciated that the flexible arm 102 may be interchangeably referred as a cable-actuated flexible arm 102 throughout the disclosure. In an embodiment, the flexible arm 102 may be composed of a polymer or a metal, but not limited to the like, and remain elastic during operation. Due to its slenderness, the flexible arm 102 may respond to loading with large deflections, while the strains remain sufficiently small to prevent irreversible material damage.
[0040] Referring to FIG. 1, the flexible arm 102 may be actuated using two or more cables (104-A, 104-B) attached along its length. In an embodiment, the flexible arm 102 may be actuated to position a nozzle (not shown in FIG. 1) at a particular point in a plane to enable 3D printing via a print head configured with a nozzle. Each cable (104-A, 104-B) may be routed through a fixed post to a spool mounted on a motor shaft. In an embodiment, the lengths of the cables (104-A, 104-B), and in turn their tensions, may be controlled using a plurality of motors (110-A, 110-B) as shown in FIG. 1. Further, one or more routing points (122-A, 122-B) may be used to connect the cables (104-A, 104-B) to the motors (110-A, 110-B). The cables (104-A, 104-B) may be inextensible in tension and may slacken in compression. In an embodiment, the cables (104-A, 104-B) may enable movement of the print head in a plane, where the print head may be supported by the flexible arm 102 and provide two degrees of freedom during 3D printing.
[0041] In an embodiment, the flexible arm 102 may be detachably coupled to the 3D printer assembly/apparatus at one end and a print head comprising of a resin dispensing nozzle and a curing system at the other end. The curing system may comprise an array of light sources (not shown in FIG. 1). The curing system may be connected to a resin reservoir 112 via a conduit 118. The cables (104-A, 104-B) may be operably coupled to the arm supporting the nozzle and curing system, and operated via the motors (110-A, 110-B). The motors may operate the cables (104-A, 104-B) and may cause the cables (104-A, 104-B) to actuate the arm to position the nozzle and curing system in a plurality of locations and orientations, to enable the disposal of the resin via the nozzle.
[0042] In an embodiment, the resin dispensing nozzle may not be limited to dispense a resin material only. The materials can include but not limited to water-based, acrylic-based or epoxy-based resins. Resin material may include standard resin, engineering resin, flexible resin, and castable resin.
[0043] In an embodiment, the deflection of the flexible arm 102 may be controlled through the cables (104-A, 104-B). Specifically, as each of the motors (110-A, 110-B) spin, the motors (110-A, 110-B) reel in or reel out the cables (104-A, 104-B) attached to it, thereby loading the flexible arm 102 by a force, where the magnitude of the force on the flexible arm 102 equals the tension in the cables (104-A, 104-B). In an embodiment, the direction of the force on the flexible arm 102 may be oriented along the line joining the routing points (122-A, 122-B) with the point of attachment of the cables (104-A, 104-B) on the flexible arm 102. In an embodiment, a mechanical theory may be used to determine the relationship between the forces exerted by the cables (104-A, 104-B) on the flexible arm 102 and the resultant deflection of the flexible arm 102. Accurate knowledge of this relationship may enable the determination of the cable tensions, and in turn, the motor actuation required to position the tip of the flexible arm 102 at a desired location in its plane of motion.
[0044] In an embodiment, the motors (110-A, 110-B) operating the cables (104-A, 104-B) may be controlled via a processor (not shown in FIG. 1), where the processor may be configured with an algorithm or technique to accurately control the printing in the plane of motion of the nozzle and enable a high positional accuracy. Therefore, the cables (104-A, 104-B) may perform synchronously to enable the high positional accuracy of the tip.
[0045] In an embodiment, the cables (104-A, 104-B) can be high-strength, low-stretch cables made of materials such as steel or Kevlar, ensuring precise and reliable actuation of the flexible arm. Each cable can be attached to a motor (110-A, 110-B) with high-resolution encoders for accurate position feedback and closed-loop control of the arm's movements. Advanced motion planning algorithms optimize cable tension and actuation sequences can minimize vibration in the flexible arm 102 and improve print accuracy.
[0046] In an embodiment, a resin module in the 3D printing assembly 100 may include, but not be limited to, the resin reservoir 112, the nozzle, and the array of light sources to cure the resin.
[0047] In an embodiment, the array of light sources may include, but not be limited to, a multitude of light emitting diode (LED) light sources.
[0048] In an embodiment, the material dispenser may ensure a consistent supply of resin to the dispensing nozzle throughout the printing process, maintaining a steady flow of material for accurate and reliable printing.
[0049] Referring to FIG. 1, the resin reservoir 112 may be a pressurized chamber that dispenses the resin at a constant flow rate. Resin may be conveyed from a reservoir outlet to the nozzle through a lightweight, flexible conduit 118. The flow of resin in the conduit 118 may be controlled via a solenoid valve 118-A. The resin reservoir 112 holds the liquid resin used for 3D printing, and maintains a consistent pressure throughout the printing process. By keeping the pressure constant within the reservoir, the flow rate of resin through the dispensing system remains stable. The stability ensures a consistent and predictable flow of resin to the printing nozzle, which is crucial for achieving uniformity and accuracy in the printed object.
[0050] The resin discharged at the nozzle and falling within the field of view of the array of light sources may undergo a polymerization reaction/curing and solidify as a result. While the resin reservoir 112 may be stationary, the nozzle and the array of light sources may be mounted on the tip of the flexible arm 102 and move with the flexible arm 102 during operation of the 3D printer.
[0051] In an embodiment, the array of light sources can consist of high-intensity UV LEDs arranged in a grid pattern to provide uniform and efficient curing of the printed resin. The array of light sources can include an adjustable intensity, which allows precise tuning of the curing energy, optimizing print speed and resin curing properties. Real-time monitoring and feedback mechanisms can ensure consistent curing conditions throughout the printing process, preventing under-cured or over-cured areas in the printed object.
[0052] In an embodiment, the resin reservoir 112 may include a plurality of nozzles to enable an inlet of air into the reservoir 112. The air pressure inside the resin reservoir 112 may enable the resin to be supplied to the nozzle via the conduit 118.
[0053] In an embodiment, the printing bed 120 may be mounted on a linear stage 122 whose axis may be orthogonal to the plane of motion of the nozzle. Further, the printing bed 120 may be coated with a material that adheres well with the printed resin.
[0054] The print platform 120 can also incorporate a removable build surface with options for different materials or surface treatments to accommodate various printing requirements.
[0055] In an embodiment, the array of light sources may be configured to illuminate the resin and cause the polymerization reaction, while eclipsing the tip of the flexible arm 102. Further, the intensity of the array of light sources closer to the tip of the flexible arm 102 may dip to form a dark region surrounded by an annular illuminated region.
[0056] Conventionally, 3D printers print on a print bed that moves in the direction of gravity. In an embodiment, the present disclosure may enable the resin module and the flexible arm 102 to perform independently of gravity. In an embodiment, the 3D printer, as depicted in FIG. 1 with the flexible arm 102, may be configured to be independent of gravity and print in arbitrary orientations. Hence, the 3D printer with the flexible arm 102 may be configured to print in a vertical plane specialized for low-gravity space applications.
[0057] In an embodiment, the print bed 120 may be rotated about its translation axis. Since the print head’s motion spans the print bed’s 120 plane, rotation of the print bed 120 is redundant. Nevertheless, the print bed rotation 120 continuously alters the gravity head of the resin as the nozzle dispenses it, which reduces gravity-influenced resin flow, especially when printing with resins having low viscosities of the resin.
[0058] In an exemplary embodiment, the flexible arm 102 may incorporate orientation control via a plurality of secondary cables configured to control the tip of the nozzle.
[0059] In an embodiment, the construction of the flexible arm 102 may include multiple geometries and variable cross-sections to be suited for space and non-space applications. Further, the flexible arm 102 may incorporate varying degrees of flexibility and rigidity to compensate for the weight of the nozzle and the array of light sources.
[0060] In an embodiment, the flexible arm 102 can be composed of a lightweight yet durable material, including polymers and metals, to ensure precise and smooth movements during printing. The flexible arm 102 may incorporate internal channels or conduits to route the cables (104-A, 104-B) and resin delivery tubes, ensuring tidy and efficient cable management.
[0061] In an embodiment, the ejection of the resin may be orthogonal to the direction of gravity and the curing mechanism may be instantaneous as a function of time to enable the solidification of the resin. Hence, the flexible arm 102 with the cable actuation may be suited for space applications.
[0062] In an embodiment, the following steps may be utilized as per the functionality of the 3D printer with the flexible arm 102.
[0063] The process may include slicing, where a given model may be sliced layer-wise along the direction of translation of the printing bed 120 using non-proprietary techniques utilizing open-source software libraries. Each slice may be processed by an algorithm to define the trajectory for the material dispensing nozzle. The slicing operation may also determine the motion of the printing bed 120 as the nozzle transitions from printing one slice to the next.
[0064] Further, the process may include precomputing cable actuation, where the nozzle trajectories may be defined by the slicing technique with a prescribed sequential motion for the tip of the flexible arm 102. Additionally, the motor actuation required to control the cable tensions may be computed by a processor so that the tip of the flexible arm 102 may follow the desired trajectory.
[0065] Furthermore, the process may include layer-wise printing where the motors (110-A, 110-B) reeling the cables (104-A, 104-B), the linear stage 122 supporting the printing bed 120, and the array of light sources may be operated concurrently as preplanned using an electronic computing device. The tip of the flexible arm 102 may move at a constant speed and the resin may flow through the nozzle at a constant rate while maintaining a small liquid bridge between an exit orifice of the nozzle and a substrate. This ensures that the resin is deposited at a constant rate (i.e. mass and volume). The resin dispensed at the nozzle may be cured by the light incident from the array of light sources. Further, the nozzle may traverse the preplanned path layer by layer depositing the resin as it moves.
[0066] In an embodiment, a workspace of the flexible arm 102 is the region of the print bed 120 accessible by its tip. Although numerous factors govern the extent of the workspace, the most significant one, namely, the slack condition is the locus of the tip in the limiting case when one of the cables is slack, i.e., either T1 = 0, T2 > 0 or T1 > 0, T2 = 0 (T = Tension). In such a scenario, the arm is effectively actuated by a single cable (either 104-A or 104-B). The printhead can follow nontrivial trajectories in each case. A critical limit on the workspace can imposed by the torque rating of the motors (110-A, 110-B), which restricts the tensions in the cables (104-A, 104-B) during operation. Similarly, it is desirable to limit the elastic strain in the arm to ensure durability. Detailed examinations of the factors may require mechanical modelling and simulations.
[0067] FIG. 2 illustrates an exemplary resin dispenser and curing system 200 of the 3D printer, in accordance with an embodiment of the present disclosure. An ordinary person skilled in the art may understand that the flexible arm, tip, resin, dispensing nozzle, and printing bed referred to with the description of FIG. 2 may be similar to the flexible arm 102, tip, resin, nozzle, and printing bed 120 of FIG. 1, respectively, in functionality.
[0068] As illustrated in FIG. 2, a dispensing nozzle 202 may be encased in a conical sleeve 204 carrying an array of light sources 206 that illuminate the resin deposited by the dispensing nozzle 202. An inner seam 208 may shield the liquid bridge formed between the dispensing nozzle 202 and the substrate.
[0069] In an embodiment, the resin may be disposed via a needle configured in the tip of the flexible arm 102, where the array of light sources 206 may create a annular illumination around the tip of the flexible arm 102. The array of light sources 206 may cure the resin, where some part of the resin may fall within a field of view of the array of light sources 206 irrespective of orientation. The printing bed 120 may move continuously in a direction where the thickness of the resin is required to grow. Further, the printing bed 120 may move in an orthogonal direction compare to the tip of the flexible arm 102.
[0070] In an embodiment, the 3D printer with the flexible arm 102 and a material dispensing curing system 200 may be designed such that the resin may be dispensed by the tip of the flexible arm 102, but a liquid bridge between the dispensing nozzle 202 and the substrate may be unaffected. This may be achieved by designing the array of light sources to project an annular field of illumination, which may keep the liquid bridge shielded and, therefore un-polymerized.
[0071] FIG. 3 illustrates an exemplary block diagram 300 of a proposed system 302 for controlling the cable-actuated flexible arm in the 3D printing assembly, in accordance with an embodiment of the present disclosure.
[0072] Referring to FIG. 3, the system 302 may include one or more processor(s) 304. The one or more processor(s) 304 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that process data based on operational instructions. Among other capabilities, the one or more processor(s) 304 may be configured to fetch and execute computer-readable instructions stored in a memory 306 of the system 302. The memory 306 may be configured to store one or more computer-readable instructions or routines in a non-transitory computer readable storage medium, which may be fetched and executed to create or share data packets over a network service. The memory 306 may comprise any non-transitory storage device including, for example, volatile memory such as random-access memory (RAM), or non-volatile memory such as erasable programmable read only memory (EPROM), flash memory, and the like.
[0073] In an embodiment, the system 302 may include an interface(s) 308. The interface(s) 308 may comprise a variety of interfaces, for example, interfaces for data input and output devices (I/O), storage devices, and the like. The interface(s) 308 may facilitate communication through the system 302. The interface(s) 308 may also provide a communication pathway for one or more components of the system 302. Examples of such components include, but are not limited to, processing engine(s) 310 and a database 312.
[0074] The processing engine(s) 310 may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine(s) 310. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine(s) 310 may be processor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing engine(s) 310 may comprise a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine(s) 310. In such examples, the system may comprise the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system 302 and the processing resource. In other examples, the processing engine(s) 310 may be implemented by electronic circuitry.
[0075] In an embodiment, the processor 304 may receive a plurality of inputs and store the information in the database 312 for further processing. In an embodiment, the system 302 and/or the components of the system 302 may be connected to components of the 3D printing assembly 100 of FIG. 1. In an embodiment, the processor 304 may be configured to operate the resin module and enable flow of resin to the nozzle via the conduit 118. Further, in an embodiment, the processor 304 may be configured to utilize a plurality of techniques, the plurality of inputs, and operate the motors (110-A, 110-B) to actuate the cables (104-A, 104-B) and control the nozzle in the flexible arm 102 as the resin is received at the resin dispensing nozzle.
[0076] In an embodiment, the processor 304 may be configured to operate the array of light sources, enable the illumination of the resin, and cause the polymerization reaction, while eclipsing the tip of the nozzle.
[0077] In an embodiment, the processor 304 may be configured to accurately actuate the cables (104-A, 104-B), enable a movement of the flexible arm 102 as the resin undergoes the polymerization, and enable 3D printing on the printing bed 120.
[0078] Although FIG. 3 shows exemplary components of the block diagram 300, in other embodiments, the block diagram 300 of the system 302 may include fewer components, different components, differently arranged components, or additional functional components than depicted in FIG. 3. Additionally, or alternatively, one or more components of the system 302 may perform functions described as being performed by one or more other components of the system 302.
[0079] FIG. 4 illustrates an exemplary flow diagram of a method 400 for implementing the 3D printer with the cable-actuated flexible arm, in accordance with an embodiment of the present disclosure.
[0080] In an embodiment, at step 402, the method 400 may include supplying the resin, by the resin reservoir 112 via the conduit 118 to the nozzle. In an embodiment, the resin may exit the flexible arm 102 through the nozzle configured in the resin module.
[0081] Further, at step 404, the method 400 may include discharging the resin from the nozzle within a view of an array of light sources directed towards a printing bed 120 whose axis may be orthogonal to a plane of motion of the nozzle. Further, the method 400 may include controlling the motors (110-A, 110-B) and the flexible arm 102. The tip of the flexible arm 102 may move at a constant speed and the resin may flow through the nozzle at a constant rate while maintaining a small liquid bridge between the exit orifice of the nozzle and a substrate to ensure that the resin is deposited at a constant rate. In an embodiment, the processor 304 may control the motors (110-A, 110-B) and the flexible arm 102. In an embodiment, the method 400 may include performing a polymerization reaction on the resin, curing and solidifying the resin due to the array of light sources, and enabling 3D printing on the printing bed 120.
[0082] Further, at step 406, the method includes positioning the resin dispensing nozzle to a required position using the flexible arm 102. The resin dispensing nozzle can be positioned in a manner to further enable supply of resin from the resin reservoir 112 for further operations.
[0083] In an embodiment, the process of printing begins with a creation or selection of a 3D digital model using computer-aided design (CAD) software. The 3D digital model can be sliced into thin layers (slices) using slicing mechanism. Each slice can represent a horizontal cross-section of the object.
[0084] In another embodiment, as printing is completed, the printed object can be typically removed from the printing bed 120. The object may then undergo further post-processing steps, such as rinsing in a solvent to remove excess resin and curing under additional UV light to fully harden the material.
[0085] After curing, the printed object may undergo additional finishing processes, such as sanding, polishing, or painting, to achieve the desired surface finish and appearance. The printed object can be inspected for quality and accuracy to ensure it meets the desired specifications. The printed object can further be used in various applications, such as prototyping, product development, medical devices, jewellery making, and more.
[0086] FIG. 5 illustrates exemplary illustrations of printed objects by the apparatus, in accordance with an embodiment of the present disclosure.
[0087] In an embodiment, after some experimental processes, working ranges for a multitude of parameters for the apparatus of the present disclosure are set. The significant ones are the resin flow rate at the exit of the nozzle, the resin viscosity, the layer thickness, the speed of the printhead and the angular velocity of the print bed. The flow rate depends directly on the resin reservoir 112 pressure for given dimensions of the resin conduits and the resin dispensing nozzle.
[0088] The apparatus is tested by printing thin-walled parts, which includes (i) cylinders with circular cross-sections, (ii) prismatic parts with square cross sections, (iii) prismatic parts with hexagonal cross sections, (iv) right- circular cones, and (v) hemispherical domes as disclosed in FIG. 5. The shapes test the accuracy of the apparatus, including positioning of the print head and the print bed 120 motion. In the experimental setups, a flow rate of 0.185 ml/min, using a high viscosity resin (Clear V4 Formlabs with 20% silica by weight), a layer thickness of 0.7 mm, print head speed of 4.5 mm/s and a print bed rotation of 3 rpm was carried out. The surface roughness is measured using a surface roughness tester having a diamond tip radius of 5 µm.
[0089] Printing results with resins having low viscosity and high viscosities is disclosed. The printing result of resin with low viscosity is Clear v4 having a dynamic viscosity of µ = 875 mPa s and the resin with high viscosity has added silica, resulting in a viscosity of µ = 495 Pa s. The viscosities reported correspond to rheometer measurements at low shear rates (approximately 0.1/s). As a result, the printed material with low viscosity resin did not show any damage during or after printing. With high viscosity resin, materials with a solid shape including circular tubes, square tubes, and hexagonal tubes were printed. The circular tube had a height of 80mm and 30 mm radius, the square tube had a height of 80mm height and a 20mm radius, and the hexagonal tube had a height of 80mm height and 15mm radius. The printed material holds shape and has no voids or damage while printing and can be used for a variety of applications explained further.
EXAMPLES
[0090] The 3D printer of the present disclosure can be widely used for rapid prototyping and iterative design processes in various industries, including automotive, aerospace, and consumer electronics. For example, companies can use 3D printing to create prototypes of new vehicle parts and aircraft components before mass production.
[0091] The 3D printer of the present disclosure can also enable production of custom-fit medical devices tailored to individual patients, such as prosthetics, orthotics, and dental implants. For example, many medical facilities can utilize 3D printing to create personalized prosthetic limb covers that reflect the individual style and preferences of each user.
[0092] In another example, in the architecture field, 3D printing can enable the fabrication of architectural models, scale prototypes, and even full-scale structures using various materials. For example, the apparatus in the present disclosure can also be turned into a mobile 3D printer capable of constructing entire houses on-site, reducing construction time and costs.
[0093] In the jewellery and fashion department, 3D printing can allow for creation of intricate and customizable jewellery designs, as well as avant-garde fashion pieces. For example, the 3D printer can produce unique jewellery collections inspired by natural forms and computational design algorithms.
[0094] A person of ordinary skill in the art will readily ascertain that the illustrated steps are set out to explain the exemplary embodiments shown, and it should be anticipated that ongoing technological development will change the manner in which particular functions are performed. The examples are presented herein for purposes of illustration, and not limitation. Further, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed. Alternatives (including equivalents, extensions, variations, deviations, etc., of those described herein) will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein. Such alternatives fall within the scope and spirit of the disclosed embodiments.
[0095] What has been described and illustrated herein are examples of the present disclosure. The terms, descriptions, and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated.

ADVANTAGES OF THE INVENTION
[0096] The present disclosure provides an apparatus for a three-dimensional (3D) printer apparatus that replaces bulky positioning systems in existing 3D printer designs with a cable-actuated flexible arm.
[0097] The present disclosure provides the 3D printer apparatus with the cable-actuated flexible arm controlled accurately over a workspace whose extent can be customized using a cable-actuated flexible arm of varying lengths.
[0098] The present disclosure provides an economical, jointless, and frictionless positioning system for a material dispensing nozzle that avoids the need for expensive and sensitive arrangements compared to existing 3D printer designs.
[0099] The present disclosure provides an apparatus with a cable-actuated flexible arm in which the actuation motors are stationary and located remotely from the material dispensing and curing system.
[00100] The present disclosure provides the 3D printer apparatus with the cable-actuated flexible arm, a material dispenser, and curing system that works independent of gravity. This feature enables the 3D printer to operate in arbitrary orientations, making it especially useful for space applications.
[00101] The present disclosure provides the 3D printer with the cable-actuated flexible arm that utilizes a curing arrangement that polymerizes the photosensitive resin instantaneously without hindering the flow of resin through the nozzle and without needing apparatus to track the nozzle’s movement.
[00102] The present disclosure provides the 3D printer apparatus with a curing apparatus that enables printing with resins of low and high viscosities.
,CLAIMS:1. An apparatus (100) for Three-Dimensional (3D) printing, the apparatus (100) comprising:
a flexible arm (102) detachably coupled to a print bed (120) at one end and configured with a print head (200), comprising of a resin dispensing nozzle and a curing system, at a distal end, wherein the resin dispensing nozzle is receivably engaged to a material dispenser via a plurality of conduits;
one or more cables (104-A, 104-B) configured to actuate the flexible arm (102) operably coupled to the resin dispensing nozzle and the curing system, wherein the one or more cables are operated with a plurality of motors (110-A, 110-B) configured with the print bed (120), to position and orient the resin dispensing nozzle relative to the print bed (120); and
an array of light sources configured to instantaneously cure a material dispensed on the print bed (120) by the resin dispensing nozzle.
2. The apparatus (100) as claimed in claim 1, wherein the one or more cables (104-A, 104-B) are configured to position the print head to enable dispensing of the material on the print bed (120).
3. The apparatus (100) as claimed in claim 1, wherein the flexible arm (102) is configured to operate in a two-dimensional plane parallel to the print bed (120).
4. The apparatus (100) as claimed in claim 1, wherein the plurality of motors is configured to operate the one or more cables (104-A, 104-B) and load the flexible arm (102) by a tension associated with the one or more cables (104-A, 104-B).
5. The apparatus (100) as claimed in claim 1, wherein the plurality of motors (110-A, 110-B) is operably connected to a processor (304), located within or in the vicinity of the apparatus (100), to determine an actuation required to control a tension and a length associated with the one or more cables (104-A, 104-B).
6. The apparatus (100) as claimed in claim 1, wherein the material is a resin that is dispensed at a constant flow rate from the material dispenser.
7. The apparatus (100) as claimed in claim 1, wherein the array of light sources in the print head (200) is configured to project an annular illumination pattern to cure the dispensed material without inhibiting a flow of material at the one or more nozzles.
8. The apparatus (100) as claimed in claim 1, wherein the print bed (120) supporting the printed layers is oriented for gravity-independent printing.
9. The apparatus (100) as claimed in claim 1, wherein the print bed (120) is rotatable about an axis during printing to minimize resin flow during curing and to maintain layer evenness.
10. A method (400) for Three-Dimensional (3D) printing, the method (400)
comprising:
supplying resin, from a resin reservoir (112), via a conduit (118), to a resin
dispensing nozzle at constant flow rate;
discharging the resin from the resin dispensing nozzle within a view of an
array of light sources directed towards a rotating print bed (120), wherein an axis
of the rotating printing bed (120) is orthogonal to a plane of motion of the resin
dispensing nozzle; and
positioning the resin dispensing nozzle using the cable-actuated flexible
arm (102).