Digital modeling and fabrication

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Digital modeling and fabrication is a design and production process that combines 3D modeling or computing-aided design (CAD) with additive and subtractive manufacturing. Additive manufacturing is also known as 3D printing, while subtractive manufacturing may also be referred to as machining, [1] and many other technologies can be exploited to physically produce the designed objects. [2]

Contents

Modeling

Digitally fabricated objects are created with a variety of CAD software packages, using both 2D vector drawing, and 3D modeling. Types of 3D models include wireframe, solid, surface and mesh. A design has one or more of these model types. [3]

Machines for fabrication

Three machines are popular for fabrication:

1. CNC router

2. Laser cutter

3. 3D Printer

CNC milling machine

CNC stands for "computer numerical control". CNC mills or routers include proprietary software which interprets 2D vector drawings or 3D models and converts this information to a G-code, which represents specific CNC functions in an alphanumeric format, which the CNC mill can interpret. The G-codes drive a machine tool, a powered mechanical device typically used to fabricate components. [4] CNC machines are classified according to the number of axes that they possess, with 3, 4 and 5 axis machines all being common, and industrial robots being described with having as many as 9 axes. CNC machines are specifically successful in milling materials such as plywood, plastics, foam board, and metal at a fast speed. CNC machine beds are typically large enough to allow 4' × 8' (123 cm x 246 cm) sheets of material, including foam several inches thick, to be cut.

Laser cutter

The laser cutter is a machine that uses a laser to cut materials such as chip board, matte board, felt, wood, and acrylic up to 3/8 inch (1 cm) thickness. The laser cutter is often bundled with a driver software which interprets vector drawings produced by any number of CAD software platforms. [5]

The laser cutter is able to modulate the speed of the laser head, as well as the intensity and resolution of the laser beam, and as such is able in both to cut and to score material, as well as approximate raster graphics. [6]

Objects cut out of materials can be used in the fabrication of physical models, which will only require the assembly of the flat parts.

3D printers

3D printers use a variety of methods and technology to assemble physical versions of digital objects. Typically desktop 3D printers can make small plastic 3D objects. They use a roll of thin plastic filament, melting the plastic and then depositing it precisely to cool and harden. They normally build 3D objects from bottom to top in a series of many very thin plastic horizontal layers. This process often happens over the course of several hours.

Fused deposition modeling

Fused deposition modeling, also known as fused filament fabrication, uses a 3-axis robotic system that extrudes material, typically a thermoplastic, one thin layer at a time and progressively builds up a shape. Examples of machines that use this method are the Dimension 768 and the Ultimaker.

Stereolithography

Stereolithography uses a high intensity light projector, usually using DLP technology, with a photosensitive polymer resin. It will project the profile of an object to build a single layer, curing the resin into a solid shape. Then the printer will move the object out of the way by a small amount and project the profile of the next layer. Examples of devices that use this method are the Form-One printer and Os-RC Illios.

Selective laser sintering

Selective laser sintering uses a laser to trace out the shape of an object in a bed of finely powdered material that can be fused together by the application of heat from the laser. After one layer has been traced by a laser, the bed and partially finished part is moved out of the way, a thin layer of the powdered material is spread, and the process is repeated. Typical materials used are alumide, steel, glass, thermoplastics (especially nylon), and certain ceramics. Example devices include the Formiga P 110 and the Eos EosINT P730.

Powder printer

Powder printers work in a similar manner to SLS machines, and typically use powders that can be cured, hardened, or otherwise made solid by the application of a liquid binder that is delivered via an inkjet printhead. Common materials are plaster of paris, clay, powdered sugar, wood-filler bonding putty, and flour, which are typically cured with water, alcohol, vinegar, or some combination thereof. The major advantage of powder and SLS machines is their ability to continuously support all parts of their objects throughout the printing process with unprinted powder. This permits the production of geometries not easily otherwise created. However, these printers are often more complex and expensive. Examples of printers using this method are the ZCorp Zprint 400 and 450.

See also

Related Research Articles

<span class="mw-page-title-main">Numerical control</span> Computer control of machine tools

In machining, numerical control, also called computer numerical control (CNC), is the automated control of tools by means of a computer. It is used to operate tools such as drills, lathes, mills, grinders, routers and 3D printers. CNC transforms a piece of material into a specified shape by following coded programmed instructions and without a manual operator directly controlling the machining operation.

<span class="mw-page-title-main">Selective laser sintering</span> 3D printing technique

Selective laser sintering (SLS) is an additive manufacturing (AM) technique that uses a laser as the power and heat source to sinter powdered material, aiming the laser automatically at points in space defined by a 3D model, binding the material together to create a solid structure. It is similar to selective laser melting; the two are instantiations of the same concept but differ in technical details. SLS is a relatively new technology that so far has mainly been used for rapid prototyping and for low-volume production of component parts. Production roles are expanding as the commercialization of AM technology improves.

<span class="mw-page-title-main">Stereolithography</span> 3D printing technique

Stereolithography is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photochemical processes by which light causes chemical monomers and oligomers to cross-link together to form polymers. Those polymers then make up the body of a three-dimensional solid. Research in the area had been conducted during the 1970s, but the term was coined by Chuck Hull in 1984 when he applied for a patent on the process, which was granted in 1986. Stereolithography can be used to create prototypes for products in development, medical models, and computer hardware, as well as in many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.

<span class="mw-page-title-main">Fab lab</span> Small-scale workshop for digital fabrication

A fab lab is a small-scale workshop offering (personal) digital fabrication.

<span class="mw-page-title-main">3D printing</span> Additive process used to make a three-dimensional object

3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer control, with the material being added together, typically layer by layer.

<span class="mw-page-title-main">RepRap</span> Self-replicating 3D printer initiative

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S. Scott Crump is the inventor of fused deposition modeling (FDM) and co-founder of Stratasys, Ltd. Crump invented and patented FDM technology in 1989 with his wife and Stratasys co-founder Lisa Crump. He is currently the chairman of the board of directors of Stratasys, which produces additive manufacturing machines for direct digital manufacturing ; these machines are popularly called “3D printers.” He took the manufacturing company public in 1994 (Nasdaq:SSYS). He also runs Fortus, RedEye on Demand, and Dimension Printing – business units of Stratasys.

<span class="mw-page-title-main">CAD/CAM dentistry</span> Computer-aided design and manufacturing of dental prostheses

CAD/CAM dentistry is a field of dentistry and prosthodontics using CAD/CAM to improve the design and creation of dental restorations, especially dental prostheses, including crowns, crown lays, veneers, inlays and onlays, fixed dental prostheses (bridges), dental implant supported restorations, dentures, and orthodontic appliances. CAD/CAM technology allows the delivery of a well-fitting, aesthetic, and a durable prostheses for the patient. CAD/CAM complements earlier technologies used for these purposes by any combination of increasing the speed of design and creation; increasing the convenience or simplicity of the design, creation, and insertion processes; and making possible restorations and appliances that otherwise would have been infeasible. Other goals include reducing unit cost and making affordable restorations and appliances that otherwise would have been prohibitively expensive. However, to date, chairside CAD/CAM often involves extra time on the part of the dentist, and the fee is often at least two times higher than for conventional restorative treatments using lab services.

Electron-beam additive manufacturing, or electron-beam melting (EBM) is a type of additive manufacturing, or 3D printing, for metal parts. The raw material is placed under a vacuum and fused together from heating by an electron beam. This technique is distinct from selective laser sintering as the raw material fuses have completely melted. Selective Electron Beam Melting (SEBM) emerged as a powder bed-based additive manufacturing (AM) technology and was brought to market in 1997 by Arcam AB Corporation headquartered in Sweden.

<span class="mw-page-title-main">Rapid prototyping</span> Group of techniques to quickly construct physical objects

Rapid prototyping is a group of techniques used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design (CAD) data. Construction of the part or assembly is usually done using 3D printing or "additive layer manufacturing" technology.

Custom-fit means personalized with regard to shape and size. A customized product would imply the modification of some of its characteristics according to the customers requirements such as with a custom car. However, when fit is added to the term, customization could give the idea of both the geometric characteristics of the body and the individual customer requirements, e.g., the steering wheel of the Formula 1 driver Fernando Alonso.

<span class="mw-page-title-main">Selective laser melting</span> 3D printing technique

Selective laser melting (SLM) is one of many proprietary names for a metal additive manufacturing (AM) technology that uses a bed of powder with a source of heat to create metal parts. Also known as direct metal laser sintering (DMLS), the ASTM standard term is powder bed fusion (PBF). PBF is a rapid prototyping, 3D printing, or additive manufacturing technique designed to use a high power-density laser to melt and fuse metallic powders together.

<span class="mw-page-title-main">Powder bed and inkjet head 3D printing</span> 3D printing technique

Binder jet 3D printing, known variously as "Powder bed and inkjet" and "drop-on-powder" printing, is a rapid prototyping and additive manufacturing technology for making objects described by digital data such as a CAD file. Binder jetting is one of the seven categories of additive manufacturing processes according to ASTM and ISO.

Laser Rapid Manufacturing (LRM) is one of the advanced additive manufacturing processes that is capable of fabricating engineering components directly from a solid model.

<span class="mw-page-title-main">Fused filament fabrication</span> 3D printing process

Fused filament fabrication (FFF), also known as fused deposition modeling, or filament freeform fabrication, is a 3D printing process that uses a continuous filament of a thermoplastic material. Filament is fed from a large spool through a moving, heated printer extruder head, and is deposited on the growing work. The print head is moved under computer control to define the printed shape. Usually the head moves in two dimensions to deposit one horizontal plane, or layer, at a time; the work or the print head is then moved vertically by a small amount to begin a new layer. The speed of the extruder head may also be controlled to stop and start deposition and form an interrupted plane without stringing or dribbling between sections. "Fused filament fabrication" was coined by the members of the RepRap project to give an acronym (FFF) that would be legally unconstrained in its use.

Digital manufacturing is an integrated approach to manufacturing that is centered around a computer system. The transition to digital manufacturing has become more popular with the rise in the quantity and quality of computer systems in manufacturing plants. As more automated tools have become used in manufacturing plants it has become necessary to model, simulate, and analyze all of the machines, tooling, and input materials in order to optimize the manufacturing process. Overall, digital manufacturing can be seen sharing the same goals as computer-integrated manufacturing (CIM), flexible manufacturing, lean manufacturing, and design for manufacturability (DFM). The main difference is that digital manufacturing was evolved for use in the computerized world.

<span class="mw-page-title-main">3D printing processes</span> List of 3D printing processes

A variety of processes, equipment, and materials are used in the production of a three-dimensional object via additive manufacturing. 3D printing is also known as additive manufacturing, because the numerous available 3D printing process tend to be additive in nature, with a few key differences in the technologies and the materials used in this process.

Multi-material 3D printing is the additive manufacturing procedure of using multiple materials at the same time to fabricate an object. Similar to single material additive manufacturing it can be realised through methods such as FFF, SLA and Inkjet 3D printing. By expanding the design space to different materials, it establishes the possibilities of creating 3D printed objects of different color or with different material properties like elasticity or solubility. The first multi-material 3D printer Fab@Home became publicly available in 2006. The concept was quickly adopted by the industry followed by many consumer ready multi-material 3D printers.

References

  1. ↑ "What is digital modeling and fabrication? - Definition from WhatIs.com". SearchManufacturingERP. Archived from the original on 2017-07-04. Retrieved 2016-02-17.
  2. ↑ Bickel, B.; Cignoni, P.; Malomo, L.; Pietroni, N. (2018). "State of the Art on Stylized Fabrication" (PDF). Computer Graphics Forum. 37 (6): 325–342. doi:10.1111/cgf.13327. hdl: 10453/129681 . S2CID   51870522.
  3. ↑ "About Modeling 3D Objects | AutoCAD | Autodesk Knowledge Network". knowledge.autodesk.com. Retrieved 2016-02-17.
  4. ↑ Lynch, Mike (19 October 2011). "Five CNC Myths and Misconceptions | Modern Machine Shop". www.mmsonline.com. Retrieved 2016-02-17.
  5. ↑ "Smart Desktop Laser Cutter and Engraver | xTool Laser". www.xtool.com. Retrieved 2023-11-30.
  6. ↑ Industries, Precision Metal. "Automated Laser Cutting | Precision Metal Industries". www.pmiquality.com. Retrieved 2016-02-17.
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