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ABSTRACT
Fabbers are machines that are capable of fabricating useful items on demand from computer-generated design specifications. It is meant to be used in our homes as free form fabricating machines.
Even though such machines have to overcome several obstacles scientists in Cornell computational Synthesis Laboratory have taken the first steps toward the creation of a fabricating system that can produce small, simple robots incorporating a battery, actuators, and sensors. They have succeeded in creating a small fabber that makes a coin-shaped battery and an actuator suitable for the envisioned robot. Compact and yet capable fabbers point the way toward a future where the term "online shopping" takes on a whole new meaning. Imagine purchasing a piece of software that encodes detailed specifications of something and then seeing that object emerge from a box on your desk not bigger than a microwave oven. Like your desktop printer today, this desktop fabber would use some sort of cartridges. And just as desktop-printer cartridges contain the inks that can produce a limitless variety of images, the fabber cartridges would contain the necessary raw materials to create a profusion of desired items. Not every consumer product is suitable for fabbing, of course, but anything whose materials cost is low compared with its intellectual investment is a contender. A few examples are electric toothbrushes, cell phones, eyewear, toys, costume jewelry, and other decorative items .Although many technical hurdles must be cleared before home fabbing can become a reality, and itâ„¢s already possible to see its huge implications for engineers, designers, and distributors. Manufacturing, at least for things that could be fabbed, would be divorced from rigid corporate control, spawning new classes of independent designers. Much of the stock and delivery costs associated with conventional manufacturing would be eliminated. And with appropriate software, a product could be customized, enabling a system of bespoke production almost inconceivable today.
The focus of this paper is on the architecture of a 100% automatic, self-contained and versatile fabrication process, capable of autonomously producing an entire working machine with no human intervention

INTRODUCTION
In the future, a new kind of Internet appliance will allow people to download the digital description of a product and have that product made immediately and automatically. This appliance is called a digital fabricator, or fabber. Fabbers use 21st-century technology to translate digital product data into physical goods. The data can be transmitted over the Internet and the product fabbed at any local node. Fabbers are the page link between old-fashioned, industrial-era manufacturing and the coming magic of nanotechnology
Digital fabbers transact the magic of producing physical products from digital information A fabricator (or fabber) is an ultra-modern machine that makes things automatically. Fabricators use raw materials and computer data to generate three-dimensional, solid objects you can hold in your hands, submit to testing, or assemble into working mechanisms. They could make a huge variety of reasonably complicated objects, and yet was attainable by ordinary people, would transform human society to a degree that few creations ever have. Fabbers have been derived from machines that were once used exclusively by manufacturers to prototype new designs. With such machines, people can, in effect, download such complex objects as bicycles, chemical sensors, radios-and eventually robots, and may be even prosthetic limbs-much as they now download music and video files.
From a CT scan of a patient's fractured skull, surgeons recently printed out a 3-D model they could use to plan their operation. At the moment, the objects can be made only of plastic, but various schemes for fabbing things out of metal are under development. Manufacturers around the world for low-volume production, prototyping, and mold mastering are using them. Scientists and surgeons for solid imaging, and by a few modern artists for innovative computerized sculpture also use them. Manufacturers report enormous productivity gains from using fabricators. As the quality and speed of fabricator output steadily improves, we are gradually moving toward a time when these machines will be able to participate in the construction of large structures and make parts to be incorporated into working machinery.
This paper investigates several of the issues important to evaluating the opportunity to reduce transportation costs by using fabricators for on-site generation of machine parts and construction components.
CONCEPT OF FABBER
Technologies currently under development and in limited commercial use today present the future possibility of distributing physical products on the Internet by downloading and manufacturing directly in customersâ„¢ homes and offices or in local facilities .
Digital manufacturing is performed by a family of modern technologies that capture, transmit, and manifest 3-D digital descriptions of physical products. The central technology is the digital fabricator or fabber, also called a 3-D printer because it does 3-D digital output in solid material. Invented for use by engineers in rapid prototyping of all manner of products, from automobiles to zippers, fabbers are now also used by physicians and scientists, Hollywood prop makers, digital sculptors etc.
People one day will be able to go online and order whatever they want and have it .We intend to show you not only that it is possible, but that itâ„¢s on its way, through a new family of technologies called digital fabbers. And weâ„¢re going to talk about how fabbers hook into the P2P Internet to create a whole new opportunity for sharing of digital data
Fabbers work by these basic processes


- Subtractive. Starting with a solid block, material is removed a piece at a time to form the desired shape. Carving is the primary example of subtractive fabrication.
- Additive. Material is built up from smaller units into the intended shape. Masonry, the construction of walls and buildings from blocks of stone, is an additive process.
- Formative. Without either adding or removing anything, forces are applied to various points of a pliable material to give it a specific shape without adding or removing material. A potter shaping clay by pushing on it with her fingers is using formative fabrication.
All manufacturing fabrication is done by one or a combination of these three basic techniques, whether we are talking about ancient, manual work or modern, automated processes.
The first techniques for automating fabrication of physical shapes were analog processes that copied the shape of one object to form another. The primary example of analog fabrication is molding, in which a fluid or pliable material is poured or pushed into a cavity where it solidifies, taking the shape of the cavity. If a mold can be reused many times, it allows many copies of a product to be manufactured easily by creating the shape only once in the form of the original mold. In some cases a mold can be used only once, but the mold is made out of a material that is much easier to work with than the material used to make the final product in the mold.
Analog fabrication allows the same categorization into three basic fabrication techniques. Molding is a formative analog process because it works by applying forces to the sides of a material without adding or removing material. There are also subtractive analog techniques that work like a pantograph, following the shape of an existing object to determine the pattern carved into a solid block of supplied material.
Building on the history of manual and analog fabrication, digital fabrication works by first encoding the shape of the desired product in a numerical form, and then using this code to control the operation of sophisticated, automated equipment to give shape to the raw material. As with analog fabrication, digital fabrication can be subtractive, additive, or formative .Even before the appearance of computers, techniques were discovered for digitizing the shape of helicopter rotors and using the resulting numeric code to control the machining of those shapes. This earliest form of digital fabrication was called NC (numerically controlled) machining. With the advent of computers, NC was followed by CNC (computer-numerically controlled) machining, in which the numerical code was stored and could be manipulated in a computer.
The difference is that they automate those processes, taking their instructions from a digital file that describes the desired shape and structure. Fabbers combine digital data with physical material to make products. Fabbers today are limited to making simple products in simple materials, but in the not-too-distant future, fabbers will be able to make almost any product you can imagine (and may be some we canâ„¢t imagine)
In this presentation, we will be speaking about an important aspect of our technology, how it ties into the Internet. Digital fabbers create a whole new paradigm for manufacturing, which is an iteration cycle that starts with a digital representation for a product. The data can come from a designer using CAD or from scanning an existing product. The data is transformed into physical material by a fabber. Fabbers can be connected to data anywhere in the world by the Internet Fabbers today are used primarily for rapid prototyping, making models of new product designs for manufacturing engineers and manufacturing designers. They are also used by medical doctors for surgical planning models or custom-fitting prostheses, as well as by architects. We are starting to see companies tie the magical capabilities of fabbers to the Internet. ToyBuilders.com uses fabbers to make toys from customersâ„¢ own designs.
Control research: Incorporating intelligence in machines
Control is the essence of automated fabrication. It links the mind of the user with the physical processes that create the desired object. The two most important elements of control are the representation of the desired geometry in computer code and then translation of this code into instructions to guide the fabrication process. (See Figure) .The geometry may arise from a human design, from scanning the shape of an existing object, or from another mathematical source. In the course of fabrication, a good system will monitor its ongoing results and feed them back to the control computer. After the object is made, the user may evaluate the results and decide whether to make certain changes to the design or to the process parameters.

The key elements, shown here with underlined labels, are the representation of abstract geometry in computer code and the creation of machine instructions to direct the fabrication process.
One very interesting challenge in the arena of control research involves the coordination of multiple process sites. The ability to process material in several places at once offers opportunities for dramatic improvements in speed and efficiency. At the interface between the user and the fabricator, we can expect to see dramatic improvements in 3-D CAD systems. Computer screens, keyboards, and mouses will give way to 3-D displays with interactive fingertip point indication and voice instruction. All of these technologies are currently under development. Developments in virtual reality technology are making important contributions here. Another element, automatic mechanical property prediction, will allow the user to read the strength of a material in a design in the same way as drawing programs today indicate color on a monochrome screen with various patterns of shading and hatching.
For the more serious fabricator user, there will be matter programming languages. To understand this concept, notice that a fabricator is a machine that does with matter what a computer does with information: it takes it in in one form, performs some operations on it, and sends it back out in a different form. A matter language is a system of coded communication that gives a person intimate control over those operations without the person needing to know the details of how the operations are performed. This provides the same advantages that a computer programmer gets from using C or Pascal to achieve efficient, robust processing without needing to be concerned about computer registers and accumulators. Instead of drawing an object graphically in CAD, the matter programmer writes the object in process code.
Work underway today in laboratories around the world is making great strides in understanding and improving the processes, materials, and control strategies at work in automated fabricators. While the improvements seen in commercial systems in just the last few years are certainly dramatic, these developments have only begun to explore the potential for generating 3-dimensional, solid objects under computer control
As the quality and speed of fabricator output steadily improves, we are gradually moving toward a time when these machines will be able to participate in the construction of large structures and make parts to be incorporated into working machinery.

HISTORY OF FABBER
Home fabbing has a precursor in the array of rapid-prototyping systems now used routinely in various industries. These include systems for electronic and others for mechanical prototype.

MECHANICAL
The mechanical ones are called Solid-Freeform Fabricators and can make objects of any shape. During the past 30 years solid-freeform prototyping has matured into a multibillion-dollar industry.
ELECTRONICS
The electronics-oriented systems fall under the category of Direct-Write electronics.
Rapid-prototyping systems, both electrical and mechanical, work by incrementally and selectively depositing material from a source onto a substrate. The machines read data describing slices of a computer model and, using one of several methods, lay down successive thin layers of liquid or powdered polymers, ceramics, or metals.
SOLID-FREEFORM SYSTEMS
The solid-freeform systems are commonplace tools for industrial designers. They are used mostly by automakers to create prototypes of car parts, from engine block to side-view mirrors; by appliance manufacturers to model products such as air conditioners and microwave ovens; and by consumer electronics companies to model Bluetooth headsets, cell phones, and other products. The industrial rapid-prototyping systems use inks, pastes, and suspensions that are combinations of filaments, powders, flakes, precursors, cross-linkers, binders, solvents, dispersants, and surfactants, whose properties-including viscosity, density melting point, and surface tension are tailored to particular applications.
Currently, rapid prototypes can fashion plastics, ceramics, and certain metals into almost any kind of mechanical structure, including sliding and rotary kinematic joints, springs, gears, ratchets, nuts, and bolts, with quality good enough for functional testing. Many solid prototypes incorporate a tough, rigid plastic, called Acrylonitrile-Butadiene-Styrene (ABS).Electronics maker Logitech Inc., in Fremont, California, used a freeform machine from Stratsys Inc., In Eden Prairie, Minn., to make an ABS prototype of its Bluetooth headset and then attached weights to the boom microphone to test the design for strength. Another Stratasys customer, Diebold Inc., in North Canton, Ohio, builds automated teller machine prototypes made of ABS or polycarbonate and tests their endurance in rain, sleet, snow, and extreme temperatures. Grotell Design Inc., in New York City, makes prototypes of all its watch components, from bracelets to bezels, using thermoplastics, natural and synthetic waxes, and even fatty esters in desktop solid-freeform fabricators made by Solidscape Inc., in Merrimack, N.H.
DIRECT-WRITE METHODS
For electrical engineers, direct-write methods for creating electronic prototypes have progressed from their origins as simple plotters for electronic circuits to an emerging family of commercial machines. The new machines, which can deposit a variety of materials over different surfaces according to software design .are mostly for printed-circuit board models. With inkjet ,plasma ,thermal spray ,pen, and laser-based methods ,they lay down lines ranging in width from nanometers to centimeters .The prototypes are made from metals ,ceramics, ferrites ,semiconductors, and polymers ,as well as various composite materials such a polymer ceramics for resistors and similar components. The techniques work at low temperatures and can write lines at speeds approaching one meter per second.
Todayâ„¢s most advanced direct-write techniques work not only on flat boards but also on nonplanar substrates, and even textiles to make flexible and compact circuits that confirm to the tight space requirements of certain consumer products. Because direct write lends itself not only to prototyping but also to small-scale production of specialty parts ands devices, the U.S.Defense Advanced Research Projects Agency has poured millions of dollars into the technologiesâ„¢ development. DARPA is funding a project by Potomac Photonics Inc., in Lanham, Md., to develop and commercialize laser-based direct-write tools that can deposit metal, dielectric, and ferrite materials onto a variety of substrates by melting a stream of powdered materials such as titanium. It will make custom circuit boards, complete with conductive traces, resistors, capacitors, and inductors. Another DARPA-funded company, MesoScribe Technologies Inc., in Stony Brook, N.Y., has developed a thermal-spray technique that accelerates particles to directly write a thermocouple on a curved, ceramic-coated gas turbine blade to monitor the heat of fuel combustion.
When to use a fabber
There are four criteria that determine whether a project is appropriate for a fabber:
Low volume
Shape data is available in computerized form
The desired shape is complex
The ability to make changes is useful
In this list, the first two are mandatory: a fabber is not appropriate for direct high-volume production (although it can be used to make a copy tool, which can then be used to make large quantities of a product or part), and it cannot be used without computerized shape data. The third and fourth criteria are optional but determine the importance of using a fabber: The more complex a shape is, and the more likely one is to benefit from the ability to iterate the design, the more advantage is likely to be obtained from using a fabber.
STEPS INVOLVED IN FABBING
1. Choose a fabber:-Visit the catalogue page to pick out the fabber that you would like, and to find information about building your own fabber. You will need to purchase the parts for the fabber, and also some simple tools to build the machine with. We hope that in the near future maybe someone will also be willing to build and sell assembled machines
2. Install the software: - Download and install the software binaries. Check that it talks to the printer and you are able to manually jog the carriage. Later, you can download the source code, see how it works and improve it.
3. Get some building materials: - Visit the materials page to select some materials. Start with a simple material like play dough or 1-part silicone. Later you can move on to more sophisticated materials, cocktails, and multi-material assemblies.
4. Download an object to print: - Visit the Models page and download geometry to print. Start with something simple like a cube or a dome. Later you can explore more complex structures.
5. Print the object:- Load the syringe with material, and print the object using the software

PROCESSES
There are three basic categories of additive fabrication technologies: aimed deposition, selective sintering, and selective curing. These are briefly described in the following subsections
1. SELECTIVE CURING

In selective curing, a liquid resin is caused to cure (harden) in specific locations to grow the desired object. The Earth-based version of this, using organic photopolymers, is not practical for space applications because of the absence of organic base materials. However, the abundance of silicon on the Moon may offer the basis of a whole new industry in silicon-based polymers. Todayâ„¢s silicones are polymers with an alternating silicon-oxygen backbone. They can be made into photopolymers, but currently this is done by hanging organic functional groups on the inorganic backbone. It is possible that we will see fully inorganic photopolymers in the future, or polymer resins that are subject to another form of selective curing, such as thermal or voltaic. If such materials do become available, it will be interesting to consider their use in fabricators on the Moon or other silicon-rich environments.
2. SELECTIVE SINTERING
In selective sintering, a powder is caused to melt in specific locations, and the melted powder then fuses into a contiguous solid, which builds up the shape of the desired object. Although most fully developed for use with thermoplastics, there has been successful study of its application to metal and ceramic powders. There are three approaches to achieving sintering of a metallic or ceramic feedstock:
- Using a very high-energy beam to achieve sufficient heating to directly melt a standard, high-melting-point metal or ceramic.
- Using a beam of moderate energy with a low-melting-point alloy or a mixture that includes a low-melting-point component.
- Using a metal or ceramic powder either with a polymer coating or with a polymer component mixed into the powder. The selective sintering process then actually operates on the polymer coating or component in order to form a green body which is later subjected to bulk heating to burn out the polymer and cause direct fusing of the metal.
On Earth, the energy beam is generally supplied by a laser, although electron beams have also been proposed. In space, an excellent source of thermal energy is likely to be concentrated sunlight.
Selective sintering is a promising technique for near-term testing of space applications. This is because some success has been demonstrated in applications to metals already, and because raw metal and ceramic powders are available on the moon. Any of the three approaches listed above may be used. For polymer-coated powders, the polymer would need to be supplied from Earth, but the mass of polymer consumed would be small compared to the mass of metal fabricated, so the goal of reduced transportation costs would be accomplished.
3. AIMED DEPOSITION
In aimed deposition, a stream of material is aimed at specific locations on the growing object to build it up. The material may be deposited in the form of droplets or in a continuous bead. A number of projects have studied application of this technique to metals. It may be suitable for use in space, using feed stocks melted in a solar-heated crucible. This is a promising technique, which could emerge as the method of choice for fabricating in metals. However, the application of the technology to metals is quite immature. Many issues need to be resolved in earthbound development before it is practical to test this technique for space applications.

The Offset Fabbing process in action.
An individual pattern is formed of a thin film resting on a supporting carrier. This pattern is then brought into contact with the growing body of the object being made and bonded in precise position. Finally, the carrier is removed to make way for attachment of the ongoing succession of patterns.
TOOLS OF DIGITAL MANUFACTURING
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While fabbers play the central role, the full story of digital manufacturing is actually the interplay of four technologies.
3-D CAD (computer aided design) is the basic tool for creating and changing the design of a product. CAD programs today are quite technical tools, but at their most fundamental level they are just fancy 3-D drawing programs, the 3-D analog of programs like Corel Draw and PhotoShop. CAD has been getting much easier to use and much less expensive in recent years and this trend will continue. Also, new user interface tools, like the 3-D mouse, 3-D displays, and voice input will make these programs still easier. At the same time, those common drawing programs (Corel, PhotoShop, etc.) will add 3-D features and capabilities until CAD will cease to exist as a separate category and will merge with the category of 3-D graphical drawing programs.
3-D scanners are like the 3-D version of inexpensive scanners that people use to put photographs into their computers. But instead of just reading the 2-D contours of a picture or document, 3-D scanners digitize the whole 3-D shape of a solid object. Moreover, while some scanners are limited to reading the exterior shape, there are others that use X-rays or other techniques to scan inside and out, reading internal structure as well.
Fabbers. As discussed above, a fabber (digital fabricator) is a factory in a box that makes things automatically from digital data. It takes a design created in 3-D CAD or captured by a 3-D scanner and turns it into physical material. Like a scanner, a fabber is a computer peripheral. Itâ„¢s like a computer printer, but instead of printing an image on a flat sheet of paper, a fabber makes a real, 3-D product.
The Internet ties together CAD computers, scanners, and fabbers around the world to form a globe-spanning mesh of communication that can transform a design in Philadelphia into a product in Paris, or take a statue in Bangladesh and produce a replica in Buenos Aires.
FABBERS AND THE INTERNET

In the future, a new kind of Internet appliance will allow people to download the digital description of a product and have that product made immediately and automatically. This appliance is called a digital fabricator, or fabber. Fabbers use 21st-century technology to translate digital product data into physical goods. The data can be transmitted over the Internet and the product fabbed at any local node. Fabbers are the page link between old-fashioned, industrial-era manufacturing and the coming magic of nanotechnology.
Digital fabbers transact the magic of producing physical products from digital information. A fabber is a three-dimensional printer. It renders 3-D digital data in solid material. On the Internet, with broadband access, a fabber is an appliance for recreating artifacts and delivering products directly into the userâ„¢s office or home. Fabbers transform the Internet from a network of information into a network for physical delivery of real products.
Todayâ„¢s fabbers are not yet up to fabbing just any product a customer may desire. Todayâ„¢s fabbers work in simple plastics or low-strength metals and are limited in their building precision. Tomorrowâ„¢s fabbers will make fully functional products with moving parts and integrated micro circuitry.
While fabbing of consumer products in peopleâ„¢s homes is off in the future, todayâ„¢s limited fabbers have become important in high-value, time-critical, business applications
As valuable as they are, todayâ„¢s fabbers are big, expensive machines costing between $45,000 and $800,000. They typically use toxic chemicals or powders as feed materials. They are like the old mainframe computers of the 1960s that needed a temperature-controlled environment and specially trained operators.
Despite their high cost and complexity, todayâ„¢s fabbers have been widely accepted among the leading manufacturing companies of the world as an indispensable tool for new product development. Many companies that own fabbers today have experienced a return on their initial investment in less than one year.
But the market for fabbers today is severely limited by three factors: speed, cost, and convenience. Todayâ„¢s fabbers are too slow, too expensive, and too cumbersome to make their way out of the industrial laboratories where they are now used.
The opportunity exists to create a whole new market for digital fabber that grows the industry from its currently limited base to a much larger audience. This will be similar to the transition of computers from mainframes to PCs, with the faster speed, lower cost, and easier-to-use products penetrating into vast new markets.
Coming Capabilities
A whole set of new opportunities arises when we fab products additively. In subtractive and formative fabrication we carve or mold an existing material supplied in bulk form. But in additive fabrication we are literally creating new material as we build up the product. There are several levels of new capabilities that arise in this way.
Internal structure. At the simplest level, additive fabbing allows our processing to determine not only the external shape of the product, but the internal structure as well. Instead of specifying that we want a 3-centimeter-diameter sphere, for example, we can describe whether the sphere should be solid or hollow or be constructed of concentric rings of various materials. Perhaps we would like the interior to be a scaffolding-like web of struts or foam of octahedral cavities. These kinds of details used to require a complex series of individual manufacturing steps if they were possible at all. Additive fabbing presents the possibility of producing such structures automatically with only the requirement of a valid digital description and a supply of the appropriate raw materials.
Mechanisms and circuitry. If we can form internal structure, then that structure can include void regions that provide clearance for individual parts to slide over each other. This capability was first demonstrated with the gear tree fabbed on the Cubital Solider in the early 1990s. The gear tree is a structure of twelve interlocking gears, all fabbed simultaneously in place on their axles that rotate in unison when any one of them is turned. In the future we can expect to see advanced fabbers making complex machines, such as clothes washers, computer disk drives, automobiles, and space vehicles. In addition to moving parts, products like these require integrated electronic microcircuitry, which will also be enabled as additive fabbing is advanced to working at finer and finer scales.
Novel materials. What is a material? There are only 92 naturally occurring species of atoms in the world, plus about a dozen more man-made varieties. Different kinds of materials arise from combining these different atoms, first at the level of molecules, and then combining those molecules in a limitless variety of organizational schemes. New materials, such as plastics, intermetalics, and composites, were among the miracles of the 20th century. But these materials were always made in bulk form. Additive fabbing gives us the opportunity to tailor material properties to individual geometrical locales of a product, to fab distinct materials side by side, and to create heretofore unknown materials by combining raw species in new ways. The resulting operational characteristics of 21st-century products are literally unimaginable from where we stand today.
Nanotechnology. The holy grail of digital manufacturing is Eric Drexlerâ„¢s vision of nanotechnology, fabbing all manner of products literally atom-by-atom. No one can predict exactly when this dream will come true, but it is definitely on the horizon and approaching more and more rapidly with further advances in additive fabbing
Impact
The advent and proliferation of digital manufacturing will have as profound an impact on society and economics as any other technology in history, including the steam engine of the19th century and the automobile, telecommunications, and the computer of the 20th. Here is a brief discussion of some of the primary ways fabbers and digital manufacturing will change the world.
1. Undoing the Industrial Revolution
2. Restructuring Labor and Employment

ADVANTAGES
Some of the advantages of fabricators over other means of generating solid objects are:
Direct generation based on digital data, without the errors arising from a tradesmanâ„¢s interpretation of the designerâ„¢s drawings
Ease of iteration. Part of a design can be changed and the object refabricated without the need to redo the design of the entire object
Accuracy and repeatability of dimensions on the order of 25 to 250 microns (0.001 to 0.01 inch)
For the additive processes, the ability to generate shapes of arbitrary geometric complexity, including composite and nested structures made without assembly and without seams
Fast. Imagine a high-speed label applicator, stamping successive labels out one on top of another. Thatâ„¢s an Offset Fabber. This is the best hope yet for blazing speed in digital fabrication.
Safe and Clean, using ordinary pressure sensitive materials like those found in Scotch Tape. There are no lasers, toxic chemicals, fumes, hot surfaces, or other dangers to worry about.
Dependable, unattended operation, because the simplicity of the process allows it to be fully automated at low cost.
Full Market Range, from inexpensive office units to huge, industrial fabbers stamping out full-size car-body and boat-hull models.
Broad Material Range. Development has been conducted on feed tapes made from metals, ceramics, and advanced aerospace composites. Ultimately, almost any material can be used, as long as it can be formed into a film and undergo some kind of bonding from layer to layer.
Offset Fabbers could become a mainstream tool for fabricating models, prototypes, and, later, actual products. They are fast, inexpensive, versatile machines that open tremendous new opportunities in manufacturing, education, and medicine. In a world becoming crowded with complicated rapid prototyping technologies


CHALLENGES
Although the researchers have made a great deal of progress during the last five years, many technological challenges stand between the laboratory systems of today and the universal fabber of tomorrow. For example,
1. Rapid prototyping is actually a misnomer: with very low typical printing rates at cubic inch per hour, it can take as long as a day to produce even a simple plastic shape representing a toaster in one of todayâ„¢s solid-freeform fabrication systems. And the systems are difficult to use, requiring a fair amount of specialized knowledge. Plus, they are very costly.
2. Researchers must investigate numerous material-compatibility issues and eventually settle on a compact set of multifunctional materials.
3. We need to develop standard file formats to specify multimaterial objects so people can freely exchange design blueprints, just as the Adobe Postscript standard was developed to communicate with laser printers.
4. Difficult to work with the commercial software needed to tell the tools when to apply, say plastic on one layer and metal on the next and so on.
Limitations
Additive fabbers are generally limited in accuracy and resolution to about 0.1 mm (0.004 inch), although better results can be obtained by experienced operators or with some experimental techniques. Although fabbers are often much faster than alternative methods, they are not instantaneous, and sizable projects can run for days to be produced. Moreover, the maximum size that can be built in a single run of the largest additive fabbers is limited to less than half a cubic meter (a few cubic feet). Materials selection is also a limitation of the currently available machines. The commonly available materials include acrylics, epoxies, urethanes, and ABS, as well as wax for investment casting masters. Specialty materials also available include artificial wood and specially formulated ceramics, metallic alloys, and metallic composites. Finally, one must recognize that fabbers are still highly technical devices, requiring trained personnel and often industrial environmental controls for their use
11. APPLICATIONS
Commercial applications of fabbers are many and large. Some people have described the machines as 3-dimensional Xerox machines, or 3-D faxes. Indeed, both duplication and remote transmission of 3-dimensional geometries have been demonstrated using currently available machines.
The applications of fabbers fall into five basic categories:
- Direct, low-volume production of products or parts
- Industrial models and prototypes
- Copy tooling, such as molds and mold patterns
- Imaging of scientific, mathematical, statistical, medical, and other types of 3-D data
- Computer sculpture
ENGINEERING APPLICATIONS
Numerous supports to engineering applications which is given as follows. Electronic maker Logitech Inc., in Fremont, Calif., used a solid-freeform machine from Stratasys Inc., in Eden Prairie, Minn., to make an ABS prototype of its Bluetooth headset and then attached weights to the boom microphone to test the design for strength. Another Stratasys customer, Diebold Inc., in North Canton, Ohio, builds automated teller machine prototypes made of ABS or polycarbonate and tests their endurance in rain, sleet, snow, and extreme temperatures.
It has huge implications on engineers, designers, and distributors. Manufacturing, at least for things that could be fabbed, would be divorced from rigid corporate control, spawning new classes of independent designers. Much of the stock and delivery costs associated with conventional manufacturing would be eliminated. And with appropriate software, a product could be customized, enabling a system of bespoke production almost inconceivable today.

MEDICAL FIELD

Though much of the current hype surrounding fabbers centers on the practically endless possibilities for home use, the first commercial success for multimaterial rapid prototyping might be synthetic implants for medical applications. Nowhere is there a greater need for unique, custom objects, which would be tailored to patient dimensions. But why stop at synthetic implants? Cornell colleagues Lawrence Bonassar and Daniel L.Cohen are developing the materials to print 3-D replacement
Bone and cartilage implants constructed from the patientâ„¢s original cells. Using a CT scan or MRI, the machine would form the implants into the desired shape with the correct distribution of the patientâ„¢s cells. Such implants would be less likely to be rejected or to wear out.

ALLOWS REINTRODUCTION OF PHYSICAL MODELS IN AN INTUITIVE WAY

It is possible today to download designs for physical objects from the Web. Visitors to Cornell Universityâ„¢s online museum of kinematic mechanisms are beginning to discover its exhibits of more than 300 historical models of 19th-century machines. Equipped with a rapid-prototyping machine (many universities have at least one), cyber museum patrons can download designs from http://kmoddl.library.cornell.edu/ and print their own preassembled, detailed, functional replicas of machines that are object lessons in the geometry of pure motion.

FINE ARTS
Michelangelo achieved extraordinary control of his work by chipping marble away a layer at a time to obtain the precise form he had envisioned. His sculpture of David took three years to carve from a nineteen foot block of stone in this way. Many of his later unfinished sculptures which were made using the same technique give strong impressions of objects formed by stereo lithography caught in the moment of rising from a vat of resin, but hardened and frozen in time. While this was certainly not a rapid or an additive process, it is a multi-degree of freedom layered fabrication technique conceptually similar to some forms of modern rapid prototyping technology.
Today, layered fabrication is being used by an increasing number of artists to build a wide variety of sculptural objects. Some of these works are realistic and representational while others are abstract. The abstract objects can be the result of pure imagination and artistic free will, or may be derived solely from mathematics or computation. Some of the works created with rapid prototyping may not have been possible to make any other way.

JEWELRY DESIGN
Jewelry and the related arts have been particularly affected. Some systems manufacturers, such as Meiko in Japan and Solidscape (formerly Sanders) in the US, have concentrated on this application. There are also service bureaus and university programs which emphasize the design and manufacture of jewelry using rapid prototyping technology. The output of a rapid prototyping system is most often used as a pattern for lost-wax, or other types of casting methods in jewelry manufacture. Direct manufacture of jewelry is also a long-term possibility, however. While precious materials are not yet possible for direct output, a few artists are beginning to explore the use of the existing materials of processes such as selective laser sintering and stereo lithography as final media.
The Apollo program put men on the Moon for the first time. But it has not led to a further human presence in space because of the exorbitant expense of transporting materials off of Earth. Fabbers will drastically reduce the volume of material that needs to be transported and so will make human habitation of space practical for the first time in history.
FUTURE VISION
Digital manufacturing is the 21st-century way to make products and it will render much of what we know about 20th-century industry obsolete. In digital manufacturing, products are made from a computerized description, much as a digital document is output from a computer printer. Digital manufacturing got its start in the 20th century with CNC machining and rapid prototyping technologies, but its ultimate reach is much, much farther. In coming decades we will find people ordering products on the Internet and having those products delivered to them via self-contained personal factories directly into their homes or offices. Digital manufacturing produces real physical products from digital information.
The following present a vision of the future of fabber technologies and how they will impact the way people live, work, and play.
- Napster Fabbing ” Internet Delivery of Physical Products, about the marriage of fabbers with the peer-to-peer Internet to provide a radical new means of product distribution.
- Atoms from Bits: The Digital Revolution in Manufacturing, presenting the radical future of fabbers in the home and office, and how this will change the world.
- The Household Fabricator describes a residential subdivision built in 2008, where the homes have a fabricator room, with fab materials supplied by underground pneumatic tubes.
- The Origins and Direction of the Fabricator Revolution, the farthest-reaching discussion of future fabbers, including accretive fabrication, modeled on the growth of biological systems.
- Using Fabricators to Reduce Space Transportation Costs explains how fabbers are the critical element that will finally make space habitation feasible for the first time in history.
- The Personal Factory ,that is people using fabbers at work and at home.

CONCLUSION
The ultimate vision of personal fabbers is for people to download designs from the web and print the objects in the comfort of their own homes. While ubiquitous fabbers are still off in the future, it is possible today to download designs for physical objects from the web. The researchers have been successful in developing the power source and actuators of a robot. Thus it will not be a long time to see realization of engineering design, made exclusively inside home.
We are very lucky to find ourselves with the privilege of participating in the birth of a new freedom for humankind, the individual freedom to create tangible solid objects at will, brought about by automated fabrication. As a commercial technology, additive fabricators are less than a decade old on Earth. The various methods are undergoing very rapid refinement and improvement. These methods present new possibilities for building up objects from celestially available materials. This new capability will allow explorers to venture forth with fabricators to build their homesteads and their industrial facilities. It has long been recognized that machines with such capability would be necessary to really make space settlement feasible. It may be that fabricators will be the breakthrough that finally cracks the barrier to space habitation.
REFERENCE
wikipidea.org
fabber.com
ennex.org

CONTENTS
1. ABSTRACT
2. INTRODUCTION
3. CONCEPT OF FABBER
4. HISTORY OF FABBER
5. STEPS INVOLVED IN FABBING
6. PROCESSES
7. TOOLS OF DIGITAL MANUFACTURING
8. FABBERS AND THE INTERNET
9. ADVANTAGES
10. CHALLENGES
11. APPLICATIONS
12. FUTURE VISION
13. CONCLUSION
14. REFERENCES