Articles About Rapid Prototyping

COLOR
copyright © Michael Rees 1998

“As RP processes become more refined, so the prospect of functional
prototyping extends into mainstream fabrication. Already in some cases we
don't just use these machines to make prototypes but to make real products.
CAD systems also have greater capability for realism which we want to transfer into
physical forms with equal ease. “

Dr. Ian Gibson, University of Hong Kong

“Color is over analyzed and under-appreciated, yet it is the nuance of communication. We know the generalities of a thing through its form, but we come to know the thing itself through color.”

From “Color in Black and White” by Jack Rees, Architect.

This is a speculative article about color and rapid prototyping. Currently there are no variable multiple color technologies available in rapid prototyping although there is at least one patent which develops photo resolution color. Color has been put on the back burner in deference to rapid tooling, materials, and the development of desktop modelers. Rapid prototyping’s greatest asset, namely the visualization of complex models, has been overlooked a little in favor of functional models. And yet in many areas, a rp model cannot compete with some technologies because of the lack of precision. The relative simplicity of a rp machine (compared with creating tooling paths) again makes it ripe for the production of visualization models. If a picture is worth a thousand words and a model a thousand document: rapid color visualization is almost priceless.

Color has a major role to play in the further development of rapid prototyping as a communications media. Color is such a strong communicator that no major mainstream media is without it. As the market for rp sags, new, broader, popular markets must be aggressively developed. If the maturation of numerous technologies from black and white to color is any lesson (color TV, film, video, printing), this lesson might suggest that developing color is the next important step for broadening the market for rapid prototyping.

It has been difficult to fix the market for variable color rapid prototyping. There is no market segment calling out for color with dollars in hand to support its development. As Marshall Burns, of Ennex Corporation has pointed out, “The market for fabbers is huge and so far we’ve only scratched the surface. Most of the market for color is in the rest of the market that hasn’t been scratched yet.” A currently pending patent application details color enhancements to Burns' 1996 patent on "Offset Fabrication”. Currently Ennex is working to bring the Genie Studio Fabber to market, an office compatible, desktop modeler.

Rapid Prototyping, most broadly defined, is a communications tool between experts and non-experts alike. It can tell volumes about the nature of a design. Literally, to hold a part is to communicate complex concepts instantly. Feeling the weight and texture of a part is important to understanding it. The use of multiple colors in a model offers even broader possibility.

Several companies offer some type of variable single color models or bi-color models. Stratasys and Z Corporation offer variable single color models, while Stratasys and 3D systems offer bi-color models. (Several companies offer different materials, hence different colors, but the intention of those materials are not related to color as a communications device.) No company currently offers photo-resolution color in a single model. To many that use rapid prototyping, color isn’t even a consideration. The fact that rapid prototyping has yet to develop photo-resolution color is indicative that it is far from conceiving itself as a mainstream communication media.

Color Sells, Color Communicates

So many scientific and marketing studies have been done about color that it is almost impossible to weed through them. Color has a magnetic effect on people, particularly in a consumer situation. Some colors in a product sell immediately while other colors languish on the shelves. In a more pragmatic application, colored maps are essential to developing thickly layered information in graphical format. Again, it is so basic to the way that we understand maps its difficult to conceptualize a landscape without it. And colors immediately convey qualities. It is so much a part of our makeup that it has permeated our language. “Feeling Blue”, “seeing red”, and “in the green” have immediate associations that we are all familiar with. Finally, imagine a CAD program that would be limited only to shades of grey. The grey modeling screen would be unreadable.

Color and Rapid Prototyping

While everyone has agreed that material development, rapid manufacture, and rapid tooling are priorities for future development, people have been generally mixed about desktop modeling. Somehow, it represents a shift in engineering culture that is difficult to justify. The industry has functioned for so long on the edge of product development that it’s almost too easy to make models. This is akin to a math whiz who refuses to use a calculator—“I know it in my head already, why waste the models?” Although many wouldn’t think twice about printing proof documents or 2d visualizations of CAD designs, there is some hesitation about committing to form. Perhaps this is a trickle down effect from the enormous commitment it takes to produce injection molds. Perhaps it is beneath the expertise of those who have delivered molds accurately again and again. Or perhaps the powerful communication abilities of rapid prototyping are not fully appreciated.

When asked about color in models many engineers have stared back blankly, “What would you need that for?”

“One of the most exciting possibilities of a full color model is in the
stress analysis field. Currently, after running a finite analysis,
a color plot of various cross sections are printed with the colors
showing the relative stresses in each area. Can you imagine the clarity
that would result from being able to see the stress on the entire part
at once??!!!” Chad L Buchanan, Supervisor –RP and Model Shop at Cummins Diesel Engine

Color is a quality of rapid prototyping that would complete it as a mature communications tool. A fully colored model is both a picture and an object and contains all the information of both.

"In manufacturing, color helps designers test working mechanical
assemblies," said Terry Wohlers of Wohlers Associates, Inc. "Envision 50
pieces assembled, all in a single color, versus the same pieces in
different colors," he explained. "What's more, RP models are used
frequently to propose new concepts and gain support from others when
developing new product ideas. Color is compelling and more accurately
communicates these ideas to others," Wohlers said.

Artists who've learned about this technology usually ask "Can it do color?" This is probably more a result of artist culture than any peculiar genius. Color is the language of the arts. It is arguably its most important aspect.

Back in 1984, Norman Kinzie turned from architect to entrepreneur. From a background of moonlight model making, he quickly focused on finding out how new digital technologies would revolutionize the craft and assist architects in design and presentation. The territory was untouched, so in 1987 he was able to apply for the first, ever, patent on digital methods of fabricating colored shapes. In 1988 he coined the term "Three Dimensional Printing" and distributed a paper by that name to several dozen corporations. Included in this pioneering paper were the first public disclosure of key methods of lamination, ranging from "cut-on-the-stack" lamination, "bonded and subdivided support shell," "edge coloration," and "release sheet" layer handling. His 1991 patent contains broad claims on lamination -including uncolored methods that are in use today. Contrary to the wisdom of recent years, however, his patent emphasis is clearly on colored modeling. From Kinzie's point of view, that was the challenge. After all, CNC milling and laser cutting were already doing remarkable things for fabrication of shapes. Kinzie wondered, “Who would pay for layer-by-layer fabrication if it didn't provide a completely finished product?”

Perhaps it was Kinzie's unique perspective as an architect in an engineer’s discipline that helped him to see the importance of color.

Full, photo-resolution color models, would be able to contain color and pattern with as much variety as a 2d printer, and could have notes, photographs, patterns, and solid colors printed directly on the model (fig 1). Developing color may yield other important results. As materials are selectively applied in areas of the model to make different colors, the same mindset could imagine materials applied selectively towards greater strength characteristics and variations of material characteristics.

In a recent poll on the Rapid Prototyping Mailing List, the results were in favor of color in rp models. Of the respondents, 83% stated they would use color if it were the same price as a typical rp model. 68% stated that they would use color even if it were 20% more expensive than a typical rp model. In another question, 84 % of the respondents used rp models to propose ideas to other experts and 75% used them to propose ideas to non-experts.

The development of full color models will eventually take place. Terry Wohlers states, "Three RP system manufacturers -- 3D Systems, Sanders Prototyping, and Z Corp. -- have proven that ink jet is a viable technology for printing objects in 3D space. For many years, it's been possible to print color
using ink jet technology, so there's little technical reason why we can't produce RP models in multiple colors." Other researchers have proven the concept to the satisfaction of proceeding with a beta machine for color. The major hurdle does not reside in hardware at all; rather it is a problem of creating a file format that can hold color information in the slice. Some have calculated the size of a colored file as an order of magnitude larger than the current STL standard. Evidently the STL format will not hold color information.

Kinzie’s thoughts ring prophetically. If shape is already mastered in the industry, why not add color to the end of creating a finished model. Color adds characteristics that will benefit the development of rapid manufacturing. Who will buy a monochrome part over a fully colored, graphic model with logos and all?

There is one other important aspect to colored models. As environmental regulations of paints and lacquers become more restrictive, many labs will not be able to use high solvent paints in finishing models. “I cannot have any type of paint or paint supply in my lab at all. This puts me at a serious disadvantage in competing with service bureaus outside the company. With that said, what would it be worth to compete with the outside world? I would guess that it would be worth more than 20% of the cost of typical models today! Bring on the color!” Roger Spielman, Lead Engineer. Rocketdyne Rapid Prototype Center, The Boeing Company.

The applications and benefits for color in rapid prototyping are so varied that all of its ramifications have yet to be explored. If rapid prototyping is to assume its mantel as a more popular communications media it will develop sophisticated color abilities.

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Concept Modelers
copyright © Michael Rees 1998

Concept modelers are an exciting development in Rapid Prototyping. There are several companies which offer these modelers and several more in development. Companies with commercial products include Bpm's Personal Modeler 2100, Helisys LOM 1015H, Sanders Prototyping Inc.'s Model Maker II Stratasys's Genisys, Z Corporations' 3d printer, 3d systems Actua 2100, and I would include a variety of desktop CNC(computer numerical control) mills. some of these machines are not practical in the office environment but deserve inclusion. Some of these machines offer push button convenience and others employ intermediary digital processing. The cost of these machines range between US $1200 to US $100,000. with an average somewhere around US $60,000.

Considerations

As with all equipment each machine has its strengths and weaknesses. Typically, more speed means less accuracy. As well if one is considering the purchase of a machine, one should carefully consider the extra costs: consumables and the customer support agreements that in some cases are mandatory. As well, a company needs to consider their needs before committing to one technology or another. It is preferable to know that your customers can use this service or are willing to pay for it as part of the design process.

The intangibles of rapid prototyping can also be daunting. There are learning curves associated with machine use. More importantly, if a company does not have solid modeling in place the headaches of file conversion can destroy the time savings that rapid prototyping promises.

To insure an appropriate technology for your application consider hiring a rapid prototyping consultant. A good consultant can give you a feel for all of the costs and effort in converting your organization to rapid development. Be careful to pick one who does not rep anyone's products. Secondly, if you have internal expertise and have already concluded that concept modeling is for you, prepare a typical file and send it to all appropriate bureaus. Compare cost, speed, accuracy, maintenance. Show some parts to clients and see how they respond.

Finally, despite the promise of rapid prototyping, I've rarely seen a model which didn't need to be "benched". Benching means general preparation of the model --sanding, painting, further modeling, etc.,. Because most of the concept modelers (excluding the sanders machine) produce models that are coarse, benching can be a significant factor. One can spend 2-5 times the effort to bench the model than to make it with a modeler. Again, this is where a clear assessment of your needs and expectations for a rapid prototyping device come into play.

Some General observations about the machinery.

Most companies maintain a web site which will provide you with all the machine specifications of their products. For further information regarding a productThe Rapid Prototyping Home page <<<http://me.mech.utah.edu/home/novac/rapid.html#CONCEP>> is a good place to start. Otherwise what follows are some general observations regarding modelers and their products.

By far the machine with the greatest precision in the industry is the Sanders Prototype Inc., Model Maker II. It uses a thermoplast wax and a delivery system similar to an ink jet printer. After depositing a layer of wax, each layer is planed to thickness of .0005". This can be increased to allow for greater speed in layer formation. Because Layers can be built to .0005" stair stepping in the model is limited and creates a smoother more accurate finish. No surprise, this machine is the slowest build in the industry and has a small build envelope of 6x6x6". There is a second wax support layer which is dissolved after the part comes out of the machine. Benching the part may be unnecessary as a result of this precision. At the same time, the thermoplast wax is probably difficult to work. This is an excellent machine for small complex parts with delicate features.

The fastest machine is Z corps 3d Printer. It is a marvel to watch this machine work. Based on Massachusetts Institute of Technology's proprietary 3d printing (which is also licensed to Soligen) a binder is printed into a starch based powder. It is capable of building 8 vertical inches in 8 hours. This speed is accomplished in a build envelope that measures 8x11x8"z. Reportedly, it doesn't matter how complex or dense the part is. Layer speed is the same. After the raw part is formed it must be cleaned and either dipped in wax or soaked with an epoxy, which makes it awkward for office use. Surface resolution and part accuracy are sacrificed somewhat for this speed. If you intend to bench your parts , resolution is perhaps not as critical as the build speed. There are no supports necessary for the build because the part is suspended in powder.

Not to miss out on the development of concept modelers, rapid prototyping's giant 3d Systems introduced a concept modeler which works on multi jet modeling technology. A thermoplast wax is extruded through 96 jets forming layer after layer. This is also a fast machine and the appearance of the top surface of the parts is presentable. Supports are used for the build which make the bottom surface of the part rough and in need of finishing. The machine has a large foot print but is designed for the office environment. The maximum part size is 10x8x8". 3D systems experience in the industry and large installed base make it a compelling choice for an office modeler.

Stratsys Genisys modeler is a solid modeler with positive attributes. It employs an extrusion nozzle which delivers a high stength polyester compound. The parts are robust and can be worked to an excellent fixnish but the accuracy of the part is coarse. The build envelope is 8x8x8" and this machine is well suited to the office environment. It has a small footprint and the software for preparing models make it almost a push button technology. The support structure is easily broken off of the part. Statasys is also a strong company with a large installed base making them another good choice.

Helisys LOM technology is not directly suited for the office environment. Layer after layer of paper is laminated and then cut by laser to form the outline of the part. The by product of the laser cutting the paper is smoke. This is not a fire hazard but the smoke must be vented. Although the LOM is not billed as a concept modeler it can hold its own against any of these machines in size of part, accuracy of part, and speed of build. As well one of its distinguishing characteristics is the feel of the part. The laminated paper object gives the part a wood-like feel that is easily machinable, sanded or painted. There are no support structures but currently it is rather difficult to remove from the machine and "de-cube". Recently the company has given great attention to improving the reliability of their machinery and maintaining excellent customer relations. The cost of this machine is on the high end of the modeler spectrum, but its robust features make it considerable for purchase.

BPM's personal modeler 2100 has a lot of things going for it and a lot of things going against it. It is a 4 axis device which fires tiny thermoplast particles which land upon the appropriate layer. There is a smoothing function and because of the 4th axis the parts can be built accountable to normals. This machine is also a joy to watch but as you can imagine with the addition of the 4th axis and the smoothing function, part build is slow. Also problematic is the delicacy of the part. The company even refers to these products as "the five minute model". A typical part would not survive shipping and I have seen people crush parts quite inadvertently. After-product processes such as molding, sanding, benching are almost impossible as a result of this delicacy. The price of BPM's products are nice though (in US 28,000-US $40,000) and may have an appropriate niche in product development.

There are many companies which manufacture desktop CNC mills at various price ranges. A 3 or 4 axis CNC mill should be taken into consideration as a concept modeler. It has differences which set it off from the rapid prototyping group. Notably, these are subtractive fabricators. As a result complex geometries and undercuts are difficult to accomplish without a master fixture machinist. Also a computer file must be programmed in separate, expensive, and time consuming CAM (computer aided machining) software. There is an upside to all of this: using a CNC mill for concept models is rather more realistic in the design process. When a part must be constrained by the limitations inherent in injection molded tooling it is perhaps more appropriate to test the early models on the same technologies that will create the tooling.

Given all the inherent issues mentioned above MaxNC is a company which manufactures a desktop mill which retails for US $1200!!! There are some other nice features which can be added including digitizing and a 4th axis. This is not a push button technology. What one may save in equipment cost may be easily lost in human resources. Leave room in your rapid prototyping development to consider such an option.

FUTURE Developments

Color models, better materials, faster speeds, and inexpensive machines are all likely future developments. The modus operandi of any product development within current technology structure is to increase speed and improve materials, decrease price ,and add features. This is de riguer. As the rapid prototyping market grows, and new users emerge, one can expect these qualities to evolve.

Clearly the volume of machines manufactured is connected to the accessibility of these apparatii. As more and more companies and individuals use this technology the price can be expected to drop. This depends on consumers buying into the current price structure of rapid prototyping. It also depends upon the expansion of the industry's market identity. Clearly, there are many other uses to rapid prototyping than engineering and product development. Some inroads have been made into industries other than aerospace, automotive, medical, and toy manufacture. In isolated cases architects, sculptors, jewelry designers, and others have begun to use this. More will follow as inexpensive 3d modeling programs become affordable and the general public becomes aware of possibilities.

Currently, several machines can create models in a single solid color. Stratasys, Z Corporation, and others have this capability. On the horizon lurks some much more exciting possibilities-namely full photographic-resolution color. This would mean that whatever one has done in the cad program in regards rendering, texture, color, and photographic application would be printed in the model. Think of a Nike shoe designer who has added all sorts of colors and patterns to the cad model. Currently, the model would have to be printed and then a craftsman would add all the desired effects by hand . With a full photo-resolution modeler, the color can be directly printed to the model without intervention of a craftsman--except for further benching. This would be a 3D color photograph. Clearly, this feature would make rapid prototyping attractive to a larger community while adding valuable features in the product visualization process.

Taking the Plunge

To invest in one of these technologies today, takes careful planing and facilitation. Many companies have had great success employing visualization technologies in house and as a service for customers. A what-you-see-is-what-you-get model increases communication and decreases errors between designers and clients. Some companies enjoy positive public image as a result of employing "exciting" new technology. A bureau's culpability goes way down with the implementation of rapid prototyping. If there are mistakes in a client delivered .stl file they will show in the model. If on the other hand a file is processed, programmed, fixtured multiple times, and made on the CNC mill, there is a compounding potential for error which one must bear in house. As with any technology, new or old, it is the acumen of its implementation that insures success or failure.

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Various Uses of 3D Printing in the Film Industry
copyright © Michael Rees 1997

Computer Aided Design (CAD) is a significant part of the development of any kind of 3 dimensional form. Entire industries have CAD at the center of the health of their ability to produce and be competitive. As well, there are CAD programs developed specifically for those industries. Auto CAD has several attendant programs that work within it to ease data management, property management, and architectural and mechanical design. Links between industries that control 3 dimensional data become formed out of the need for associativity between this data. Nowhere is this more acute than in film, animation, and special effects.

The film/animation/special effects industry has yet to take advantage of the benefits that 3D Printing offer. As engineers are dissatisfied with the precision of 3D Printing for critical tolerance applications, it continues to grow as a visualization tool. The visualization ability of 3D Printing is a natural for use in animation and special effects- it is its strongest ability.

Modeling and CAD are the linqua franca for a vast communicative ability. From such programs data can be seamlessly transferred to 2D documents and images (dimensioned drawings, renderings), 3D images (vrml and open GL), 3D corporeal form (rapid prototypes and CNC machining), and 4D descriptions (animations, film, video, and vrml). Although such broad abilities are not foreign to the history of architecture, product, and art, it has never been as integrated as it is today, with the advent of CAD, CAM (computer aided manufacture), CAE (computer aided engineering), and entertainment.

Two Dimensional Imagery

From the original design and from any part in the modeling process, 2 dimensional images can be made. These 2 dimensional images are of two categories. Both are descriptive to different ends. These include plan drawings and photo rendered imagery.

The first is the creation of traditional plan drawings of the object. This communicates the intent of the designer to the ability of the builder. These types of drawings are the traditional norm for all building activities and currently have the widest use. They demand experience and are used as a communication device between experts or knowledgeable parties.

The second is the creation of a rendered photographic image. Manipulating the ability of modeling to apply textures, and various light sources, a skilled operator can create excellent photographic quality images. These are communication tools which can be used between experts in the production cycle, but can also be used to communicate information to less knowledgeable parties. They are visualization tools which help the designer, the builder, the sales team, and the consumer get a "feel" for what will be produced. Constructive illustrations such as the "exploded view" drawing fit nicely into this visualization category.

Three Dimensional Imagery, Interactivity, and Models

Of course, the modeling package excels at the development of all types of 3 dimensional communication. These communications include, work done by the original designer through the graphical user interface, the communication using vrml (virtual reality meta language) and open GL presentations of the proposed object, and the creation of corporeal 3 dimensional models.

In the graphical user interface, Designers can form and study the intricacies of models and their suitable production methods and applications. This can be done with wire frames and add on packages that simulate material qualities.

With the advent of open GL across multiple CAD packages, the models are fluidity interacted with.. Designers can now see images more closely approximated to real world qualities of light and shade (instead of going blind reading wire frames). Vrml operates in a similar fashion at far greater resolution and interactivity. These abilities are also important for the non expert to view and clarify expectations. This ability has a limited time based quality.

And finally the creation of corporeal prototypes via CNC machining (computer numerical control) and 3D Printing. Although CNC represents a completely stabile and time tested means for the construction of prototypes it is not applicable as easily as 3D Printing. 3D Printing allows an immediate visualization directly out of the modeling environment in a way which allows for complex convoluted surfaces. With some machinery it is incredibly precise, and with others very fast.

Time Based Imagery

And of course, the modeled object is easily transferred to the animation package for an almost infinite variety of communications. This can take the form of fly throughs in which the object is seen from the outside in, or of product demonstrations, in which the object is seen functioning in various environments and applications, or of sales tools, in which the object is in the context of the consumer, and for entertainment, in which the object is made as a cartoon or interacting with a real scene as a composited image. This last category is a function of the sales environment but has larger areas of subtlety, abstraction, and application.

The full use of these communication tools stemming from the modeling environment are employed in various industries at different levels of sophistication. We have all seen promotional and industrial videos and perhaps met them with a certain cynicism. That cynicism is probably the result of our common experience of film as the ultimate representation of what is capable with computer modeling and animation. And compared to the industrials, entertainment film is far more fun too.

In this industry CAD is more descriptively called 3D modeling. Its use is self evident. A 3D model is created and transferred to an animation package. There it can be made to interact with other 3d objects and scenes so that as a camera revolves around a point of view it mimics the use of camera in real space. These 3 D models can be dropped into 2 dimensional scenes and also made to interact with those scenes(compositing). Through similar means a virtual world can be formed. Models can be built from this process via CNC or 3D Printing as a means of visualization or as verification for an injection mold process. Again, the modeling package is the center of a process of communication that can create 2d images, 3d images, 3d models, and 4d animations.

The Use of 3D Printing in Film Markets.

All of the methods of representation described above are employed in the creation of movies. The least utilized are the abilities of 3D Printing.
Animation Houses have not yet been able to conceptualize the use of RP as a solution to their animation problems. At the same time, these houses often use 2d print outs and renderings as sales tools and visualization communication among themselves, to their clients and to their markets. A 3dimensional model would go further to conveying the look of the animate character. It is a stronger sales and visualization tool than 2 dimensional representations. 3D Printing's greatest strength, that of visualization and design confirmation, would fit perfectly into the animation design process.

Another aspect of this is the role RP could play in the development of the animate character. A fast 3d printer can be thought of as part of the graphical user interface. As the animator works to make a model more realistic, he would run into various "real world" problems. Perhaps the connection of the wrist to the hand is not quite right. Printing a 3d model could help in the conceptualization and solution of this process. It can improve the quality and effectiveness of the designed character. Printing a character may even extend the creative potential of the animator--it can be the spark which "tweaks" the character just a little bit further.

At the same time, if animation software were capable of solid models or airtight .iges files (many are), whatever is designed in the modeling program can become the standard file which is transferred to the after market product manufacturers. At this point the models can be utilized in test market studies and be further manipulated to create the molds for high run injected products.

There is yet another exciting potential for 3D Printing that is as yet unmined. Many movies' special effects demand the combined use of animation, compositing, real world scale models, and real world actual size models. For example, in the recent movie "Men in Black", the last scene shows the two heroes shooting down a space ship. To achieve this effect, model makers labored over 2d prints and drawings to build the space ship and then, using robotic arms, crash it into a dirt filled landscape on a sound stage. A robotic arm is used to support the large scale model (over 12' diameter) and various cameras record its crash into the landscpe. Later the film images are cleaned up in an image editing program to remove the robotic arm and make the effect look real.

There are many other examples where there is a computer model, a real model, and a "crash" model. With the arrival of Formus' Topographic Shell Fabrication (TSF), it is now possible to make very large objects in a short period of time, based on CAD/modeling data. So in the cases where there is a computer model, a real model, and a crash model, TSF can create the latter two quickly and efficiently. Mats Jansen of Formus calculates that an object which has 60 square feet of surface and fits an envelope of 10' x 5'6" x 2' z height takes 18 hours to build. The TSF process creates temporary shells for master mold or prototype creation out of silica sand which is bound by sprayed paraffin wax. Depending upon the application, a polyester prototype can be laid up by hand. The formus machine can produce several identical models, or the mold for those models, which can be plugged into subsequent shots.

Here are four very effective uses of 3D Printing or 3d printing in the film/animation process: A creative tool to increase the quality of animation design; An effective communication tool within house, to clients, and to potential markets; a large scale, time efficient model maker for special effects; and as a low run (under 100,000) production tool.

To extend this a little further, it is not hard to imagine the ways that 3D Printing could apply to computer games, or educational CD Roms. For low run CD Roms a product kit would include the software and several of the characters pictured in the CD Rom. Simultaneously, larger run products could be test marketed using low run injection molds (up to 100,000 parts) made with DTM's or 3d Systems' rapid manufacture technology. Though certainly many toys are manufactured to great precision, the lower tolerances of some products would lend themselves quite nicely to the precision of these technologies.

As the cost of concept modelers grow more in line with the cost of a single animation workstation, one would expect to see more and more animation firms taking advantage of 3D Printing. The speed, particularly of Z corporations 3D printer, is already very competitive. At an inch per hour the speed is acceptably slower than a large scale 2d ink jet printer/plotter. As with many RP systems, the parts can be nested to give greater yield per build--without slowing down the build cycle. Then there is the use of rapid manufacturing systems in concert with the original digital animation file via DTM's Rapid Tool Technology, or 3d Systems Kel Tool process. Finally, with the advent of the larger scale devices, such as Formus' TSF, the 3D Printing industry begins to extend the functionality of the original digital model into broader areas of communication and use-ability.

The illustrations attendant to this article demonstrate the relationship between the digital model and various 3d corporeal outputs.
figs 1, "Animate". The animated computer model.
fig 2 or 3 "Composite" or "Comp2". The proposed large scale model, to be built with Formus (composited image).
fig 4. The prototyped object for visualization and verification. Object size: 9"x 5"x5" z height. Kira Solid Center.

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Rapid Prototyping depends upon CAD modeling. Solid modeling packages are preferable to RP but many surface modeling packages work also. Their water tight iges files can be converted to a walled .stl file. Many have realized that the popularization of RP will depend upon useable CAD modeling programs.

To address the complexity of the CAD interface, Terry Wohlers has used the analogy of an automobile. It is an enormously complex mechanism in which multiple processes must coincide simultaneously to the desired effect. Yet to drive a car one need only operate a wheel, an accelerator pedal, and a brake. Such a simple CAD interface seems impossible if not a long way off. There are just too many variables.

There is another scenario; namely that computer users would grow in sophistication to the point that a modeling package will be just as common place as a word processor. That’s analogous to expecting someone who is at ease in several romance languages to master Chinese, quickly. They must first have the desire to do so. Do we expect the average weekend woodworker to lay down the satisfaction of working wood (speaking romance languages) in exchange for modeling cad objects (speaking Chinese) as their preferred hobby? How many RP professionals spend their free time modeling “hobby” objects for RP output?

Those who must answer to quarterly reports would have a hard time justifying advertising in a popular market for RP users. A copy shop service bureau in every major city seems a long way off. If you’ve ever tried to tell a non expert what RP is, even in the simplest terms, and then hope to convert that non expert to CAD, well its not an optimistic scenario. RP just looks arcane, something for the aerospace, automotive, and medical industries to struggle with. Something very exciting, but very remote.

There are four important developments that will contribute to a change in the esoteric aspect of RP.

? The 3D puzzle available in toy stores.

? SensAble’s haptic modeling technology (http://www.sensable.com/)

? 3D lamination printers

? Nichimen Graphics’ and Nintendo’s announcement of a 3d modeling package which will work on a Game Boy. (http://www.nichimen.com/)

SensAble’s (http://www.sensable.com/) haptic modeling technology is pretty nifty. It is an input device, much like a mouse, which employs one or two rotary arms and a pair of nimble gimbles. You can slip your finger and your thumb into the gimbles and “feel” around a 3d space. Different primitive objects can be stacked one upon the other, moved around and “felt” through the gimbles. The computer model can have texture, which is also perceivable through the gimbles. Future manifestations of the product might include a toolbox. Instead of setting up a Boolean operation between two modeled objects, you reach for the VRML drill and then drill your holes. Although way too costly for the consumer market, this technology still holds a lot of promise for future cad interfaces.

Norm Kinzie holds an important patent on 3D-lamination printing. What makes his patent distinct is the application of printed information in the model. This has broad implications, including the application of full photo-resolution color. It also has the import of allowing users to print an entire model (as a normal lamination device would), to print a single layer of a model (with notes and annotations) or to print a 3D book (all of the sections of the model printed as a page, bound as a book). If such a device were inexpensive, its not hard to imagine that the normal desktop printer does double duty as a 2D/3D printer.

Finally, the most encouraging development contributing to the popularization of RP is Nichimen Graphics’ and Nintendo’s announcement of a 3D-modeling package for the game boy. WOW! Kids able to develop 3d models on their Game Boy! The potential integration is mind boggling. Both aspects of the problems of the CAD interface are solved: a CAD interface that’s simple to use and a new generation of users for whom learning another CAD program is second nature.

Take this a step further: Nintendo games allow users to replace the standard characters with custom designed characters. And a step further: some enterprising RP company encourages Nintendo’s modeler to allow .stl output for the creation of real models, more correctly toys. Or maybe a step further: a RP giant makes a strategic alliance with Nintendo to integrate 3d prototyping into their products. When you buy the Game Boy modeler, you get a coupon for one free model. Is this rapid manufacture or what?

OK, I digress. This scenario is still pretty far out. A strategic alliance between RP manufacturing and electronic gaming seems surreal. But the fact remains that if Nintendo’s modeler catches on there will be a new generation of 3D modelers for whom CAD is not a foreign language. It is just part of their daily entertainment.

There is one more un-exploited potential for RP popularization: digital film and animation effects. Two issues ago I devoted an article to those potentials. (That’s a Print: Various uses of 3d Printing in the Film Industry, Prototyping Technology International, October 1997, issue 2).

So as the RP industry sags under the weight of its growing pains-- cheer up. The future is a bright and wonderful place were RP, 3D printing, fabbing, replicating, or whatever you want to call it is part of everyone’s daily life.

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PRESS RELEASE FROM NICHIMEN GRAPHICS, INC.

Reiterating its on-going commitment to 3D software technology
      for the entertainment industry, Nichimen Graphics, Inc. today
      announced that is has further developed its leading-edge
      N-Geometry polygonal modeler and N-Paint, a 2D/3D painting
      package, for core integration into the Mario Artist Series running
      on the Nintendo 64 console.

      Out of the three modules in the Mario Artist Series, two use
      Nichimen's software technology. The first, Animation Studio (or
      Talent Maker) partially makes use of Nichimen Graphics' 3D
      Paint. The second module, Polygon Design, makes full use of
      Nichimen's optimized modeler and 3D paint.

      N-Geometry and N-Paint are the 3D modeling and 2D/3D
      painting modules of Nichimen's N-World package. In addition to
      the efficient polygonal modeler, 2D/3D paint and materials editor,
      N-World has an advanced non-linear motion editor for multiple
      skeletons, individual bones, independent scaling, with or without
      motion capture files. The photo-realistic renderer also supports
      multiple rendering algorithms. N-World is predominantly used for
      developing games for Sony PlayStation, Sega Saturn, Nintendo
      64, PC, the Web, and location-based entertainment (LBE), due
      to the rapid production flow that it provides.

      By reducing the memory footprint of what is essentially
      N-Geometry and N-Paint 3D, Nichimen was able to provide
      Nintendo with a full 3D modeling & 3D paint system which is less
      than 1MB in size, and uses even less RAM to operate.

      The modeler, as with N-Geometry, is based on a unique
      winged-edged database system which prevents any errors in the
      modeling process and, as such, makes it a productive package for
      3D model creation when used in conjunction with the 3D paint
      package. Because of its ease of use, this system was felt to be the
      most suited for the Mario Artist Series due to the wide age group
      of Nintendo 64 owners. It will now allow both young and old to
      express their creativity in a way that has been unavailable until
      now.

      Users will be able to create complex object faces without errors
      (such as inverted normals) and then use the 3D paint to color their
      creations. By having a full-featured modeler and paint, users will
      be able to create objects and characters, with all the essential
      functions of N-Geometry and N-Paint 3D. In addition, the paint
      system will allow users to make use of both opaque and
      transparent brushes of a variety of sizes and shapes to paint
      directly onto the 3D faces and objects. With an intuitive way of
      working with color and objects, Nichimen clearly shows that its
      tools are addressing the needs of the industry.

      This latest addition to Nichimen's list of achievements marks a
      breakthrough in the industry for providing next generation
      software tools for 3D modeling and 3D painting that are truly
      integrated. The modeler and 3D paint core developed for
      Nintendo is based on the current award winning system used by
      Nichimen's N-World, the most robust 3D content creation and
      animation software used by game developers and entertainment
      production houses today.

About Nichimen

      Nichimen Graphics is a leading supplier of 3D graphics software
      for game development and interactive entertainment. Its software
      has been used to produce such hit games as Super Mario 64 by
      Nintendo, Final Fantasy VII by Square Co., Ltd., and MediEvil
      by Sony Computer Entertainment Europe -Cambridge Studios.

      Nichimen Graphics focuses its efforts on supporting the interactive
      content market, providing developers with the industry's most
      open system and leading-edge modeling and animation technology
      with unparalleled customer support. The company's suite of
      packages is truly integrated, dramatically simplifying game content
      generation. Nichimen Graphics Inc. is owned by Nichimen
      Corporation of Japan, a $62.5 billion trading company.

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