Now that “rapid prototyping” is an accepted process, the next logical step is to emphasize the use of some of this equipment for manufacturing. No one agrees on the definitions of various prototyping and manufacturing terms –rapid, digital, direct, additive, e-, and so on. Regardless of the definition, the process of going from CAD drawing to end-use part continues to get faster. It is common to find 3D printers, FDM, SLS, SLA, polyjet, and metal casting equipment making end use parts for medical, dental, aerospace, and consumer product industries, among others. Continuing developments in metal and resin materials are making it easier to go to production.

Newer materials, like EOS NickelAlloy IN718 let you develop prototypes that can become production units.

Of course, when we say production, the question is — how many parts? The range is from 1 to several thousand. Noted Abe Reichental, CEO, 3D Systems Corp., “We see the industry moving more into the manufacturing arena. Over 40% of our activity is derived from direct and indirect manufacturing application of end use parts. This is a significant shift in the business model and in our focus and dedication in application now and in the future.”

Selective laser sintering (SLS) equipment produces aerospace parts used on the V-22 Osprey twin tilt-rotor airplane/helicopter, for example. These are production parts. The benefit is lower weight and dimensional consistency. Some parts for military aircraft are also made of SLS precision plastic material; again to save weight.

“Prototyping, while still important, has changed with the amount of direct manufacturing increasing,” continued Reichental. “The productivity and cost effectiveness in build envelope sizes, for example, has enabled a transition from traditional manufacturing methods to additive manufacturing methods without giving up any of the traditional benefits. In fact, additive manufacturing has added to the benefits by reducing labor, inventory, and inflexibility. We have enabled true mass customization and realized the dream of a flexible factory in a box.”

One trend in materials is combining different ones to create composites for both prototyping and final product.

“The use of prototyping equipment for manufacturing processes is speeding up,” agreed Frank Marangell, U.S. president and CEO of Objet, a company specializing in 3D printing. “You can print a mold and then inject resin to produce 100 parts in a day or two. But what do you call that, digital manufacturing or rapid prototyping, and does the term matter?”

Stratasys too has found that its customers are moving into the manufacturing arena. According to the company, 40% of its customers were using FDM for production several years ago. “We’re fairly confident that percentage has increased. Although most applications of our machines are still for prototypes, the growth rate of production applications is more than double that of prototyping,” said a company spokesman.

Noted Thomas Mattes, Vice President Technical Manage-ment P and Crossfunctions, EOS, “We see laser sintering being adopted more and more for the production of series parts. Nevertheless, in proportion to its potential, laser sintering is still considered too seldom for use as a manufacturing process.” Although it is very useful in the medical device industry, especially for disposable instruments in metal and plastic.

Materials are crucial, of course. The development of metals for rapid manufacturing applications continues; aluminum, cobalt, nickel, and titanium alloys are common. A big trend now is for vendors to develop prototyping materials that more closely match the end material, without the need to sacrifice properties or part performance. Noted Pedro Gonzolez, product manager, Roland DGA Corp., “Engineers can create prototypes in the same material as the final production component for actual real world testing.  Instead of limiting testing to one material, engineers can open up their testing to a few more parameters to ensure that they have designed the correct component and selected the appropriate material.”

Objet also lets you more closely match your end material. You can develop composite materials from a choice of eleven physical materials. In addition, you can produce a complete part in one step, rather than build the components for later assembly.

Subtracting subtractive?
Some vendors are looking to reverse the spread of “subtractive tools,” with the more “rapid cousins.” But subtractive is not shrinking yet.

CNC has never been viewed as quick, until recently. Continued Gonzolez, “In some applications, there is no perfect rapid prototyping solution, so subtractive rapid prototyping fills in when you need ultra smooth surfaces, tight tolerances, and a wide choice of materials.”

And, thanks to faster tool path programming, you can obtain quality metal parts in a day or two. “I view all of this prototyping equipment as CNC controlled machining,” said Brad Cleveland, president and CEO, Proto Labs. The company’s FirstCut program uses software built from the ground up to remove all the time and analysis of tool path generation. “If, in the early days, industry had the ability to generate tool paths quickly, there may have been no need to develop all of these other types of prototyping systems.”

But it depends on the geometry of the part as to which one you pick. FDM suits parts with complex geometry. But if geometry can be injection molded or machined, then time and cost become factors.

“The biggest advantage of additive processes is that they can handle almost any geometry you can imagine,” continued Cleveland. “This is not true with molding or CNC. Plus, with additive, you don’t need tooling, which is an advantage over molding. The  huge disadvantage, however, is part properties and finish.”

A printer on every desk
HP has entered the 3D printer market through its arrangement with Stratasys. The two companies co-developed the Designjet 3D unit. Available in two models and starting below $13,000, this 3D printer creates accurate models in ivory colored ABS material, while the HP Designjet Color 3D printer produces single-color parts from a selection of eight colors. Several3D printer competitors see this development as a benefit to theindustry. “The differentiator amongthese products will be the quality of the part you get,” noted Marangell.

For all printers, the price per-formance ratio is getting better. As printers drop in price, yet maintain or improve in performance, you may see vendors offering the printers for rock bottom prices, knowing that they will have a bigger margin on printer materials.

Ready for service
Several vendors have broadened their scope and now offer direct manufacturing services. 3D Systems is gearing up to produce parts to meet those customer needs that exceed an in-house investment. Said Reichental, “We entered the parts service business in a big way late last year. We see this end of the business becoming more important. In some cases, the control required for direct metal manufacture may be better handled through a service provider.”

The shift from prototyping to end-use manufacturing continues to grow.

Others are offering unique products to aid you. EOS, for example, is offering Part Property Profiles (PPPs), which are profiles with reliable values for the dimensioning of laser-sintering designs. These values cover tensile strength, elongation at break, and moduli of elasticity for the horizontal X/Y-direction. The PPPs also have standard values for the orthogonal Z-direction for additive layer processes. Profiles for Balance, Performance and Top Quality are available for all EOSINT P and FORMIGA systems, TopSpeed and Speed for the EOSINT P760 and EOSINT P395. EOS will be making the entire characteristics of the Part Property Profiles available on M-Base, a public database established by the plastics industry.

3D Systems
www.3Dsystems.com

EOS GmbH
www.eos.info

Objet Geometries Ltd.
www.objet.com

Proto Labs
www.protolabs.com

Roland Corp.
www.rolandus.com

Stratasys Inc.
www.stratasys.com

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Staying competitive can be tricky in this global marketplace. There are many companies trying to woo your business. Perhaps using a new or different rapid prototyping material can help you generate higher quality products, exceed your customers’ expectations, and grow your business.

This material has a low smoke density and toxicity, and emits no corrosive gases.

For instance, 3D Systems launched its DuraForm FR 100 material to meet the flame retardancy necessary for many potential aerospace applications. It has been formulated to reduce production of smoke and related toxic byproducts of combustion and achieve UL94 V-0 rating to meet the needs of today’s human environmental safety for many other consumer applications.

The product is well suited for injection molded plastics. You can build prototypes that withstand functional testing. You can also produce durable end-use parts without tooling, create accurate and repeatable custom parts, and possibly increase your market opportunities through plane retardancy.

The material is flame retardant and halogen and antimony free. It is FAR 25.853 non-drip and UL94 V-0 compliant, and has low smoke density and toxicity. According to 3S Systems, the product is easy to process, emits no corrosive gases, and meets aerospace smoke density and toxicity requirements.

DuraForm FR 100 is flame retardant and is ideal for generating prototype parts for testing such as these computer mouse components.

Some DuraForm Fr 100 applications include rapid manufacturing, aerospace and aircraft cabins, computers and business equipment, complex thin-walled ductwork, housings and enclosures, automotive components, and consumer goods and sporting equipment.

3D Systems
www.3dsystems.com

Resins
Epoxies Etc. announced its 70-2170 urethane casting resin as a liquid, low viscosity material for casting dimensionally stable parts. Parts made with the material have an acrylonitrile butadiene styrene (ABS) feel and appearance. The product is mercury free and does not contain TDI or 4,4-methylenebis (2-chloroaniline) (MbOCA). According to the company, the material’s low shrinkage and low viscosity facilitates the production of precision parts.

Part made with 70-2170 being removed from a metal mold.

The prototyping material offers the following properties:

• High impact resistance
• Dimensional stablility
• Fast room temperature cure
• High durometer
• Convenient mix ration
• Good machinability

The resin has a tensile strength of 7,200 psi, a hardness rate of 70 Shore D, an Izod impact strength of 1.57-ft/lb/in., and a glass transition temperature of 78°C.

Another resin material that may suit your needs is the Spectar copolyester sheet product. It comes in sheet sizes of 3/8-in. and ½-in. thicknesses for use in the medical device market. The product is available in 4-ft X 8-ft sizes off the floor; 8-in. X 10-in. hand samples are also available. Material manufacturer Spartech says the product is highly chemical resistant and non-corrosive making it a good choice for thermoforming orthopedic casts, chest protectors, neck braces, and nursery isolettes. The product is recyclable. Overages and trim can be reground and reprocessed into other non-medical products.

Specter copolyester is a thermoplastic sheet used in engineering applications and can produce complex shapes, precise details, deep draws, and compound curves without worrying about durability. It is easily formed, die-cut, and punched. The product passed ISO 10993 biocompatibility testing.

Also fairly new to the market is a resin from Ticona called Fortron 6162A7. It’s a mineral/glass-filled polyphenylene sulfide (PPS) with good flow properties for appliance, industrial, and electrical/electronic applications that require high-temperature resistant, thin-wall components.

The material is flame resistant without additives and is recognized by Underwriters Laboratories to be UL 94 V-0 for wall thicknesses down to 0.8 mm. Other features include the following:
• It has a 40% improved flow versus Fortran 6165A6.
• The Comparative Tracking Index (CTI) is greater than or equal to 175 volts.
• It rates 0 UL hot wire ignition (HWI) at 3.0 mm thickness.

The material manufacturer developed the new product in direct response to a consumer appliance maker that needed a higher-flow material to mold larger diameter parts in a multi-cavity tool. The molding conditions required an enhanced Fortron PPS grade with improved flow that could maintain the same shrinkage properties and has all the properties of the original product.

Ticona developed Fortron 6162A7 for an appliance customer that needed a higher-flow material to mold larger diameter parts in a multi-cavity tool.

The material is well suited for industrial and appliance applications such as induction heating coil plates for food warmers and electric ranges, and laboratory “cool touch” heating apparatus. The company says the product is for use in electric switches, relays, potentiometers, and other circuit carrying components.

Epoxies Etc.
www.epoxies.com

Spartech
www.spartech.com

Ticona
www.ticona.com

Applications that can benefit from the use of ABS include:

• Concept modeling
• Form, fit, function
• Design verification
• Master for RTV molding and vacuum forming
• Jigs and fixtures
• Marketing tools
• Thermoforming

Parts generated using ABS are produced within an accuracy of +/- 0.005-in. or +/- 0.0015-in./in. whichever is greater (+/- 0.127 mm or +/- 0.00015 mm/mm whichever is greater. Maximum build dimensions are 23.6 X 19.7 X 23.6-in. and 600 X 500 X 600-mm.

There is a point at which someone who doesn’t necessarily need a tractor wants to buy one anyway. This point takes a special design that’s attractive, nostalgic, and capable. The Boomer 8N tractor was meant to attract those buyers as well as those who actually need a tractor but want something with a classic look and feel.

Originally built in 1947, by 1952 more than 500,000 8N tractors were produced, and today 50% of them are still working the land. The 8N was recently updated, designed, and manufactured by Case New Holland, New Holland, Pa. The tractor was also “slightly” redesigned for the latest manufacturing capabilities and to improve ease-of-use. Some of the updates, meant to hold to the classic look of the tractor while also bringing it into the 21st century, included a redesigned hood, seat, and fenders. The hood, in particular, was drawn from the spirit and character of the original machine and married with a more modern design.

Conceptual drawings were created for the boomer 8N throughout its design cycle. This is a sample of how the hood went through several iterations before it was even sent to the design team for prototyping.

The mechanical engineering design team at Case New Holland worked closely with the industrial design team from the Fiat Automotive Style Center to hone in on the original classic details. Once the style was agreed upon, the engineers went to work building two mock-ups prior to going into full production.

Building the Mock-Ups
The Case New Holland team used Pro/E to produce the CAD drawings used in the production of the original prototypes for the retro version of the Boomer 8N. During the design cycle a variety of elements had to be prototyped and tested not only for function, but also for manufacturability. According to the design team, the hoods for the two mock-ups were the most challenging to create because they were to be a single piece rather than the multiple pieces that were used on the original tractor. To allow the hood to be removed as one piece, the new design had to incorporate the light mounting and the grill mounting. For example, the signature headlights from the original 8N were separate standalone components, where the retro version of the tractor required that they be integrated more as part of the new hood design. This helped to keep costs down, made the Boomer 8N look more streamlined, but also created a stronger, sturdier light source for the tractor.


The hood of the Boomer 8N made it through a vigorous cycle of drawings and engineering to create the single piece component.

The new design also meant that the hood would have to open and close differently than the original 8N manufactured in the 1940s. The hood hinges needed to be located so that the newly designed single piece component could be opened easily and with-out coming into contact with any of the critical engine parts while doing so. It also had to open to provide clear engine access for maintenance purposes.

The prototype for the hood was a hand lay-up fiberglass done by the expert team at Midwest Composite Technologies, Hartland, Wis. Midwest provides full CAD capabilities, rapid prototypes in either metal (DMLS) or plastic (SLS) components, FRP Fiberglass molding, and short run injection molding to its customers. Midwest can also create very large parts using their 5-axis CNC Router with an envelope of 23-ft x 10-ft x 5-ft. According to Helmut Keidl, President and CEO of Midwest Composite, “The 8N project was one of our more interesting endeavors because we were able to employ multiple processes for a single job. All components had to fit together perfectly and present the aesthetic our customer required.”

For the hand lay-up of fiber-glass parts for the hood compo-nent, engineers applied a gel coat to a cleaned and prepared mold. The first coat was cured before a second coat was applied. After this the fiberglass was laid in layers to create the needed thickness of the final part. On a large lay-up the fiberglass laminate that hangs over the edge of the mold can be trimmed using a saber saw and prepped using coarse sandpaper. While curing, the part had to be supported to maintain its shape. Once removed, the part – in this case, the Boomer 8N hood – was finished and painted to spec.

In keeping with the classic look of the original 8N, the creative team updated the seat to a self-skinning polyurethane foam for comfort.

Accuracy for the hood prototype was important because the final model not only represented a precise version of what the manufactured vehicle would look like, but it was also used to prove out the design parameters selected for the part. The Case New Holland engineering team was able to test and finalize the design after the second prototype was produced.

Most of the prototyping work for the Boomer 8N was done by Midwest Composite Technologies. According to the New Holland design team, having a supplier that understands your time restraints and cost limits is critical in ultimately producing a quality end product – on time and on budget.

Fully understanding the end product allowed Midwest to create each component of the mock-ups from the appropriate prototyping process. For example, although the hood was created using fiberglass molds, the newly designed seat was fashioned using a self-skinning polyurethane foam. Like other processes for this application, the mold was made in-house. The final product had to match the conceptual drawings from CAD, the required mechanical specs, and the aesthetic that Case New Holland wanted for the tractor. Overall, the seats were designed for comfort and utility, yet maintained the classic look of the original 8N.

According to the Case New Holland design team, working with as few vendors as possible enabled them to assure that each part was consistent with the quality and craftsmanship of all the other parts being produced. It also allowed for a smoother flow of components and less handholding. The final tractor is a testament to the quality of collaboration between the companies for this project.

Midwest Composite Technologies
www.midwestcomposite.com

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