Appliance Design - October 2007 - (Page 45)

PROTOTYPING of machines available, the material choices that are offered and subsequent turnaround times. The age of the machine is also important because an older generation machine may not have all the features of a newer machine, and may not produce as accurate a replica. For example, RedEye RPM, a Minneapolisbased business unit of Stratasys, employs 80 FDM machines to make prototypes out of production grade thermoplastics and high-resolution resins, and it can make production parts in low volumes, says RedEye RPM Product Manager Tim Thellin. One of the benefits of being a division of Stratasys, says Thellin, is the fact that they get the latest FDM equipment from their parent company and have experts in the technology. The company also builds concept models using PolyJet machinery from Israel-based Objet Geometries. In addition to rapid manufacturing, RedEye offers other services including an overnight program for parts made with ABS materials. Thellin says they dedicate 10 FDM machines to this service. “Get it to us by 4 p.m. eastern, and we will run it overnight and ship it the next day,” he says. An engine prototype built by RedEye RPM using PolyJet concept modeling technology. Know your product Knowing the bureau’s capabilities is only part of the equation. It is also important to understand exactly what the prototype needs to do, what it is made from, when it is needed, how it is to be tested, and where it is in the design cycle. “Are you at the cocktail napkin stage and you just need to see something?,” asks Grimm, “or are you about ready to pull the trigger on production and you just want to evaluate one last function of the part?” The ability to use equipment that an OEM may not have in house is one of the main advantages of a service bureau, Grimm says. Quickparts’ Hollis agrees. Hollis, who is the author of the recently released product development book, “Better Be Running! Tools to Drive Design Success,” says that his service bureau offers a slew of RP technologies including SLA, SLS, FDM, PolyJet, and CNC machining. It can also cast urethane and do sheet metal work. Selecting the appropriate process and material is the key to producing a prototype that meets the designer’s specification, he says. “The number one thing a designer must know is the purpose of the prototype,” he says. “If they just want to look at it, touch it, feel it, then www.applianceDESIGN.com they might want to pick a process such as SLA that will give you a part, but not as much functionality. But, for a part with more functionality such as a handle, SLA might not be as good of a choice because the part produced might be too brittle and it could break. FDM, on the other hand, which produces more durable parts, could be the ideal solution for that.” In some cases, multiple technologies are needed if the part is going to take different paths. Some of the parts may go to marketing and need to look good for aesthetic or ergonomic evaluation, while other parts might need to go to a testing facility for functional testing. In this case, one part maybe can be made on a 3D printer, while the part to be tested could be made on an FDM machine. Testing a prototype means that its properties must match the properties required in the end use of the production part. Some machines such as FDM equipment use plastic materials that are very much like the thermoplastic materials that are used by the injection molder, says Thellin. However, just because some materials do not have all of the properties of a thermoplastic does not mean the prototypes negate the part’s usefulness. Mueller of Express Pattern points to SL resins that cannot exactly duplicate injection-molded thermoplastics, but notes that, nonetheless, given the advancements in the resins, parts made from them can still predict the performance of injectionmolded parts. “We can’t match all of the properties, but if we are fairly specific about what kinds of situations, it generally narrows down the properties to two or three key properties,” he says. According to Mueller, properties that need to be tested are usually such things as stiffness, coefficient of thermal expansion, which is the expansion a part will undergo when exposed to excessive heat, or heat deflection temperature, which is the temperature at which the material softens enough to allow excessive deflection. Understanding these parameters, Mueller says that, “We can get a material that is reasonably close, then we have a material that we can test and draw conclusions as to how well the part will work.” < For more information, enter numbers: Dimension 3D Printing Group. . . . . . . . . . . . . . . . . . . . .309 Or email: jroitenberg@dimensionprinting.com Express Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .310 Or email: tmueller@expresspattern.com Objet Geometries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311 Or email: info@2objet.com Quickparts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .312 Or email: Rpowell@quickparts.com RedEye RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .313 Or email: godigital@redeyerpm.com Stratasys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Or email: info@stratasys.com 3D Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .315 Or email: moreinfo@3dsystems.com applianceDESIGN October 2007 45 http://www.appliancedesign.com

Table of Contents Feed for the Digital Edition of Appliance Design - October 2007

Contents Editorial Shipments/Forecasts News Watch Applying Powder Coatings to Plastic Parts is No Longer a Pipe Dream New Technology Platform Provides the Ability for a single IC to Control Two- Motors in a Single Appliance, Simplifying Motor Control Design Advanced Motor-Control Techniques have Become More Accessible to a Wider Array of Appliances, Helping to Improve Efficiency and Reduce Noise Adding USB Host Capability to Appliances Permits In-Field Programming and Acquisition of Test Data ZigBee Modules Make it Easier to Design Wireless Connectivity into Applications New Concepts such as Rapid Tooling and Rapid Injection Molding Provide Stepping Stones Between Prototyping and Full Scale Production A Number of Factors and New Developments Affect the Decision on Whether to Build Prototypes In-House or Outsource to a Service Bureau DesignMart Advertiser’s Index Association Report: CEA

Appliance Design - October 2007

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.