| Top: A wheel “built” on 3D Systems’ SLA 7000 stereolithography machine. Bottom: The new Stratasys FDM 360mc uses fused deposition modeling to achieves the accuracy, repeatability, and material specifications of more expensive systems, but with less speed. |
The Society of Manufacturing Engineers’ Rapid 2008 recently attracted one of its strongest attendance totals in years, and garnered praise for its technology focus. More than 1,500 attendees participated in this annual conference and exposition. Staged May 20-22, the event took place outside of the Midwest for the first time, but a broader change of focus brought more attendees to the show floor for the latest rapid technology trends.
“Congratulations to SME for successfully bringing the Rapid Conference to a new location and in increasing exposure of Additive Fabrication to a historically, non-traditional audience (outside of greater Chicago/Detroit),” said Fred Fischer, marketing manager, Stratasys Inc. (www.stratasys.com), a provider of 3D prototyping technology.
“We believe that the [increased] attendance at Rapid 2008 validates the increasing awareness and benefits that additive fabrication is providing the design and manufacturing communities.”
Rapid 2008 conference programming included several focus areas, such as Rapid Manufacturing, Rapid Prototyping, Medical Applications, Castings, 3D Scanning, and “What’s Cool!”
Express Pattern looks ahead
During the conference, Express Pattern’s Tom Mueller presented “The Rapid Manufacturing You Didn’t Know About and How It Is Changing the Way We Manufacture Metal Components.” He provided insight to prototyping in metal manufacturing, in particular the ways that Indirect Rapid Manufacturing (IRM) is positively impacting how metal components are manufactured.
IRM uses an additive fabrication process to create an intermediate step in the manufacturing process of an end-use part. This process is already used in many industries, and the presentation illustrated that there is a lot of potential for this new alternative.
Design complexity, production volume, and incremental manufacturing costs are the three principle factors in comparing manufacturing costs of the different processes. Mueller contends that IRM is a viable alternative to machining and investment casting, and is advantageous when dealing with higher-complexity, lowervolume metal manufacturing applications.
Express Pattern (www.expresspattern.com) specializes in creating high-quality QuickCast and Thermojet investment casting patterns and functional prototype parts that are accurate, consistent, and repeatable, and have a superior surface finish. Express Pattern’s recently expanded 20,000-ft2 facility in Vernon Hills, IL, has 12 Quick- Cast stereolithography (SLA) units and nine Thermojet systems.
Employing 25 highly effective project managers, engineers, and solutions specialists, the company also attributes much of its growth to its prototyping experts, who assist Express Pattern’s customers to develop procedures that successfully and reliably process investment casting patterns and prototype production.
EOS launches new materials
EOS (www.eos.info) presented a new material for direct metal laser sintering (DMLS) at Rapid 2008. Dubbed EOS StainlessSteel PH1, it offers high hardness, very good corrosion resistance, and excellent mechanical properties, matching the traits of stainless steels currently in use in the medical and aerospace industries.
Founded in Munich in 1989, EOS GmbH is a manufacturer of laser-sintering systems. EOS of North America Inc. sells, services, supports, and markets the entire EOS line of rapid prototyping, rapid tooling, and rapid manufacturing systems. This includes solutions for plastic laser-sintering as well as direct metal laser-sintering (DMLS).
EOS StainlessSteel PH1 complements the existing EOS StainlessSteel GP1 material, which is a 17-4 stainless steel.
“We have already seen our customers achieve remarkable innovations with EOS equipment and our existing materials,” says Peter Klink, executive vice president of global sales at EOS. “We are proud to showcase our new metal offering (for) forward-thinking product developers who are extending the boundaries of their individual industries gather to evaluate new technologies.”
Dr Michael Shellabear, vice president, was a speaker at a Rapid 2008 rapid manufacturing session, detailing on quality requirements for industrial applications of DMLS.
CRP introduces New Material
Another new material for prototypes is Windform PS, a polystyrene- based material launched by CRP recently, and optimized for the selective laser-sintered disposable patterns for rapid casting. CRP’s R&D department has been involved in the rapid casting technology since 1997, and is a pioneer in high-tech casting.
In 1997, CRP (www.windform.it) began to study laser sintering for manufacturing disposable patterns using polycarbonate and Trueform materials. Although these materials were not suitable for titanium alloy pouring — because the high ash content remaining inside the shell reacted with the titanium alloys, producing porosity, and thus scrubs — they proved perfect for steel and aluminum alloys.
CRP, therefore, decided to develop new materials for rapidcasting pattern sintering, and partnered with DTM Corp. in 1998 to be the first to use rapid casting for hard-to-cast shapes, such as Formula 1 uprights and gearboxes, and alloys, such as titanium. They were first to optimize a polystyrene material for laser-sintered patterns, the CastForm.
That year, CRP also began to optimize its engineering and manufacturing processes. They studied titanium rapid casting, based on a combination of rapid prototyping (RP) technology to manufacture the disposable pattern, and investment casting with titanium alloys.
CRP has used CastForm from DTM Corp. for many years. Their R&D department built on DTM’s knowledge and experience in rapid prototyping, casting, and machining to become experts in rapid casting. This work led to CRP being recognized for its expertise in rapid casting for motor sports applications throughout the world. It was these efforts that led to the latest breakthrough, Windform PS.
Windform PS is a new polystyrene-based material able to produce complex investment casting patterns. The sintered patterns are porous in order to allow wax infiltration, making them easy to handle and finish.
Windform PS patterns can be used in typical rapid casting procedures, including autoclaves and flash firing steps, lowtemperature furnaces, and vacuum plaster casting methods. But, compared to other polystyrene materials available on the market, CRP claims the following advantages for Windform:
•Improved surface quality and details reproduction;
•Less “curling” effect on the first layers;
•Very low ash content, suitable for highly reactive alloys, such as titanium, aluminum, magnesium, steel, and nickel-based alloys.
They also claim Windform is particularly suited for the foundry and RP market, because its main applications are a) complex investment casting patterns; and b) casting with highly reactive alloys, in addition to typical cast alloys.
The casting structure is formed of an aggregate of grains, or polyhedral crystallites, which produce isotropy compensation — a solid metal that is an isotropic. Thanks to isotropy, FEM calculations are very close to the real behavior of the part.
Rapid casting with laser-sintered patterns also allows complete freedom of shape conception, needing no even supports and reducing undercut and tool path problems during CNC machining. It also allows optimization of the project to the working conditions, making it possible to create a product along its mechanical stress axes, and to obtain a perfect reproduction of all details of the RP pattern, with tolerances and surface finishing of fully machined parts that are of a very high quality.
Two direct metal laser sintering systems
3D Systems Corp. (www.3dsystems.com), a provider of 3-D modeling, rapid prototyping, and manufacturing solutions, earlier this year announced it had entered a private label arrangement with MCP Tooling Technologies. Under this agreement, 3D Systems plans for the immediate availability of the Sinterstation Pro DM100 and DM250 SLM systems, direct metal manufacturing systems that build fully dense parts for end products, prototyping, and tooling.
The DM100 and DM250 systems build metal parts using selective laser melting (SLM) technology, wherein a laser fuses metal powder into a solid, three-dimensional part in an additive, layer-bylayer process. Using CAD data, these direct metal manufacturing systems produce highly accurate, detailed parts with smooth surface quality within hours, without significant additional tooling.
DM100 and DM250 systems are said to be well suited for a broad range of medical, dental, aerospace, automotive, electronics, and military applications, as well as for tooling and conformal cooling applications that require accurate, fully dense metal parts made from a wide selection of metals.
With a quick polish to a finished part, Sinterstation Pro DM100 and DM250 SLM systems directly build parts in aluminum, titanium, stainless steel, tool steels, cobalt chrome, and Inconel. In addition to the advantages of using such a wide-range of materials, the smaller build volume of the DM100 is well suited for digital dentistry applications, while the larger build volume of the DM250 provides general-purpose flexibility and high throughput.
“We are excited that two global companies like 3D Systems and MCP Tooling Technologies are partnering to deliver these new, world-class direct metal manufacturing systems to the marketplace,” said Simon Scott, MCP’s Group Managing Director. “These systems reliably build highly complex metal parts with high resolution. With this alliance, we are expanding the reach of our manufacturing solutions and entering new markets.”
“Partnering with a best-in-class direct metal equipment supplier like MCP Tooling Technologies to create a more comprehensive family of 3D Systems-branded systems is another significant step in expanding our portfolio of rapid manufacturing solutions into functional end-use metal parts, for the benefit of our OEM customers and preferred service providers,” said Abe Reichental, 3D Systems’ president and CEO. “The private-labeled MCP SLM systems complement our existing SLS systems, enabling us to leverage our extensive global field sales, service and application engineering presence, and to fit directly into market segments that we are targeting for expansion.”