Rapid prototyping: where the services are.

Rapid prototyping (RP) service bureaus, those firms that hire out their modeling systems and related engineering expertise, make it a whole lot easier to develop representational parts when speed counts. As the accompanying directory shows, a varied lot of RP technologies has become available on a service-bureau basis--a real boon to smaller manufacturers unwilling to plunk down the money for their own systems.

Beyond expanding their networks of authorized service bureaus, some of the domestic vendors of RP systems have made recent technological improvements to make their systems more flexible, affordable, or closer to the ideal of producing parts that not only look but act like the finished product.

|SOLID-GROUND' CURING

Cubital Ltd. of Troy, Mich., recently enlisted two more service bureaus for its Solider 5600 "solid-ground-curing" system, which builds models from layers of uv-cured, liquid photopolymers (see PT, Jan. '91, p. 17). The approach differs from stereolithography in that the model is embedded in solid wax for support while it is being constructed. To define each layer, the process uses a "mask" that controls the curing of a liquid photo-resin by exposing only portions of the resin to a flash of uv light.

For the sake of adaptability to different sized parts, the company recently introduced new software that allows users to employ smaller portions of the Solider 5600's work envelope. Called Flexi-Volume, the software allows adjustments in the workspace length between 8 and 20 in. for part volumes from less than 56 cu. in to 5600 cu. in. (CIRCLE 18)

The newest Solider 5600 user, meanwhile, announced plans to operate its RP service bureau on a global basis. General Pattern Inc. has added the system to its business as part of a larger plan to create a world-wide "plastics foundry," according to president Dennis Reiland. Already, General Pattern has opened offices in Switzerland and Israel. From the field, the company would receive CAD files by modem and then produce prototype parts or tooling to customer requirements. Ultimately, the company plans to install four advanced RP systems. For its first machine, it chose the Solider 5600 after dissatisfaction with the dimensional stability of stereolithography parts, says Reiland. (CIRCLE 19)

SELECTIVE LASER SINTERING 

DTM Corp. has recently expanded the service-bureau network for its selective laser sintering (SLS) technology, adding five more bureaus to the one it operates at its Austin, Texas, headquarters. According to marketing communications manager Kent Nutt, a sixth firm is on the verge of claiming DTM's last remaining territory, a Midwestern area centered in Chicago. DTM's service bureaus all use the company's Sinterstation 2000, which employs a laser to sinter powdered polymers in layers that correspond to cross-sections of the finished model. The Sinterstation 2000 works with nylon and polycarbonate to allow functional testing, or it can use wax to produce limited-run tooling (PT, Jan. '90, p. 23; June '91, p. 46). DTM recently entered into an agreement with Japan's Sumitomo Group, a leading materials supplier that will serve as DTM's Asian service bureau and distributor. The two companies eventually will work together to develop new SLS materials. (CIRCLE 20)

FUSED-DEPOSITION MODELING

Stratasys Inc. of Eden Prairie, Minn., likewise continues to develop a service-bureau program for its fused-deposition modeling (FDM) systems, which build parts layer by layer from thermoplastic filament through an extrusion and lamination process (PT, Aug. '90, p. 50).

The company also recently introduced a new low-cost modeling system. Called the FDM 1000. it's a $50,000 benchtop model supported by a Silicon Graphics Iris workstation and operating on Stratasys's $7000 Quick-Slice software. Despite the unit's accessible price, the company doesn't expect it to displace any of the service bureaus since most of them provide value-added engineering services that go beyond simply producing parts on the RP system. And many customers use service bureaus as a way to try out RP systems before they buy, notes marketing director Mary Stanley. (CIRCLE 21)

LAMINATED OBJECT MANUFACTURING 

Helisys of Torrance, Calf., announced recently that it has shipped its 32nd system, including some to new service bureaus. The company's laminated-object manufacturing (LOM) systems build models from layered sheets of plastic, paper or composite: A laser cuts each successive layer after it has been bonded to previous ones (PT, June '91, p. 45).

Earlier this year, the company rolled out an upgrade package to improve the system's mechanical performance. The improvements include a new motor-control system with closed-loop encoder feedback, a redesigned laser-delivery system, a visible-light laser-beam alignment system, and a new software system running under Windows NT. (CIRCLE 22)

STEREOLITHOGRAPHY

As for the only domestic supplier of stereolithography systems, 3D Systems Inc. of Valencia, Calif., declines to disclose the names of service bureaus using its technology. "We prefer all requests to go through our company," explains marketing specialist Amy Hendrickson, adding that 3D will then recommend the most appropriate service bureau for the job. She notes that this strategy also helps 3D keep close tabs on potential customers and system users. (CIRCLE 23) DuPont Imaging Systems of New Castle, Del., which makes a line of stereolithography resins under the Somos name, did contribute to the list with the names of service bureaus it supplies.