Bose Corporation

The Challenge
Bose Corporation, world leader in audio components and systems located in Framingham, Massachusetts, needed appearance parts for two different car speaker grills, one 101 mm (4 in.) diameter and the other 76 mm (3 in.) diameter, for actual road testing on an Oldsmobile Aurora.

Needing more than a stereolithography (SL) prototype, Bose approached Drew Santin, owner of Santin Engineering, and requested a short run of production parts in end-use material which included uniform texture and multiple colors to match the car interior color options. The catch? Parts needed to be delivered in exactly four weeks.

Santin determined that traditional hard tooling would take nine weeks to complete due to each part's contoured design, compound curvature parting line, and complex detail. Because of its ability to produce a textured surface finish, its greater temperature control of the tool, and its durability to guarantee a run of at least 500 parts, Santin turned to the Shaw process of rapid tooling for successful delivery of these time-sensitive parts.

The Results
These production-quality parts were delivered to Bose exactly four weeks after the day they placed the order. The plastic parts were mounted into several of the cars and successfully color matched as well as road tested for design, function, and durability.

By using the Shaw process, Santin shaved five weeks off the tooling cycle, a time savings of over 50 percent. "Even with an open schedule and every single man-hour dedicated to this project, we still would not have been able to meet our deadline using traditional tooling," says Santin.

"Rapid tooling with stereolithography was the only approach we could have taken to ensure the project's success."
                                                                           - Drew Santin, Owner
                                                                           Santin Engineering

The Process
After receiving the file transfer from Bose, Santin set to work building the master part pattern on an SLA 250 system. After the SL part was completed, rubber impressions were made of the part using flexible silicone rubber, creating a core and cavity mold. Santin then removed the SL part and sent the rubber mold impressions to a local foundry where ceramic material was poured over each impression, creating ceramic part patterns. Once the ceramic had cured, the rubber was withdrawn. Aluminum inserts were then cast from the ceramic part patterns, finished and mounted to produce a final assembly tool.

Within days of the tool's completion date, Santin quickly shot over 500 parts in a variety of colors, and most important, in the real production material, ABS plastic.