Hamilton Standard

QuickCast flight-ready hardware launches Hamilton Standard's success in America's Space Station program.

The Challenge
Putting a Space Station into orbit is the fantasy that dreams were made of 20 years ago. Today, however, with the combined efforts of NASA, Boeing, Hamilton Standard and other subcontractors, such a dream will become reality within the next 10 years.

Hamilton Standard Space Systems International Inc. is charged with the development, testing and final manufacture of the temperature/humidity control system and avionics system fans of the Space Station. The Space Systems International "Fan Team" has spent two years developing and testing rapid prototyping (RP) alternatives to meet cost, budget and performance challenges of its new fan designs.

The Results
Within two years, the Fan Team has taken a 3-D solid modeling system from models used exclusively for show-and-tell to the manufacturing of space-flight-quality hardware. Their most recent efforts demonstrate that flight-ready hardware castings can be readily produced using 3D's QuickCast technology, slashing production schedules by five months or more while realizing "significant cost savings" since no hard tooling is required.

After exploring alternative RP methods for producing investment casting patterns, the Fan Team unanimously concluded that stereolithography (SL) QuickCast patterns were the finest to date in terms of dimensional conformity and surface finish. Moreover, the team enjoyed 100% casting yield in their very first QuickCast investment casting trial.

The benefits already evidenced in their exploration of SL and QuickCast technology are numerous:

• SL models act as visual aids for team designers, enabling design improvement to be identified and incorporated early on
• Rapid production of investment casting patterns with high accuracy and greatly improved surface finish
• Eliminates hard tooling and associated high costs of tooling re-work
• Accelerates product development schedules by more than six months
• "Paperless manufacturing" is realized -- up front tolerance studies are eliminated and formal drawings created after the hardware has actually been tested
• The same three-dimensional databases used for SL manufacturing are also being used in other components to create post-processing files for 5-axis milling centers

The Process
Hamilton Standard's application of QuickCast took place in their development of a fan for the avionics cooling package. 3-D CATIA solid model files were developed at Space Systems International for each of the three housings that make up the fan assembly. The data was then provided to United Technologies' Rapid Prototype Development Center at Pratt & Whitney for production of the stereolithography parts.

For Space Systems International, investment casting using 3D's QuickCast technology presented a new RP technology frontier. Unsure how the SL 5180 resin used for QuickCast parts would perform in the casting process, the Fan Team turned to Texas Instruments and neighboring foundry, Solidiform, members of 3D's earlier QuickCast beta program. Team members visited both facilities to research the new casting technique. Reasonably assured of its success, three SL parts were provided to Solidiform for casting. Three aluminum castings were subsequently produced which met all of the requirements of MIL-STD-21180 Grade B on the first pour. These castings will be used to complete the development hardware portion of the project.

Explains Bob Davis, "During development testing we identify design changes needed to maximize our fan efficiency. We have already been able to predict what flight quality hardware will look like. Even today, traditional methods mean a 30-week lead time to get a hard tool casting, and that casting is only as good as the tooling supplier's interpretation of the 2-D CAD drawing. With QuickCast we were able to complete castings of two housings in less time than it would have traditionally taken to get the drawings alone."

The Tools

• CATIA 3-D solid modeling software
• SLA 500 with Cibatool SL 5180 resin
• QuickCast software release 1.0
• Standard foundry investment casting procedures for QuickCast

Company Profile
Headquartered in Windsor Locks, Connecticut, U.S.A., Hamilton Standard is a division of United Technologies Corporation. The company is a fully integrated supplier of aerospace systems and equipment, controls and accessories. Its worldwide markets are commercial, regional and general aviation; military aviation; space and aftermarket services. An early developer of space life-support technology, the company has contributed to the growing U.S. space program for more than three decades.