Www Americanmachinist Com Content Site304 Articles 08 01 2005 9886casebooks02 00000003702
Www Americanmachinist Com Content Site304 Articles 08 01 2005 9886casebooks02 00000003702
Www Americanmachinist Com Content Site304 Articles 08 01 2005 9886casebooks02 00000003702
Www Americanmachinist Com Content Site304 Articles 08 01 2005 9886casebooks02 00000003702
Www Americanmachinist Com Content Site304 Articles 08 01 2005 9886casebooks02 00000003702

Castings help shop weather prototype project

Aug. 5, 2005
Honeywell Aerospace Electronic Systems (AES) needed aluminum pedestals for its RDR 4000 antenna weather-radar system in eight weeks.

Instead of machining from solid, ICI produced a production-quality first article weather radar-system pedestal from a casting that met all Honeywell's form, fit, function, and metallurgical requirements and its delivery time of eight weeks.

Honeywell Aerospace Electronic Systems (AES) needed aluminum pedestals for its RDR 4000 antenna weather-radar system in eight weeks. To meet this demanding schedule, the first prototype pedestal was machined from a 450-lb aluminum block. However, it did not meet weight requirements, and machining complexity compromised some of its features. Honeywell engineers wanted a better prototyping method, one that worked for pre-production and met the company's compressed schedule. It turned the job over to Integra-Cast (ICI), a manufacturing company that combines investment casting, machining, and assembly.

ICI produced a production-quality first article that met all form, fit, function, and metallurgical requirements within the specified delivery time. It did so using its single-point accountability program. The shop, with in-house machining and assembly capabilities, scheduled and performed all machining, including boring, milling, drilling, and tapping.

ICI cast the pedestal in F357 aluminum for a finished product weighing 10 lb with a dimensional envelope measuring 18-in. high, 12.5-in. deep, and 13.5-in. wide. According to the company, the pedestal was a dimensionally demanding component.

For instance, ICI had to hold critical pivot bores to within true positions of 0.001 in. running through the pedestal's yoke for antenna-drive movement. In addition, working with such a large casting (from a volume standpoint), ICI dealt with a number of challenges related to size, such as gating and metal feedrates.

The casting also incorporates many ribs, which made metal flow difficult. However they reduced metal mass for weight savings and increased rigidity and strength.

ICI also prototyped with a plastic pattern, which is produced without tooling. This presented additional variables to overcome because the patterns react differently than production wax ones.

RDR 4000 systems mount inside the radomes, or nose cones, of commercial and military aircraft. They detect adverse weather conditions such as wind shears.

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