A unique project tests State Line’s skills with decorative castings
The majority of the castings State Line Foundries produces are used in unglamorous but vital products like industrial pumps, mining equipment and military vehicles. When the foundry recently had the opportunity to take on a unique decorative castings project for a major American city, it was a perfect opportunity to expand its range of work.
LampLight Decorative Lighting needed a foundry to produce 150 decorative bases for new 5G cellular poles being installed by the Toro Blanco Group to support next-generation voice and data services in the city of New Orleans. LampLight offers hundreds of pre-designed, configurable components and can also fabricate custom design solutions for outdoor lamp lighting.
These circular bases, which stand about 5 feet tall and weigh over 600 lbs., support smart poles that contain a variety of 5G electronics. They needed to have a historic appearance, finished with a pattern that resembles a ship’s rope tilted at a 45-degree angle. Ductile iron was selected to provide an old-fashioned look while also protecting the poles and their high-tech contents.
This project required the casting of 300 half-bases. LampLight drilled and tapped holes in each of them so the two halves could be bolted together around the pole. They then painted them in a primer color and shipped them to New Orleans. The city painted them to match the historic look of its street lamps and then installed them around the poles.
LampLight found State Line Foundries via a web search and was impressed with the variety of services it provided and its level of passion and patience with the project. “They were very interested in exploring a project that was beyond their usual scope of work,” explains owner Chris Morris. “They were responsive and worked very hard to make sure that the castings met our needs.”
Morris provided State Line with CAD drawings, which the foundry used to have patterns built. But the design of these pole bases presented several challenges.
“First, the rope-like design created an undercut near the parting line of the casting. The client didn’t want any draft or material added that would change the aesthetics of the finished pieces. Nor did they like the idea of positioning the rope pattern horizontally on these castings, which would have enabled us to use a simpler pattern,” recalls State Line Foundries President Jesse Milks. At least 1-2 degrees of draft are required with most patterns to ensure that the castings will release from them.
“Ultimately, the pattern was designed with two loose pieces to accommodate the 45-degree angled ribs. The loose pieces were drawn off the pattern with the mold. Then, we removed the loose pieces from the mold at a different angle. Finally, we placed the loose pieces back on the pattern for the next piece to be cast,” he adds.
In addition, when State Line produced the first test castings, they had grinding marks on the outside where the in-gates were removed. These are the openings where the molten iron enters the pattern to fill it. They needed to be cut off the finished part and ground smooth with the surface of the casting.
While this may be acceptable for industrial parts, it didn’t meet LampLight’s need for a decorative casting with a high-quality finish and a perfectly-aligned seam between the two halves.
To solve this problem, State Line engineers devised a clever gate core system that placed the in-gates on the inside of the casting, where no one could see the grind marks after the pole bases are installed.
“Our team used some old pattern-maker tricks and creativity to solve both problems,” Milks points out.
Morris is pleased with how these castings turned out and has sent several other projects to State Line since it completed the pole bases. “We work with several foundries in the Midwest and southeast to produce castings for our many lighting projects. I’m pleased to add State Line Foundries to that list,” he said.
Likewise, Milks appreciates the opportunity to expand his team’s capabilities in a new direction: “They don’t usually get to make fancy castings. They enjoyed the opportunity to make something unique that’s a highly visible part of the New Orleans experience.”
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