Released on August 18, 2011

Portage Casting & Mold Inc., Portage, Wis., has completed production of two metal castings for the Univ. of Wisconsin-Madison that will form the framework of a simulated “dynamo,” the force within celestial bodies that creates a magnetic field.

The two castings, each weighing 5,100 lbs. after they are machined in-house, were combined to create a nearly 10-ft. sphere that holds high-temperature plasma in a vacuum. The apparatus is designed to replicate phenomena like the Earth’s core and allow scientists at the Univ. of Wisconsin-Madison to study a dynamo up close.

According to Dan Griep, Portage Casting’s director of tooling, the cope and drag mold weights for the castings exceeded 70,000 lbs., and the pour weights were 10,700 lbs. To accommodate the size of the castings, the metalcasting facility used 14-ft. flasks. Special rigging equipment was required to roll over the drag mold‬.

“A lot of geometry was built with core sections,” Griep said. “The cope mold was an assembly of four flasks. That had to be done because [the casting] had to be partitioned off in different sections.”

The dynamo experiments, being conducted by the physics department at the Univ. of Wisconsin-Madison, have been funded in part by a $2.4 grant from the National Science Association. According to Griep, the experiments performed with the apparatus last a tenth of a second and use all the energy that can be generated in the laboratory.

“Originally, these types of vessels were fabricated in stainless steel,” Griep said. “This is the first time this was done in aluminum. Our [castings’] overall integrity is as good as the sphere itself, and the bottom line is significant cost savings.”

Portage Casting provides aluminum castings, molds and other services primarily to the plastics and foundry industries from its 100,000-sq.-ft. facility in Wisconsin.

“I would say [the dynamo] was definitely not a normal job for us,” Griep said. “But by the same token, it is not the biggest item we do here.”