The Foundry of the Future is Here

July 18, 2022
3D printing of sand cores is underway at Grede’s Iron Mountain, Mich., plant, speeding up product development, enhancing quality and consistency, saving tooling costs – and helping to define a new role for the foundry and its people.

The “foundry of the future” is a favorite discussion topic among metalcasters, and it has been so for decades. It seems possible that the foundry of the future, or some aspects of it, has already arrived – and if it that’s so then Grede’s Iron Mountain, MI, plant is an example.

That’s where two ExOne 3D sand printers have been installed to produce cores for casting iron components, and that has initiated a new approach to foundry operations. The first printer, an ExOne S-Max model, was installed in 2018, followed by an ExOne S-Max Pro unit in 2021.

“I think we were looking for replacement technology,” recalled Tyler Hill, “something that gave us more flexibility to eliminate the need for assembling multiple cores… and something that allowed us to do more with casting designs.”

At the time of the installation Hill was the Iron Mountain foundry’s plant manager, though now his responsibilities have expanded as Grede’s group vice president, Commercial/Industrial. He oversees activities supporting customers in Class-8 truck, agricultural and construction equipment markets at five Grede foundries.

The initial S-Max unit is capable of printing furan or CHP bonded sands, with a large build platform (1,800×1,000×700 mm; 70.9×39.4×27.6 in.) that supports high volume, series production – but is also effective for prototyping. It has a build volume 1,260 liters (44 ft³), and a maximum build rate of 125 l/hr.

The second machine, the S-Max Pro, has a comparable build platform and build volume, but its build rate is 145 l/hr.

While the Iron Mountain foundry continues to operate some standard core-shooting machines, the 3D printers have introduced new possibilities for speed, precision, and simplicity in overall production. “By nature, 3D printing contributes to precise, higher quality components,” CEO Cary Wood stated. “We saw the potential for additive manufacturing to support greater repetition of complex core constructions and invested in new equipment to make it a reality at Grede.”

“It’s kind of a Swiss army knife,” Hill explained of the sand 3D-printer. “It does a lot for us. It does prototyping and some other things, but it also is a great production unit. And we run up to 220,000 pieces a year through that machine.”

Design flexibility has emerged as a particular advantage to 3D-printing sand cores. It has meant that the foundry can adopt new production programs or resolve problems with current designs faster than in the past – which underscores Grede’ value to the casting buyers.

“There are so many benefits to sand 3D printing,” Tyler Hill said. “The speed-to-market, quality improvement, repeatability, and savings on tooling are just a few of the advantages 3D printing offers our customers. The true value in 3D printing, however, is in the creative freedom that allows us to have a more collaborative relationship with our customers. It moves our foundry out of the ‘price per pound’ equation and makes us an invaluable development partner for our customers.”

On that point, the Iron Mountain foundry is now supporting other Grede operations with cores for some production programs, as well as prototyping projects. Mustering its 3DP capabilities and the expanding understanding of 3DP at Iron Mountain, Grede is able to collaborate with customers to redesign cast parts.

“We have a customer we’ve been working with for years and we’re now closer than ever because we can make design changes on the fly,” according to Tyler Hill. “We can accommodate their requests and continue to optimize the design with them.”

The new opportunities presented by 3DP position Grede to respond appropriately to changes in the supplier-customer relationship: New production programs that materialize due to product redesigns, reshoring, or other factors, give the foundry leverage in the supply chain. And the reliability and consistency of the 3DP process means the Iron Mountain foundry can grow from that position.

If 3DP is the basis of all these changes then it is one aspect of the “foundry of the future” that so many – including Tyler Hill – expect to see.

“When I speak about the ‘foundry of the future’, I’m talking about a foundry where technology and people are tied together to a greater extent, … more of a design-focused and automated enterprise that gets us into processes that allow for quicker changes, quicker innovation. And that’s the plan that we’re deploying at Iron Mountain.”