Additive manufacturing, or three-dimensional (3D) printing, has transformed the metalcasting industry and has been a critical innovation for improving efficiencies in sand and core making. Since the 1980s, computer-aided designs (CAD) have gained mainstream traction and have allowed engineers and designers to create, modify, and optimize designs to produce 3D models. 

Indeed, 3D printing using CAD has recently exploded in the metalcasting industry as 3D printing offers a plethora of benefits including increased speed, better precision, reduced costs, better surface finishes, increased design complexity, and optimized castings. The evolution of printing has had widespread effects on foundries and customers today.

“I’ve witnessed a significant evolution in the use of 3D sand printing in foundries over the last 30 years, with significant acceleration in the past decade,” said Kelley Kerns, director of new business development at AFS Corporate Member HA International and a member of the AFS Additive Manufacturing Division. “While many examples stand out, [AFS Corporate Member] Grede Iron Mountain’s case continues to impress me the most.” 

“By consolidating multiple cores into a single printed piece, Grede eliminated the need for expensive coreboxes, reduced energy costs (gas/electric), reduced assembly time and improved accuracy, plus they were able to reallocate people to other higher value areas in the foundry,” he continued. “[This change] exemplifies the transformative potential of 3D sand printing in traditional foundry operations. It highlights not only significant cost reductions but also substantial efficiency improvements, highlighting how even high-production foundries can benefit from this technology.” 

Dave Rittmeyer, director of business development at AFS Corporate Member Matthews International who also volunteers on the AM Division, says using 3D technology eliminates casting draft and allows for control and great detail––a feature that only 3D printing allowed his team to produce an intricate anchor that won recognition in the 2024 AFS/Casting Source Casting Competition. 3D printing relieves the casting industry of challenges such as delivering with a tight turnaround, reducing downtime, and finding skilled workers. Rittmeyer emphasized that finding employees with the skillset to work on these projects is difficult, and 3D printing alleviates this pressure.

Kern echoed the labor challenges that most foundries face. “With the ability to produce complex cores as single pieces, 3D sand printing helps offset labor challenges and reduces assembly time.” 

Sources agree 3D printing molds and cores give foundries a competitive advantage when it comes to tooling price, accuracy, speed of production, and the ability to modify existing jobs with super-fast turnaround times.

Marshall Miller, applications engineer at 3D Systems and AFS AM Division member, added, “There is a financial advantage to using extrusion 3D-printed patterns supplemented with binder-jet 3D-printed cores without a loss in time compared to typical printed sand deliveries.” 

This combination process also works well for 3D Systems when using aggregates, including synthetic aggregates, and Miller suggests this approach for small foundries that do not have the budget for expensive sand printers.  

“A hybrid production strategy combining conventional sand mold making with 3D printed complex cores is gaining popularity,” said Kerns, “offering competitive advantages to foundries. Even a strategy that incorporates additive with subtractive manufacturing will play a key role in the approach. 3D sand printing is becoming more cost-effective for larger quantities, making it viable for mass production applications.” 

For foundries with budget constraints that prohibit large capital investment for inhouse 3D printing, several core shops and service bureaus have 3D sand printers and ship cores throughout North America, Kerns added, “giving foundries options to purchase 3D sand printed cores as strategy versus purchasing a machine.” 

More to Come

Miller believes the future is bright for additive manufacturing.

“I believe they will continue to get faster and faster,” he said. “This will result in lower costs and faster delivery of molding and core equipment.”

He recommends that foundries who are interested in 3D print capabilities join the AFS Additive Manufacturing Division to gather input from others who have learned from experience in the 3D space and get ideas to avoid reinventing the wheel. 

In the future, Kerns said he expects to see the development of more environmentally compliant materials for 3D sand printing (such as inorganic binders), focusing on reduced emissions and improved sustainability.

CAD will continue to advance in creativity, productivity, and efficiency, sources said. The possibilities in the 3D space appear endless as CAD has the ability to integrate generative design, artificial intelligence, and machine learning into their systems. The machines will learn, and so will humans, as experiences in the field are shared. 

An ExOne Case Study: Forward 
Thinking with Reverse Engineering 

To support the rigorous demand for maintenance and wear parts for chemical, petrochemical, oil, and gas industries in the Alberta oil sands, AFS Corporate Member Demir Engineering, a materials solutions and engineering service provider in Edmonton, made a major equipment investment to add an S-Max Pro binder jetting system from AFS Corporate Member ExOne.

With a core focus on engineering materials for severe conditions, the company’s modern business model focuses heavily on digital processes. 

“We put in the engineering work up front with customers,” said Matt Carver, Business Development Manager at Demir. “Our team supports design, modeling, and simulation in order to allow clients to use a just-in-time inventory strategy.” 

With the importance of uptimes for the surrounding energy sector––where downtime often costs production tens of thousands of dollars per hour––the speed of binder jet 3D printing on the S-Max allows Demir to service the quick-turn casting market.

Printing directly from a CAD model, Demir eliminates the production time of traditional patterns and core boxes. 
“We use the S-Max as our full tooling factor,” Carver said, noting how the foundry offers fast turnarounds with digital production. “We had a CNC router to build wood conventional tooling, but we’ve actually packed that up since bringing in binder jetting.”

A mining customer of the foundry recently required a coupling to replace one that had failed in service. The OEM quoted a five- to six-month turnaround time for a replacement part. However, with an estimated downtime cost of $40,000 per hour, the mining company turned to Demir for a rapid replacement. After reverse engineering the part from a 3D scan, the team simulated the pour, printed the entire mold package on the S-Max, and sent the brass casting out to be finished machined a mere five days later. 

Producing local quality castings reduces lead times while also reducing the carbon footprint of the overall production process. “That’s where I get excited being a business development manager,” Carver explained. “We can produce these parts in North America rather than making them overseas, plus scrap reduction from our engineering and all these benefits from our process that support green initiatives and circularity brought back into North American production.” 

A 3D-Systems Case Study: 
Transformed by Additive Manufacturing

Astech, Alloy Steel Technologies Inc., a steel and iron sand casting foundry headquartered in Vassar, Michigan, has spent the last two decades leveraging technology, including pellet-extrusion additive manufacturing, to transform their business. 

Beginning in 2018, the company invested in a trio of medium-format filament extrusion (FFF) 3D printers––but the foundry still lacked an in-house AM solution for patterns larger than 24-in. in any dimension. Tasked with finding a large-format printer that would meet their needs, Astech Engineering Manager Bob Helwer discovered a solution during a presentation at the AFS Additive Manufacturing Conference in the fall of 2018. The presenter was Clay Guillory, founder of Titan Robotics, maker of large, industrial pellet-extrusion 3D printers, which was acquired by 3D Systems in 2022.

“I couldn’t believe how fast [the printer] was and was sure that the video had been sped up until Clay mentioned in his presentation that the video was recorded in real-time,” Helwer said. The speed and economy of printing directly from pellets represented a clear advantage over competing filament-based systems he had researched. 
Astech purchased a Titan Robotics Atlas (now called EXT 1070 Titan Pellet) 3D printer, which was installed in August of 2020. Positive ROI was achieved within 18 months of installation and four years later, Astech’s Titan printer is still going strong. 

Today, Astech 3D prints roughly 90% of their patterns. “In-house additive manufacturing has become our ‘secret sauce.’” Indeed, the speed and cost advantages of additive manufacturing have enabled Astech to grow, boost their profitability, and continue delivering high quality cast products to their customers.

A Humtown Case Study: Early 
Adopters of Printed Sand Cores

AFS Corporate Member Humtown says it is proud to partner with foundries that are excited to integrate new technology and move the dial in 3D printing. 

AFS Corporate Member Watry Industries, an aluminum casting foundry in Sheboygan, Wisconsin, and early adopters of 3D technology, were fully on board when Humtown offered to provide printed sand cores for their original equipment manufacturing clients. Watry needed a large casting, so Humtown initially intended to use a traditionally produced core after testing the design of the core. However, once the team started looking at the tolerances and requirements, both partners agreed that 3D printing was the best method for production. 

CAD is also important for physically prototyping large equipment at early design stages. Maintaining effective collaboration and establishing clear expectations were key to the outcome of this project, which did not come without hurdles. 

As the requested product was significantly larger than other castings Humtown had made before with 3D printing, these cores required the use of several machines during peak production months, so Humtown was determined to avoid a bottleneck situation. The process could not stall production as the product was in high demand. Humtown determined the frequency and cadence in which the product could be made, and in turn, Humtown and Watry were successful and timely in delivering what was expected––3D printed sand cores.