How a manufacturer brought 3D printing into the foundry

When you think of 3D printing, you probably don’t think of metal casting. But in fact, 3D printing has been a huge help to foundries thanks in large part to one Ohio-based company, Humtown Products.

In 2014, the family-owned business decided to try using 3D printers to create castings for engine blocks in cars, trucks, construction equipment and aerospace technology. Since then, Humtown has led an industry-wide transformation of metal casting and will be recognised at the 2020 Manufacturing Leadership Awards in October for commercialising 3D printing in the sector.

How it works: Ordinarily, metal casting involves creating a tool or pattern from materials like plastic or wood, then packing sand tightly around the pattern to form a mould. Then workers pour metal into the mould, creating the finished component. But with 3D printing technology, Humtown can skip the tooling stage entirely, printing the sand mould through software commands instead.

How they did it: Back in 2014, there were only a few sand-casting 3D printers in north America. They were mostly used for prototyping and cost two million dollars each. Because the technology hadn’t been widely used, Humtown struggled to find a bank that would finance a loan. The company ended up working with America Makes and partnering with local schools like Youngstown State University and the University of Northern Iowa, which was primarily using the technology for prototyping at the time.

Brandon Lamoncha, who is now Director of Additive Manufacturing at Humtown Products, spent three years traveling to and from Iowa to study the technology, while also traveling to foundries around the country to spread the word about 3D printing. He made the case that a new wave of technology was coming and that, if American foundries didn’t embrace it, they would be left behind the curve and possibly out of business.

“When we got into this game,” Lamoncha says, “you could count on one hand the number of 3D sand printers in North America. Now there’s 40 or 50.”

The benefits: The technology has been effective for a number of reasons.

It’s faster: Using traditional methods, it might take 18 to 20 weeks to develop the tooling to make a cylinder head for a customer’s car. Now, Humtown can receive the data they need on a Friday, run their printers over the weekend and start pouring metals on Tuesday or Wednesday.
It’s more efficient: A lot of machining involves subtractive technology. For example, you might take a hunk of aluminium, carve out what you need and discard what you don’t. With 3D printing technology, Humtown is using additive manufacturing instead. They’re starting with nothing, and building only the things they need.

It’s powerful: The technology allows the metal casting industry to make parts that were once too complicated to make using conventional processes. For example, complex volutes for pumps were made in sections in the past. But 3D printing allows the parts to be made all together.

It’s creative: 3D printing allows Humtown to produce novel designs that weren’t possible to make with tooling. Now, the company can take full advantage of the creativity of their engineers.

The result: Six years ago, 3D printing was used in less than two per cent of sales at Humtown. Today that number has risen to 40 or 50 per cent.

The last word: “In hundreds of years, nothing has been this big of a paradigm shift,” said Lamoncha. “Humtown has been around since 1959. Casting has been around since the Egyptians, and not a lot has changed in the metal casting industry. This kind of change? This is amazing.”

For further details visit The National Association of Manufacturers website