© Mastercard Popov | Dreamstime.com

Casting Manufacturer Complements Traditional Methods with Additive

Aug. 12, 2022
Slashed part prototyping costs lead to company growth.

Embracing additive manufacturing allowed casting manufacturer D. W. Clark to slash some tooling production costs up to 90% versus traditional methods, enabling part development that attracts new business.

“Customers come to us with parts that they’ve run out of manufacturing options for that we've been able to do with 3D printing,” says D. W. Clark President Jeff Burek. “As a result of adding additive to the shop, our [book of business] probably grew, easily I would say 15% larger.”

“A lot of the customers that we now have, we have because we gain their trust using additive and then they place additional business for parts that might use traditional [manufacturing], which might be higher volume parts. We did the prototypes with additive and then you move into higher production tooling,” says Burek.

Simpler and Faster Manufacturing with Additive

D. W. Clark manufactures low-to-medium volumes of castings—a typical production run ranges from a couple hundred to thousands of parts—primarily for aerospace and defense. Most parts weigh between 1,200 pounds and 2,000 pounds, including casings for engines, pump components, and large valve bodies for fluid handling. For these parts, traditional metal casting methods serve best.

Some of these parts, however, also have delicate internal structures with wall thicknesses as small as one-eighth of an inch. Cores, or tools or patterns used to create these internal passageways, were also historically created via traditional metal casting.

D. W. Clark operates three facilities in Massachusetts. Burek runs the company’s largest plant, located in Taunton, Massachusetts. He eventually came to realize that additive manufacturing presented a much better way to manufacture the cores.

“Additive eliminates the need of assembling together multiple pieces of a core and then having to set that in a mold,” says Burek. “You can often just 3D print it in a single, solid piece. And similarly, on the mold side, you don’t need draft or have to worry about extracting that tool or form from the sand.”

D. W. Clark made its initial foray into 3D printing in 2014, purchasing sand-printed molds from 3D printing company ExOne to test replacing the traditional CNC method for manufacturing tooling for sand mold impressions.

“That got to a point where we were using a pretty high volume of 3D printed molds, so we bought a printer in 2018 and installed that in our Taunton facility," says Burek. With the technology in-house, the company could iterate quickly as well as cheaply compared to purchasing the molds from an external supplier.

Employees from shop floor operators through engineers were on board with adopting the new technology. “The molders for making traditional molds. I think they’re fascinated by [additive]. It’s not like it’s eliminated the need for what they do,” says Burek. “I would describe [additive] as augmenting. They’re able to output more. These core assemblies that were difficult, they can now use a 3D printed core and just drop it into the mold. That saves them a lot of time and difficulty and frustration on some of the really touchy or delicate projects.”

“The engineers love it because it’s very easy to reproduce better designs,” adds Burek. “There are no interruptions between the model and what they’re sending to the printer. It’s just a more controllable process from their standpoint.”

The speed of additive manufacturing allows D. W. Clark to quickly iterate designs and address these foibles. “Say your molder or your operator is having trouble handling that mold. You can just 3D print in handles or a lifting mechanism right into that mold and solve the problem,” says Burek. “You have a lot more ability to address things whereas if you had fixed tooling you have to physically make adjustments to the tool which can be very, very time-consuming.”

The Challenge of Adding Additive

Adopting additive creates equipment maintenance challenges. D. W. Clark has employees on the floor with extensive experience maintaining and repairing CNC machines. The company can only perform comparatively basic maintenance and repairs on 3D printers and has to rely on the equipment manufacturer for anything more complex.

That said, Burek says finding technicians for legacy equipment can also be difficult sometimes and 3D printer manufacturers provide excellent service in his experience.

Burek adds it’s important for manufacturers that adopt additive to understand where the technology doesn’t make sense, owing in part to the added expense of the powdered metal used for sintering in direct metal printing compared to the cost of raw materials for casting. Speed is also an important factor to consider.

“I think direct metal printing for smaller parts is the way to go—smaller parts means like a foot by a foot or less—but the per pound cost of the raw material that’s getting sintered for direct metal printing is typically already more expensive than our finished product cost, and that’s by a pretty good margin. And the time it takes to 3D print something goes up exponentially with the volume,” says Burek.

“To 3D print, a pattern the size of a loaf of bread might take 48 hours to print out of plastic. We could probably print on one of the sand printers the equivalent of say 60 loaves of bread in about eight hours, and then cast into those molds,” he adds.

At the end of Q1 2021, D. W. Clark purchased a second additive machine with a larger envelope capable of printing at higher definition than the company's first machine. Burek estimates that additive parts have now replaced between 10% and 15% of the company's tooling, replacing existing mold patterns that needed refurbishing. It also cuts down on the need for storage.

“One of our facilities stores almost 40,000 square feet of just tooling,” Burek says. “With real estate prices rising and increasing the cost of that storage. And those tools have to be maintained. Every time you go and use them you’ve got to re-inspect and ensure everything is in good order before you put that tool into production.” It’s easier to turn to additive machines, instead.

About the Author

Dennis Scimeca | Technology Editor, IndustryWeek

Dennis Scimeca is a veteran technology journalist with particular experience in vision system technology, machine learning/artificial intelligence, virtual and augmented reality, and interactive entertainment. He has experience writing for consumer, developer, and B2B audiences with bylines in many highly regarded specialist and mainstream outlets.

At IndustryWeek, he covers the continuing expansion of new technologies into the manufacturing world and the competitive advantages gained by learning and employing these new tools.

He also seeks to build connections between manufacturers by sharing the stories of their challenges and successes employing new technologies. If you would like to share your story with IndustryWeek, please contact him at [email protected].