Casting maker complements traditional methods with an additive

Embrace additive manufacturing authorized casting manufacturer DW Clark to reduce certain tooling production costs by up to 90% compared to traditional methods, enabling the development of parts that attract new business.

“Customers come to us with parts that they no longer have manufacturing options for, which we’ve been able to do with 3D printing,” says Jeff Burek, president of DW Clark. “Due to the addition of add-ons to the store, our [book of business] probably grew, easily I would say 15% taller.

“A lot of the customers we have now, we have it because we gain their trust by using additives and then they place additional business for parts that could use traditional products. [manufacturing], and it could be higher volume coins. We made the prototypes with additives, and then you go to higher production tools,” says Burek.

Easier and faster manufacturing with additive

DW Clark manufactures low to medium volumes of castings – a typical production run ranges from a few hundred to thousands of parts – primarily for aerospace and defense. Most parts weigh between 1,200 pounds and 2,000 pounds, including motor housings, pump components, and large valve bodies for fluid handling. For these parts, traditional metal casting methods are best.

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

DW Clark operates three facilities in Massachusetts. Burek operates the company’s largest plant, located in Taunton, Massachusetts. He eventually realized that additive manufacturing presented a much better way to make cores.

“The additive eliminates the need to assemble multiple pieces of a core and then place them in a mold,” says Burek. “You can often just 3D print it as one solid piece. And similarly on the mold side, you don’t need any drafts or hassle to pull that tool or shape out of the sand.

DW Clark made his first foray into 3D printing in 2014, buying sand-printed molds from a 3D printing company ExOne to test the replacement of the traditional CNC method for making tooling for sand mold cavities.

“It got to a point where we were using quite a high volume of 3D printed molds, so we bought a printer in 2018 and installed it in our factory in Taunton,” says Burek. With the technology in-house, the company could iterate quickly as well as at a lower cost compared to purchasing the molds from an external vendor.

Employees, from shop operators to engineers, were on board with the adoption of the new technology. “The moulders to make traditional moulds. I think they are fascinated by [additive]. It’s not like it took away the need for what they’re doing,” Burek says. “I would describe [additive] as increasing. They are able to produce more. Those core assemblies that used to be tricky, now they can use a 3D printed core and just drop it into the mold. It saves them a lot of time, trouble and frustration on some of the really tricky or tricky projects.

“Engineers love it because it’s so easy to replicate better designs,” adds Burek. “There is no interruption between the model and what it sends to the printer. It’s just a more controllable process from their perspective.

The speed of additive manufacturing allows DW Clark to quickly iterate on designs and address these weaknesses. “Let’s say your molder or your operator is having trouble handling this mold. You can just 3D print handles or a lifting mechanism directly into that mold and solve the problem,” says Burek. “You have a lot more problem-solving ability than if you had fixed tooling, you have to physically make adjustments to the tool, which can take a long time.”

The challenge of adding additive

Adoption of additives creates challenges for equipment maintenance. DW Clark has field employees with extensive experience in the maintenance and repair of CNC machines. The company can only perform relatively basic maintenance and repairs on 3D printers and must rely on the equipment manufacturer for anything more complex.

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

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

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

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

At the end of Q1 2021, DW 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 designs that needed to be refurbished. It also reduces the need for storage.

“One of our facilities stores nearly 40,000 square feet of tooling,” Burek explains. “With rising property prices and the rising cost of that storage. And these tools need to be maintained. Every time you are going to use them, you should re-inspect them and make sure everything is in good condition before putting this tool into production. It is easier to turn to additive machines instead.

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