ExOne may be the most committed and experienced metal 3D printer company in the world. Since 1995, ExOne has dedicated itself to creating parts made from powdered metal and sand—and nothing else—using a proprietary binder jetting technology. As metal remains the first choice of engineers in their product designs and the status of plastic suffers from its growing environmental impact, metal 3D printing of parts is sure to be considered more seriously as a manufacturing option.
ExOne was displaying its latest 3D printers at AMUG 2021, recently held in Orlando, Fla. Its biggest competitors were not, playing safe during the pandemic. It was time for ExOne to shoot ahead of the pack.
Metal Heads
Due to its focus on metal, ExOne has had more time to deal with—and fix—the issues of printing in metal—issues that are considerable and potential deal breakers for engineers who staked their reputations on metal parts formed by time-worn traditional methods. Forging, casting and machining have withstood the test of time. They provide precision, confidence, low risk … qualities that engineers hold dear. Those parts can be counted on; they won’t fail. Introducing a new process (3D printing of metal) can introduce doubt in many words (voids, uneven powder distribution, melt pools, porosity, distortion…) and problems you never had.
Engineers demand that any new process be put to the test. Accepting parts made from powder or wire—parts to be thrust into space, and used in military vehicles, automobiles, human bodies … any exacting environment—is not automatic. The concept of producing a part by building it bit by bit—rather chipping away at a block of material—does make sense immediately. The part will cost less in terms of energy, it will use less material, and so on. But expecting that material to turn solid to powder, and then back to solid again, and be the same, is still wishful thinking. We wish we could transport like in Star Trek, too.
ExOne is introducing a printer that can form parts from 6061 aluminum alloy powder. Aluminum alloy 6061-T6 (the suffix designates hardening) is favored by the aerospace industry.
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How Much?
What will it cost to make this part with a metal 3D printer is the burning question for product engineers testing the waters of powdered metal—and one that can be answered quickly with ExOne’s part estimator. The part estimator will instantly estimate how much a 3D-printed metal part will cost for a material. Oh, you don’t have a metal 3D printer available? If $2 million for a metal 3D printer and the space it will need to occupy is too much for you, ExOne can quote you a price to make the part and ship it to you.
ExOne’s reason for existence is not to produce metal parts and not to make the machines themselves, but Lucas sees offering the part making service as the best way of making the process real for the product engineer.
“What am I going to pay is always an early question,” said Lucas, who will let ExOne’s part estimator answer it. Lucas sees the part estimator as a sales tool.
“If we can show the part is going to be within 30 percent to 40 percent of what people are paying now, then they will want to take a look at us. But if we’re 10x or 20x more, then it’s probably unlikely. Then the look opens it up to other benefits like reduction in volume and less material cost, for example.”
“ExOne’s main goal is selling machines—that’s our business. But when you have the number of different materials that can be run on machines, and there’s no customers that can make parts from that material, we offer what we call benchmarks. Customers have a part and they ask if that part can be made with binder jet printing. What will the quality be like? Will it hold its shape? We’ve got several machines devoted to benchmarks.”
Is it worth it, we ask? The parts are sold for hundreds of dollars, while the machines sell for hundreds of thousands of dollars. Does it put ExOne in competition with its customers, many of whom could be in service bureaus?
“It’s a great screening tool,” said Lucas. Otherwise, ExOne would be swamped by tire kickers looking for free sample parts. With all the demand for metal 3D printing parts, he does not see ExOne offering this one-off benchmarking as putting a dent into service bureau business. In fact, the customer who orders the benchmark will be passed on as a sales lead to a service bureau in their area for higher volume of parts.
The ExOne Production Metal Cost Calculator requires an estimate of nesting—probably not what a product engineer will have off the top of his or her head. A high nesting value will reduce the cost of a part dramatically as more parts can be created from one build—the printhead is more productively utilized and less powder is wasted. Since the tire kicker, unaccustomed to nesting, will probably make a wild guess or accept defaults, ExOne cautions that the calculator should not be solely relied on as an accurate measure of true cost. And as ExOne itself points out on its helpful blog posts, automatic nesting routines are not able to optimize nesting as well as a skilled operator.
ExOne’s Quick Ship Calculator Instant Quoting engine is far more accurate and is still quite easy to use. ExOne has embedded AMFG calculator, favored by 3D printing service bureaus, to estimate the cost of a part. After you give ExOne your email address, you can drag in a solid model part file. The part displays in the built-in viewer. You can rotate and zoom in and out. One part flashed a message that it was being repaired, but we imagine the automatic repair is minor. You select the material you want to use and, voilà, the quoting engine will give you a cost. The delivery time stayed at “about 10 days” unless the part required “special attention,” in which case it jumped to “about 15 business days” and refused to offer a cost when we used some of ExOne’s more esoteric materials.
What is it about ExOne’s machines that gives the company an advantage over its competitors, even those who are using binder jetting technology?
“Probably the biggest differentiator between us and the others is we allow our customers to adjust a lot of things on our machines,” said Lucas. “We intentionally allow customers to adjust a lot of things on the machine. We use piezoelectric printheads, so that lets us use a lot of different binder types. We allow customers to adjust this timing between spreading jetting drying. That allows them to run a lot of different materials.”
Lucas is understandably proud of his company’s products. We can tell how, as a champion of technology, he does not work for anyone else.
“The quality of the products coming out of our machine is outstanding. This is done on one of our machines,” he said, pointing to a steel engine block (first picture). “It’s a single alloy 316L material. You won’t see anybody else in the industry in binder jetting showing parts of this size, with this good shape control. That’s because we have a really good consistent material density in our parts. I really do think we’ve got the best dispensing, spreading, compacting technology for these very fine powders.”